app.exec()不能调用其他方法(static lib Qt) [英] app.exec() cannot call other method (static lib Qt)
问题描述
我创建一个静态库管理器Qt。我需要通过调用一些方法,改变图片的位置。问题是,app.exec()块完全的过程。你知道如何做吗?
I create a static librairy Qt. I need by calling some method, to change the position of a picture. The problem is that the "app.exec()" block completly the process. Do you know how to do it ?
非常感谢。
这里是我的头文件lib
Here is my header file of the lib
int init(int argc, char *argv[], int width, int height);
void changePos (int x, int y);
void destroyPic();
我的init是:
QWidget * window(0);
QLabel * pic(0);
and my init is : QWidget* window(0); QLabel* pic(0);
int init(int argc, char *argv[], int width, int height) {
// initialize resources, if needed
Q_INIT_RESOURCE(target);
QApplication app(argc, argv);
window = new QWidget();
window->setWindowTitle("Test");
window->setFixedSize(width, height);
// create and show your widgets here
pic = new QLabel(window);
QPixmap pixmap(QString(":/res/pic.png"));
pic->setPixmap(pixmap);
pic->move(100,100);
pic->setVisible(true);
window->show();
app.exec();
return 0;
}
问题是我无法在我的主代码中调用lib)方法changePos或者destroy因为app.exec()阻塞进程...如何做呢?
the problem is i can't called in my main code (which use this lib) the method changePos or destroy because the app.exec() block the process... how to do it ?
非常感谢!
推荐答案
您需要在单独的QThread中启动QApplication。这在下面的代码中显示。我还没有得到它的工作在OS X,但我相信它应该是可行的。我需要先获得一个调试生成为OS X,然后我会看到什么结果。它经过测试可以在Windows上工作,也可能在X11上工作。 Objective C代码只用于mac,它可能是必需的,但还不够。
You need to start QApplication in a separate QThread. This is shown in the code below. I haven't gotten it working on OS X yet, but I believe it should be doable. I need first to get a debug build made for OS X, then I'll see what's up. It's tested to work on Windows, and will probably work on X11 too. The Objective C code is for mac only, it's probably required but not sufficient yet.
它是一个完整的可运行的应用程序,对于一个库,你会删除 main()
函数并调用init,changePos并直接完成。
It is an entire runnable application, for a library you'd remove the main()
function and call init, changePos and finish directly as appropriate.
#applib.pro
QT += core gui
TARGET = applib
TEMPLATE = app
!x11:!embedded:!qpa:mac {
LIBS_PRIVATE += -framework Cocoa -lz
OBJECTIVE_SOURCES += thread.mm
}
SOURCES += main.cpp
//main.cpp
#include <cstdlib>
#include <QtCore/QThread>
#include <QtCore/QMutex>
#include <QtCore/QMutexLocker>
#include <QtCore/QWaitCondition>
#include <QtCore/QEvent>
#include <QtGui/QLabel>
#include <QtGui/QApplication>
//
// API
//
extern "C" {
void init(int argc, char ** argv);
void changePos(int x, int y);
void finish();
}
// demonstration code, remove from the library
int main(int argc, char ** argv)
{
class Helper : private QThread {
public:
static void msleep(unsigned long ms) {
QThread::msleep(ms);
}
};
init(argc, argv);
Helper::msleep(2000);
changePos(0, 0);
Helper::msleep(2000);
finish();
}
//
// IMPLEMENTATION
//
struct PosEvent : public QEvent
{
PosEvent(int x_, int y_) : QEvent(t()),
x(x_), y(y_) {}
const int x, y;
static QEvent::Type t() { return (QEvent::Type)(QEvent::User + 0); }
};
class Widget : public QLabel
{
public:
Widget() : QLabel("Hello!") {}
protected:
void customEvent(QEvent * ev) {
if (ev->type() == PosEvent::t()) {
PosEvent * pev = static_cast<PosEvent*>(ev);
move(pev->x, pev->y);
}
}
};
class QCoreApplicationPrivate {
public:
static QThread * theMainThread;
};
extern "C++" { Qt::HANDLE qt_application_thread_id; }
class AppThread : public QThread
{
public:
AppThread(int& argc_, char ** argv_) {
Q_ASSERT(!instance);
instance = this;
QMutexLocker lock(&argMutex);
argc = &argc_;
argv = argv_;
start();
wc.wait(&argMutex);
}
static void changePos(int x, int y) {
QCoreApplication::postEvent(instance->widget, new PosEvent(x,y));
}
static void finish() {
instance->app->exit();
instance->wait();
delete instance;
}
protected:
void run() {
int i = 0;
#ifdef Q_OS_UNIX
//qDebug("%p", qt_application_thread_id);
QCoreApplicationPrivate::theMainThread = QThread::currentThread();
#endif
QApplication a(i, 0);
app = &a;
wc.wakeAll();
Widget w;
widget = &w;
w.show();
rc = a.exec();
}
private:
static AppThread * instance;
QCoreApplication * app;
QObject * widget;
QMutex argMutex;
QWaitCondition wc;
int* argc;
char** argv;
int rc;
};
AppThread * AppThread::instance = 0;
bool multiThreader();
#ifndef Q_OS_MAC
bool multiThreader() { return true; }
#endif
extern "C" void init(int argc, char ** argv) {
multiThreader();
#ifdef Q_OS_MAC
qDebug("DYLD_IMAGE_SUFFIX=%s", getenv("DYLD_IMAGE_SUFFIX"));
#endif
new AppThread(argc, argv);
}
extern "C" void changePos(int x, int y) { AppThread::changePos(x, y); }
extern "C" void finish() { AppThread::finish(); }
//thread.mm
#import <Foundation/Foundation.h>
@interface DeadThread : NSObject { ;; }
+ (void)enterMultiThreadedMode;
+ (void)emptyThreadMethod:(id)obj;
@end
@implementation DeadThread
+ (void)enterMultiThreadedMode {
NSAutoreleasePool *pool = [[NSAutoreleasePool alloc] init];
[NSThread detachNewThreadSelector:@selector(emptyThreadMethod:)
toTarget:[DeadThread class] withObject:nil];
[pool release];
}
+ (void)emptyThreadMethod:(id)obj { (void)obj; }
@end
bool multiThreader()
{
[DeadThread enterMultiThreadedMode];
return [NSThread isMultiThreaded];
}
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