从数组列表获取文件名 [英] Get file name from array list
本文介绍了从数组列表获取文件名的处理方法，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
我怎么会去从这个PageAdapter获取文件名，所以我可以用它作为一个字符串，删除图像。
我试过转换viewPager.setCurrentItem（位置）为一个字符串，我试图转换viewPager.getCurrentItem（），我尝试了位图转换为String ......我出出主意，现在轮到你的专家。
我一直在寻找计算器和谷歌3天，找不到任何东西来帮助我这个问题。
任何帮助，您可以提供将大大AP preciated。
FullScreenViewActivity.java
包com.company.imageslider;进口com.company.imageslider.adapter.FullScreenImageAdapter;
进口com.company.imageslider.helper.Utils;
进口android.app.Activity;
进口android.content.Intent;
进口android.os.Bundle;
进口android.support.v4.view.ViewPager;公共类FullScreenViewActivity延伸活动{ 私人utils的utils的;
私人FullScreenImageAdapter适配器;
私人ViewPager viewPager; @覆盖
保护无效的onCreate（捆绑savedInstanceState）{
super.onCreate（savedInstanceState）;
的setContentView（R.layout.activity_fullscreen_view）; viewPager =（ViewPager）findViewById（R.id.pager）; utils的=新utils的（getApplicationContext（））; 意向I = getIntent（）;
INT位置= i.getIntExtra（位置，0）; 适配器=新FullScreenImageAdapter（FullScreenViewActivity.this，
utils.getFilePaths（））; viewPager.setAdapter（适配器）; //首先显示所选图像
viewPager.setCurrentItem（位置）;
}
}
FullScreenImageAdapter.java
包com.company.imageslider.adapter;进口com.company.imageslider.R;
进口com.company.imageslider.helper.TouchImageView;进口的java.util.ArrayList;进口android.app.Activity;
进口android.content.Context;
进口android.graphics.Bitmap;
进口android.graphics.BitmapFactory;
进口android.support.v4.view.PagerAdapter;
进口android.support.v4.view.ViewPager;
进口android.view.LayoutInflater;
进口android.view.View;
进口android.view.ViewGroup;
进口android.widget.Button;
进口android.widget.ImageView;
进口android.widget.RelativeLayout;公共类FullScreenImageAdapter扩展PagerAdapter { 私人活动_activity;
私人的ArrayList＆LT;串GT; _imagePaths;
私人LayoutInflater吹气; //构造
公共FullScreenImageAdapter（活动活动，
ArrayList的＆LT;串GT; imagePaths）{
this._activity =活动;
this._imagePaths = imagePaths;
} @覆盖
公众诠释的getCount（）{
返回this._imagePaths.size（）;
} @覆盖
公共布尔isViewFromObject（查看视图，Object对象）{
返回查看==（（RelativeLayout的）对象）;
} @覆盖
公共对象instantiateItem（ViewGroup中的容器，INT位置）{
TouchImageView imgDisplay;
按钮btnClose; 吹气=（LayoutInflater）_activity
.getSystemService（Context.LAYOUT_INFLATER_SERVICE）;
查看viewLayout = inflater.inflate（R.layout.layout_fullscreen_image，集装箱，
假）; imgDisplay =（TouchImageView）viewLayout.findViewById（R.id.imgDisplay）;
btnClose =（按钮）viewLayout.findViewById（R.id.btnClose）; BitmapFactory.Options选项=新BitmapFactory.Options（）;
options.in preferredConfig = Bitmap.Config.ARGB_8888;
位图位图= BitmapFactory.de codeFILE（_imagePaths.get（位置），选件）;
imgDisplay.setImageBitmap（位图）; //关闭按钮单击事件
btnClose.setOnClickListener（新View.OnClickListener（）{
