在ImageView Blackberry 10中动态设置imageSource [英] Dynamically set imageSource in ImageView Blackberry 10

查看：229 发布时间：2016/10/19 21:41:17 c++ qt4 qml blackberry-10 blackberry-cascades

本文介绍了在ImageView Blackberry 10中动态设置imageSource的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！

问题描述

请帮助我，我卡住了这一个多星期。我发出一个信号与图像从我的cpp文件。我需要替换我放置在imageView在QMl使用这个发射的图像的默认图像。
这是我的完整代码。

PostHttp.hpp

  / *版权所有（c）2012 Research In Motion Limited。 
 * 
 *根据Apache许可证2.0版（许可证）授权; 
 *您不得使用此文件，除非符合许可证。 
 *您可以通过以下方式获取许可证的副本：
 * 
 * http://www.apache.org/licenses/LICENSE-2.0 
 * 
 *除非适用法律要求或以书面形式同意，软件
 *根据许可证分发的软件按原样基础，
 *分发，不附有任何明示或暗示的担保或条件。 
 *请参阅许可证管理权限的特定语言和
 *许可证下的限制。 
 * / 
 
 #ifndef POSTHTTP_HPP 
 #define POSTHTTP_HPP 
 #includeqvariant.h
 #include< bb / ImageData> 
 #include< bb / cascades / GroupDataModel> 
 #include< QtCore / QObject> 
 #include< bb / data / JsonDataAccess> 
 #include< bb / cascades / QListDataModel> 
 #include< bb / cascades / Image> 
 #include< bb / cascades / ImageView> 
 #include< bb / cascades / CustomControl> 
 namespace bb {
命名空间cascades {
 class Container; 
} 
} 
使用命名空间bb :: cascades; 
 
 class QNetworkAccessManager; 
 
类PostHttp：public QObject {
 Q_OBJECT 
 public：
 PostHttp（QObject * parent = 0）; 
 bb :: cascades :: Image m_image; 
 ImageView * imageView; 
 Container * mRootContainer; 
 bool createFolder（QString path）; 
 bool openAndSaveFile（QString filePathWithName，QNetworkReply * reply）; 
 public Q_SLOTS：
 void loginWebService（const QString& body，const QString& pass，
 bool istoken）; 
 void newsFeedWebService（const qint16 num）; 
 void logoutWebService（）; 
 void imageFetcher（）; 
 void get（const QUrl& url）; 
 void post（const QVariantMap& body，const QUrl& url）; 
 
 
 Q_SIGNALS：
 void complete（const QVariantList& info）; 
 void newsfeedComplete（const QVariantList& info）; 
 void imageLoaded（const QVariant& image）; 
 
 private Q_SLOTS：
 void onGetReply（）; 
 void onNewsFeedReply（）; 
 void onImageReply（）; 
 
 Q_INVOKABLE void generatePage（）; 
 Q_INVOKABLE void loadImages（）; 
 private：
 bb :: cascades :: QListDataModel< QObject *> * m_model; 
 QImage setImage（const QImage& image）; 
 bb :: cascades :: DataModel * model（）const; 
 QNetworkAccessManager * m_networkAccessManager; 
 bb :: data :: JsonDataAccess * dataAccess; 
 
 public：
 QString token; 
 
}; 
 
 #endif

PostHttp.cpp

  #includePostHttp.hpp
 #include< QDebug> 
 #include< QNetworkAccessManager> 
 #include< QNetworkReply> 
 #include< QNetworkRequest> 
 #include< QSslConfiguration> 
 #include< QUrl> 
 #include< bb / data / JsonDataAccess> 
 #include< QDateTime> 
 #include< bb / cascades / AbstractPane> 
 #include< bb / cascades / Application> 
 #include< bb / cascades / QmlDocument> 
 #include< bb / cascades / Page> 
 #include< bb / cascades / StandardListItem> 
 #include< QFile> 
 #include< bb / ImageData> 
 #include< QNetworkReply> 
 #include< QNetworkDiskCache> 
 #include< QDesktopServices> 
 #include< bb / cascades / Image> 
 #include< bb / cascades / Container> 
 #include< bb / cascades / ImageView> 
 #include< bb / cascades / ScalingMethod> 
 #include< bb / cascades / DockLayout> 
 #include< bb / cascades / controls / activityindicator.h> 
 #include< bb / cascades / controls / scrollview.h> 
 #include< bb / cascades / controls / page.h> 
 #include< bb / cascades / NavigationPaneProperties> 
 #include< bb / cascades / Color> 
 using namespace bb :: data; 
 using namespace bb :: cascades; 
 using namespace bb :: utility; 
 QString globalTokenValue; 
 int globalUserId; 
 bool flag = true; 
 bool flag1 = true; 
 QVariantList data; 
 
 PostHttp :: PostHttp（QObject * parent）：
 QObject（parent），m_networkAccessManager（
 new QNetworkAccessManager（this）），m_model（
 new QListDataModel& *>（））{
 
} 
 
 //！ [0] 
 
 / ** 
 * PostHttp :: post 
 * 
 *使用POST数据向httpbin.org/post发出网络请求，并获取
 *响应
 * / 
 //！ [1] 
 void PostHttp :: post（const QVariantMap& body，const QUrl& url）{
 JsonDataAccess jda; 
 QByteArray jsonData 
 jda.saveToBuffer（*（& body），& jsonData）; 
 
 QByteArray postDataSize = QByteArray :: number（jsonData.size（））; 
 QNetworkRequest request（*（& url））; 
 
 request.setHeader（QNetworkRequest :: ContentTypeHeader，application / json）; 
 request.setHeader（QNetworkRequest :: ContentLengthHeader，
 QString（postDataSize）.toUtf8（））; 
 // QNetworkReply * reply = m_networkAccessManager-> post（request，body.toAscii（））; 
 qDebug（）<< json< jsonData; 
 QNetworkReply * reply = m_networkAccessManager-> post（request，jsonData）; 
 qDebug（）<< strdgfyusujnm kjh< （& url） - > toString（）; 
 if（（& url） - > toString（）
 ==http：/// GetNewsFeed）{
 connect（reply，SIGNAL（finished SLOT（onNewsFeedReply（）））; 
} else {
 connect（reply，SIGNAL（finished（）），this，SLOT（onGetReply（）））; 
} 
} 
 
 void PostHttp :: loginWebService（const QString& body，const QString& pass，
 bool istoken）{
 
 qint64 date = QDateTime :: currentMSecsSinceEpoch（）; 
 QString time = QString :: number（date）; 
 QVariantMap data; 
 QVariantMap loginData; 
 QVariantMap devicedata; 
 devicedata.insert（OS，BlackBerry OS 6.0.0.706）; 
 devicedata.insert（deviceId，232BC441）; 
 devicedata.insert（deviceModel，9800）; 
 devicedata.insert（screenSize，480x360）; 
 loginData.insert（device，devicedata）; 
 loginData.insert（email，*（& body））; 
 loginData.insert（password，*（& pass））; 
 loginData.insert（requestDate，/ Date（+ time ++200）/）; 
 data.insert（apiKey，4f74721be9b51f24f065b044）; 
 data.insert（data，loginData）; 
 data.insert（requestDate，/ Date（+ time ++200）/）; 
 if（istoken）{
 
} else {
 data.insert（token，）; 
} 
 const QUrl url（
http：/// LoginRequest）; 
 post（data，url）; 
} 
 
 void PostHttp :: newsFeedWebService（const qint16 num）{
 
 qint64 date = QDateTime :: currentMSecsSinceEpoch（）; 
 QString time = QString :: number（date）; 
 QVariantMap data; 
 QVariantMap newsfeedData; 
 newsfeedData.insert（postId，0）; 
 newsfeedData.insert（requestType，2）; 
 newsfeedData.insert（requestedCount，num）; 
 newsfeedData.insert（userId，globalUserId）; 
 data.insert（apiKey，4f74721be9b51f24f065b044）; 
 data.insert（data，newsfeedData）; 
 data.insert（requestDate，/ Date（+ time ++200）/）; 
 data.insert（token，globalTokenValue）; 
 const QUrl url（
http：/// GetNewsFeed）; 
 if（flag == true）{
 post（data，url）; 
} 
 
} 
 
 void PostHttp :: logoutWebService（）{
 qint64 date = QDateTime :: currentMSecsSinceEpoch（）; 
 QString time = QString :: number（date）; 
 QVariantMap data; 
 QVariantMap logoutData; 
 logoutData.insert（logoutRequestType，1）; 
 logoutData.insert（userId，globalUserId）; 
 data.insert（apiKey，4f74721be9b51f24f065b044）; 
 data.insert（data，logoutData）; 
 data.insert（requestDate，/ Date（+ time ++200）/）; 
 data.insert（token，globalTokenValue）; 
 const QUrl url（
http：/// LogoutUser）; 
 post（data，url）; 
} 
 
 void PostHttp :: imageFetcher（）{
 const QUrl url（
http://upload.wikimedia.org/wikipedia/commons/e/ e7 / Nuvola_filesystems_services.png）; 
 if（flag1 == true）{
 get（url）; 
} 
} 
 
 void PostHttp :: get（const QUrl& url）{
 QNetworkRequest request（*（& url））; 
 QNetworkReply * reply = m_networkAccessManager-> get（request）; 
 connect（reply，SIGNAL（finished（）），this，SLOT（onImageReply（）））; 
} 
 / ** 
 * PostHttp :: onGetReply（）
 * 
 * SLOT 
 *从我们的http post请求中读取并返回http响应
 * / 
 void PostHttp :: onGetReply（）{
 QNetworkReply * reply = qobject_cast< QNetworkReply *>（sender（））; 
 QString response; 
 if（reply）{
 if（reply-> error（）== QNetworkReply :: NoError）{
 const int available = reply-> bytesAvailable（）; 
 if（available> 0）{
 const QByteArray buffer（reply-> readAll（））; 
 response = QString :: fromUtf8（buffer）; 
 JsonDataAccess dataAccess; 
 QVariantMap results = 
 dataAccess.loadFromBuffer（response）.toMap（）; 
 QString token =（results [Token]）。value< QString>（）; 
 int userId =（results [userId]）。value< int>（）; 
 if（globalTokenValue ==）{
 globalTokenValue = token; 
 globalUserId = userId; 
} else 
 flag = false; 
 QString success =（results [Success]）。value< QString>（）; 
 
} 
} else {
 response = 
 tr（Error：％1 status：％2）arg（reply-> errorString 
 reply-> attribute（
 QNetworkRequest :: HttpStatusCodeAttribute）.toString（））; 
 qDebug（）<<响应; 
} 
 
 reply-> deleteLater（）; 
} 
 
 if（response.trimmed（）。isEmpty（））{
 response = tr（无法检索回复）; 
} 
 qDebug（）<< response<<响应; 
 
} 
 
 void PostHttp :: onNewsFeedReply（）{
 
 QNetworkReply * reply = qobject_cast< QNetworkReply *>（sender 
 QString response; 
 if（reply）{
 if（reply-> error（）== QNetworkReply :: NoError）{
 flag = false; 
 const int available = reply-> bytesAvailable（）; 
 if（available> 0）{
 const QByteArray buffer（reply-> readAll（））; 
 response = QString :: fromUtf8（buffer）; 
 JsonDataAccess dataAccess; 
 QVariantMap results = 
 dataAccess.loadFromBuffer（response）.toMap（）; 
 data = results.value（Data）。toList（）; 
 qDebug（）<< 第一元素是< data.first（）。toString（）; 
 emit newsfeedComplete（data）; 
 
} 
} 
} 
 
} 
 void PostHttp :: onImageReply（）{
 QNetworkReply * reply = qobject_cast< QNetworkReply *>（sender（）） 
 QString response; 
 QImage img; 
 QString filePathWithName =data / img /; 
 QString imageName; 
 
 if（reply）{
 if（reply-> error（）== QNetworkReply :: NoError）{
 flag1 = false; 
 const int available = reply-> bytesAvailable（）; 
 if（available> 0）{
 const QByteArray buffer（reply-> readAll（））; 
 response = QString :: fromUtf8（buffer）; 
 img.loadFromData（buffer）; 
 img = img.scaled（40，40，Qt :: KeepAspectRatioByExpanding）; 
 const QImage swappedImage = img.rgbSwapped（）; 
 const bb :: ImageData imageData = bb :: ImageData :: fromPixels（
 swappedImage.bits（），bb :: PixelFormat :: RGBX，
 swappedImage.width（），swappedImage.height （），
 swappedImage.bytesPerLine（））; 
 QByteArray byteArray = bb :: utility :: ImageConverter :: encode（
image / png，imageData，75）; 
 qDebug（）<< bytearray is< byteArray; 
 // QVariant image（byteArray）; 
 QVariant realImage（byteArray）; 
 
 qDebug（）<< image of image is< realImage; 
 emit imageLoaded（realImage）; 
} 
} 
} 
} 
 //！ [1]

最后，我的QML档案是

NewsFeed.qml

  import bb.cascades 1.0 
 import Network.PostHttp 1.0 
 import bb .cascades 1.0 
 importcontrols
 import my.library 1.0 
 
页面{
操作：[
 ActionItem {
 title：注销
 onTriggered：{
 netpost.logoutWebService（）; 
 Application.quit（）; 
} 
 ActionBar.placement：ActionBarPlacement.OnBar 
} 
] 
 id：mainpage 
 onCreationCompleted：{
 Qt.mainImageview = imageviewid; 
} 
容器{
 
布局：DockLayout {
} 
 
 //背景图片
 ImageView {
 horizontalAlignment：HorizontalAlignment.Fill 
 verticalAlignment：VerticalAlignment.Fill 
 imageSource：asset：///images/background.png
} 
 //！ [0] 
 
容器{
 id：innercontainer 
 
 ActivityIndicator {
 id：progressIndicator 
 
 horizontalAlignment：HorizontalAlignment.Fill 
 verticalAlignment：VerticalAlignment.Fill 
 onStarted：{
 
} 
 onCreationCompleted：{
 progressIndicator.running = true; 
 
} 
 
} 
 
 ListView {
 id：listView 
 objectName：listView
 
 dataModel：ArrayDataModel {
 id：myListModel 
 
} 
 
 //覆盖默认GroupDataModel :: itemType（）行为， 
 listItemComponents：ListItemComponent {
 id：listcomponent 
 // StandardListItem是具有默认级联外观的列表的欢迎组件
 StandardListItem {
 title：ListItemData.postText 
 description：ListItemData.postDate 
 status：ListItemData.filePath 
 imageSource：asset：///images/4.png
} 
 
} 
 layoutProperties：StackLayoutProperties {
 spaceQuota：1.0 
} 
 horizontalAlignment：HorizontalAlignment.Fill 
 verticalAlignment：VerticalAlignment.Fill 
 
} 
 
 
容器{
 id：root 
布局：StackLayout {
} 
标签{
 text：ListItemData.postText 
 horizontalAlignment：HorizontalAlignment.Left 
 verticalAlignment：VerticalAlignment.Bottom 
} 
标签{
 text：ListItemData.postDate 
 // textStyle.fontSize：5 
 horizontalAlignment ：HorizontalAlignment.Right 
 verticalAlignment：VerticalAlignment.Bottom 
} 
 
 attachedObjects：[
 QTimer {
 id：timer 
 property int f： 0 
 interval：5000 
 onTimeout：{
 progressIndicator.running = false; 
 netpost.imageFetcher（）; 
 netpost.newsFeedWebService（10）; 
} 
 
}，
 PostHttp {
 
 id：netpost 
 onComplete：{
 progressIndicator.running = false; 
 progressIndicator.visible = false; 
 console.log（dsfdsafs+ netpost.model）
 timer.stop（）; 
} 
 
 onImageLoaded：{
 console.log（value is image from cpp jhgsdh+ image）
 imageviewid.setImageSource（image）
} 
 onNewsfeedComplete：{
 console.log（newsfeed的回复为+ info）
 myListModel.append（info）
 
} 
} 
 
] 
} 
 
 onCreationCompleted：{
 //创建声明场景时调用此槽
 //在此创建初始化
 console.log（Page-onCreationCompleted（））
 
 //启用布局以适应设备旋转
 //不要忘记在bar- bescriptor.xml（Application-> Orientation-> Auto-orient）
 OrientationSupport.supportedDisplayOrientation = SupportedDisplayOrientation.All; 
 
 //使用示例数据填充列表视图模型
 timer.start（）; 
 // myListModel.load（app / native / assets / mydata.json）
 
} 
 ImageView {
 ID：imageviewid 
 imageSource： asset：///images/4.png
 enabled：true 
 loadEffect：ImageViewLoadEffect.FadeZoom 
 
} 
} 
} 
}

请帮助我。

QVariant 参数定义了你的槽，但是试图使用

 QByteArray  code>  ImageConverter :: encode（）调用返回的类型。
 
 
 尝试更改你的代码的一部分，并给它一个去：
  QByteArray byteArray = bb :: utility :: ImageConverter :: encode QUrl（QDir :: currentPath（）+/shared/camera/img.png），imageData，75）; 
 QVariant image（byteArray）; 
 emit imageLoaded（image）; 
  
此外，请仔细检查您声明/定义此对信号/完全相同的参数表示法（即 imageLoaded（）信号等情况下 const QVariant&  > 
Please help me.,i m stuck with this for more than a week.I am emitting a signal with image from my cpp file.I need to replace the default image that i placed in the imageView at QMl using this emitted image.
Here is my full code.

PostHttp.hpp
/* Copyright (c) 2012 Research In Motion Limited.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

 #ifndef POSTHTTP_HPP
 #define POSTHTTP_HPP
 #include "qvariant.h"
 #include <bb/ImageData>
 #include <bb/cascades/GroupDataModel>
 #include <QtCore/QObject>
 #include <bb/data/JsonDataAccess>
 #include <bb/cascades/QListDataModel>
 #include <bb/cascades/Image>
 #include <bb/cascades/ImageView>
 #include <bb/cascades/CustomControl>
 namespace bb {
namespace cascades {
    class Container;
}
 }
  using namespace bb::cascades;

 class QNetworkAccessManager;

class PostHttp: public QObject {
Q_OBJECT
public:
PostHttp(QObject* parent = 0);
 bb::cascades::Image m_image;
 ImageView* imageView;
 Container* mRootContainer;
 bool createFolder(QString path);
 bool openAndSaveFile(QString filePathWithName, QNetworkReply* reply);
public Q_SLOTS:
void loginWebService(const QString &body, const QString &pass,
        bool istoken);
void newsFeedWebService(const qint16 num);
void logoutWebService();
void imageFetcher();
void get(const QUrl &url);
void post(const QVariantMap &body, const QUrl &url);


Q_SIGNALS:
void complete(const QVariantList &info);
void newsfeedComplete(const QVariantList &info);
void imageLoaded(const QVariant &image);

private Q_SLOTS:
void onGetReply();
void onNewsFeedReply();
void onImageReply();

Q_INVOKABLE void generatePage();
 Q_INVOKABLE void loadImages();
private:
bb::cascades::QListDataModel<QObject*>* m_model;
QImage setImage(const QImage &image);
bb::cascades::DataModel* model() const;
QNetworkAccessManager* m_networkAccessManager;
bb::data::JsonDataAccess* dataAccess;

public:
QString token;

};

#endif
PostHttp.cpp
#include "PostHttp.hpp"
#include <QDebug>
#include <QNetworkAccessManager>
#include <QNetworkReply>
#include <QNetworkRequest>
#include <QSslConfiguration>
#include <QUrl>
#include <bb/data/JsonDataAccess>
#include <QDateTime>
#include <bb/cascades/AbstractPane>
#include <bb/cascades/Application>
#include <bb/cascades/QmlDocument>
#include <bb/cascades/Page>
#include <bb/cascades/StandardListItem>
#include <QFile>
#include <bb/ImageData>
#include <QNetworkReply>
#include <QNetworkDiskCache>
#include <QDesktopServices>
#include <bb/cascades/Image>
#include <bb/cascades/Container>
#include <bb/cascades/ImageView>
#include <bb/cascades/ScalingMethod>
#include <bb/cascades/DockLayout>
#include <bb/cascades/controls/activityindicator.h>
#include <bb/cascades/controls/scrollview.h>
#include <bb/cascades/controls/page.h>
#include <bb/cascades/NavigationPaneProperties>
#include <bb/cascades/Color>
using namespace bb::data;
using namespace bb::cascades;
using namespace bb::utility;
QString globalTokenValue;
int globalUserId;
bool flag = true;
bool flag1 = true;
QVariantList data;

PostHttp::PostHttp(QObject* parent) :
    QObject(parent), m_networkAccessManager(
            new QNetworkAccessManager(this)), m_model(
            new QListDataModel<QObject*>()) {

}

//! [0]

/**
 * PostHttp::post
 *
 * Make a network request to httpbin.org/post with POST data and get
 * the response
 */
//! [1]
void PostHttp::post(const QVariantMap &body, const QUrl &url) {
JsonDataAccess jda;
QByteArray jsonData;
jda.saveToBuffer(*(&body), &jsonData);

QByteArray postDataSize = QByteArray::number(jsonData.size());
QNetworkRequest request(*(&url));

request.setHeader(QNetworkRequest::ContentTypeHeader, "application/json");
request.setHeader(QNetworkRequest::ContentLengthHeader,
        QString(postDataSize).toUtf8());
//QNetworkReply* reply = m_networkAccessManager->post(request, body.toAscii());
qDebug() << "json" << jsonData;
QNetworkReply* reply = m_networkAccessManager->post(request, jsonData);
qDebug() << "strdgfyusujnm kjh " << (&url)->toString();
if ((&url)->toString()
        ==    "http:///GetNewsFeed") {
    connect(reply, SIGNAL(finished()), this, SLOT(onNewsFeedReply()));
} else {
    connect(reply, SIGNAL(finished()), this, SLOT(onGetReply()));
}
}

void PostHttp::loginWebService(const QString &body, const QString &pass,
    bool istoken) {

qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap loginData;
QVariantMap devicedata;
devicedata.insert("OS", "BlackBerry OS 6.0.0.706");
devicedata.insert("deviceId", "232BC441");
devicedata.insert("deviceModel", "9800");
devicedata.insert("screenSize", "480x360");
loginData.insert("device", devicedata);
loginData.insert("email", *(&body));
loginData.insert("password", *(&pass));
loginData.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", loginData);
data.insert("requestDate", "/Date(" + time + "+200)/");
if (istoken) {

} else {
    data.insert("token", "");
}
const QUrl url(
         "http:///LoginRequest");
post(data, url);
}

void PostHttp::newsFeedWebService(const qint16 num) {

qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap newsfeedData;
newsfeedData.insert("postId", 0);
newsfeedData.insert("requestType", 2);
newsfeedData.insert("requestedCount", num);
newsfeedData.insert("userId", globalUserId);
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", newsfeedData);
data.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("token", globalTokenValue);
const QUrl url(
        "http:///GetNewsFeed");
if (flag == true) {
    post(data, url);
}

}

void PostHttp::logoutWebService() {
qint64 date = QDateTime::currentMSecsSinceEpoch();
QString time = QString::number(date);
QVariantMap data;
QVariantMap logoutData;
logoutData.insert("logoutRequestType", 1);
logoutData.insert("userId", globalUserId);
data.insert("apiKey", "4f74721be9b51f24f065b044");
data.insert("data", logoutData);
data.insert("requestDate", "/Date(" + time + "+200)/");
data.insert("token", globalTokenValue);
const QUrl url(
        "http:///LogoutUser");
post(data, url);
}

void PostHttp::imageFetcher() {
const QUrl url(
        "http://upload.wikimedia.org/wikipedia/commons/e/e7/Nuvola_filesystems_services.png");
if (flag1 == true) {
    get(url);
}
}

void PostHttp::get(const QUrl &url) {
QNetworkRequest request(*(&url));
QNetworkReply* reply = m_networkAccessManager->get(request);
connect(reply, SIGNAL(finished()), this, SLOT(onImageReply()));
}
/**
 * PostHttp::onGetReply()
 *
 * SLOT
 * Read and return the http response from our http post request
 */
void PostHttp::onGetReply() {
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
if (reply) {
    if (reply->error() == QNetworkReply::NoError) {
        const int available = reply->bytesAvailable();
        if (available > 0) {
            const QByteArray buffer(reply->readAll());
            response = QString::fromUtf8(buffer);
            JsonDataAccess dataAccess;
            QVariantMap results =
                       dataAccess.loadFromBuffer(response).toMap();
            QString token = (results["Token"]).value<QString>();
            int userId = (results["userId"]).value<int>();
            if (globalTokenValue == "") {
                globalTokenValue = token;
                globalUserId = userId;
            } else
                flag = false;
            QString success = (results["Success"]).value<QString>();

        }
    } else {
        response =
                tr("Error: %1 status: %2").arg(reply- >errorString(),
                        reply->attribute(
                                   QNetworkRequest::HttpStatusCodeAttribute).toString());
        qDebug() << response;
    }

    reply->deleteLater();
}

if (response.trimmed().isEmpty()) {
    response = tr("Unable to retrieve post response");
}
qDebug() << "response" << response;

}

void PostHttp::onNewsFeedReply() {

QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
if (reply) {
    if (reply->error() == QNetworkReply::NoError) {
        flag = false;
        const int available = reply->bytesAvailable();
        if (available > 0) {
            const QByteArray buffer(reply->readAll());
            response = QString::fromUtf8(buffer);
            JsonDataAccess dataAccess;
            QVariantMap results =
                      dataAccess.loadFromBuffer(response).toMap();
            data = results.value("Data").toList();
            qDebug() << "first element is" << data.first().toString();
            emit newsfeedComplete(data);

        }
    }
}

}
 void PostHttp::onImageReply() {
QNetworkReply* reply = qobject_cast<QNetworkReply*>(sender());
QString response;
QImage img;
QString filePathWithName = "data/img/";
QString imageName;

if (reply) {
    if (reply->error() == QNetworkReply::NoError) {
        flag1 = false;
        const int available = reply->bytesAvailable();
        if (available > 0) {
            const QByteArray buffer(reply->readAll());
            response = QString::fromUtf8(buffer);
            img.loadFromData(buffer);
            img = img.scaled(40, 40, Qt::KeepAspectRatioByExpanding);
            const QImage swappedImage = img.rgbSwapped();
            const bb::ImageData imageData = bb::ImageData::fromPixels(
                    swappedImage.bits(), bb::PixelFormat::RGBX,
                    swappedImage.width(),  swappedImage.height(),
                    swappedImage.bytesPerLine());
            QByteArray byteArray = bb::utility::ImageConverter::encode(
                    "image/png", imageData, 75);
            qDebug() << "bytearray is" << byteArray;
//              QVariant image(byteArray);
            QVariant realImage(byteArray);

            qDebug() << "imag of image is" << realImage;
            emit imageLoaded(realImage);
        }
    }
}
}
//! [1]
And finally my QML file is

NewsFeed.qml
import bb.cascades 1.0
import Network.PostHttp 1.0
import bb.cascades 1.0
import "controls"
import my.library 1.0

Page {
actions: [
    ActionItem {
        title: "Logout"
        onTriggered: {
            netpost.logoutWebService();
            Application.quit();
        }
        ActionBar.placement: ActionBarPlacement.OnBar
    }
]
id:mainpage
onCreationCompleted: {
    Qt.mainImageview = imageviewid;
}
Container {

    layout: DockLayout {
    }

    // The background image
    ImageView {
        horizontalAlignment: HorizontalAlignment.Fill
        verticalAlignment: VerticalAlignment.Fill
        imageSource: "asset:///images/background.png"
    }
    //! [0]

    Container {
        id : innercontainer

        ActivityIndicator {
            id: progressIndicator

            horizontalAlignment: HorizontalAlignment.Fill
            verticalAlignment: VerticalAlignment.Fill
            onStarted: {

            }
            onCreationCompleted: {
                progressIndicator.running = true;

            }

        }

        ListView {
            id: listView
            objectName: "listView"

            dataModel: ArrayDataModel {
                id: myListModel

            }

            // Override default GroupDataModel::itemType() behaviour, which is to return item type "header"
            listItemComponents: ListItemComponent {
                id: listcomponent
                // StandardListItem is a convivience component for lists with default cascades look and feel
                StandardListItem {
                    title: ListItemData.postText
                    description: ListItemData.postDate
                    status: ListItemData.filePath
                    imageSource: "asset:///images/4.png"
                }

            }
            layoutProperties: StackLayoutProperties {
                spaceQuota: 1.0
            }
            horizontalAlignment: HorizontalAlignment.Fill
            verticalAlignment: VerticalAlignment.Fill

        }


        Container {
            id: root
            layout: StackLayout {
            }
            Label {
                text: ListItemData.postText
                horizontalAlignment: HorizontalAlignment.Left
                verticalAlignment: VerticalAlignment.Bottom
            }
            Label {
                text: ListItemData.postDate
                //                    textStyle.fontSize: 5
                horizontalAlignment: HorizontalAlignment.Right
                verticalAlignment: VerticalAlignment.Bottom
            }

            attachedObjects: [
                QTimer {
                    id: timer
                    property int f: 0
                    interval: 5000
                    onTimeout: {
                        progressIndicator.running = false;
                        netpost.imageFetcher();
                        netpost.newsFeedWebService("10");
                    }

                },
                PostHttp {

                    id: netpost
                    onComplete: {
                        progressIndicator.running = false;
                        progressIndicator.visible = false;
                        console.log("dsfdsafs"+netpost.model)
                        timer.stop();
                    }

                    onImageLoaded:{
                        console.log("value is image from cpp jhgsdh " + image)
                        imageviewid.setImageSource(image)
                    }
                    onNewsfeedComplete: {
                        console.log("response from newsfeed is "+info)
                        myListModel.append(info)

                    }
                }

            ]
        }

        onCreationCompleted: {
            // this slot is called when declarative scene is created
            // write post creation initialization here
            console.log("Page - onCreationCompleted()")

            // enable layout to adapt to the device rotation
            // don't forget to enable screen rotation in bar-bescriptor.xml (Application->Orientation->Auto-orient)
            OrientationSupport.supportedDisplayOrientation = SupportedDisplayOrientation.All;

            // populate list view model with the sample data
            timer.start();
            //                myListModel.load("app/native/assets/mydata.json")

        }
        ImageView {
            id: imageviewid
            imageSource: "asset:///images/4.png"
            enabled: true
            loadEffect: ImageViewLoadEffect.FadeZoom

        } 
    }
}
}
Please help me with this.
 解决方案 
So you've defined your slot with QVariant parameter however trying to emit it with QByteArray type which is returned by ImageConverter::encode() call.

Try to change that part of your code to this and give it a go:
QByteArray byteArray = bb::utility::ImageConverter::encode(QUrl(QDir::currentPath() + "/shared/camera/img.png"), imageData, 75);
QVariant image(byteArray);
emit imageLoaded(image);
Also, double check that everywhere where you declare/define this pair of signal/slot you're specified exactly the same parameter notation (ie const QVariant& in case of imageLoaded() signal and so on) 

                        这篇关于在ImageView Blackberry 10中动态设置imageSource的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！


                    
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在ImageView Blackberry 10中动态设置imageSource [英] Dynamically set imageSource in ImageView Blackberry 10

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在ImageView Blackberry 10中动态设置imageSource [英] Dynamically set imageSource in ImageView Blackberry 10

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