@覆盖
公共无效的onClick（视图v）{
_activity.finish（）;
}
}）; （（ViewPager）容器）.addView（viewLayout）; 返回viewLayout;
} @覆盖
公共无效destroyItem（ViewGroup中的容器，INT位置，Object对象）{
（（ViewPager）容器）.removeView（（RelativeLayout的）对象）; }}
Utils.java
包com.company.imageslider.helper;进口的java.io.File;
进口的java.util.ArrayList;
进口java.util.Locale中;进口android.app.AlertDialog;
进口android.content.Context;
进口android.graphics.Point;
进口android.view.Display;
进口android.view.WindowManager;
进口android.widget.Toast;公共类的Utils { 私人语境_context; //构造
公共utils的（上下文的背景下）{
this._context =背景;
} / *
*阅读文件从SD卡路径
* /
公众的ArrayList＆LT;串GT; getFilePaths（）{
ArrayList的＆LT;串GT;文件路径=新的ArrayList＆LT;串GT;（）; 文件目录=新的文件（
android.os.Environment.getExternalStorageDirectory（）
+文件分割符+ AppConstant.PHOTO_ALBUM）; //检查目录
如果（directory.isDirectory（））{
//获取文件路径列表
文件[] listFiles = directory.listFiles（）; //检查计数
如果（listFiles.length大于0）{ //通过所有文件循环
的for（int i = 0; I＆LT; listFiles.length;我++）{ //获取文件路径
字符串文件路径= listFiles [I] .getAbsolutePath（）; //检查支持的文件扩展名
如果（IsSupportedFile（文件路径））{
//映像路径添加到数组列表
filePaths.add（文件路径）;
}
}
}其他{
//图像目录是空的
Toast.makeText（
_context，
AppConstant.PHOTO_ALBUM
+是空的，请加载一些图像呢！
Toast.LENGTH_LONG）.show（）;
} }其他{
AlertDialog.Builder警报=新AlertDialog.Builder（_context）;
alert.setTitle（错误！）;
alert.setMessage（AppConstant.PHOTO_ALBUM
+目录路径是无效的，请设置图像的目录名AppConstant.java类！）;
alert.setPositiveButton（OK，NULL）;
alert.show（）;
} 返回文件路径;
} / *
*检查支持的文件扩展名
*
* @Returns布尔
* /
私人布尔IsSupportedFile（字符串文件路径）{
串EXT = filePath.substring（（filePath.lastIndexOf（。）+1），
filePath.length（））; 如果（AppConstant.FILE_EXTN
。载（ext.toLowerCase（Locale.getDefault（））））
返回true;
其他
返回false; } / *
*让屏幕宽度
* /
公众诠释getScreenWidth（）{
INT columnWidth时;
窗口管理WM =（窗口管理器）_context
.getSystemService（Context.WINDOW_SERVICE）;
显示显示= wm.getDefaultDisplay（）; 最后一点点=新点（）;
尝试{
display.getSize（点）;
}赶上（java.lang.NoSuchMethodError忽略）{//旧设备
point.x = display.getWidth（）;
point.y = display.getHeight（）;
}
columnWidth时= point.x;
返回columnWidth时;
}
}
AppConstant.java
包com.company.imageslider.helper;进口java.util.Arrays中;
进口的java.util.List;公共类AppConstant { //的网格视图的列数
公共静态最终诠释NUM_OF_COLUMNS = 3; // GridView的图象填补
公共静态最终诠释GRID_PADDING = 8; //在DP // SD卡图像目录
公共静态最后弦乐PHOTO_ALBUM =NAT; //支持的文件格式
公共静态最后的名单，LT;弦乐＆GT; FILE_EXTN = Arrays.asList（JPG，JPEG，
PNG）;
}
解决方案
您没有得到来自适配器图像路径。您可以从您的数组列表得到它：_imagePaths
使用
字符串路径= _imagePaths.get（mViewPager.getCurrentItem（））;
How would I go about getting the File name from this PageAdapter so I can use it as a string to delete an image.
I tried converting viewPager.setCurrentItem(position) to a string, I tried converting viewPager.getCurrentItem(), I tried converting the Bitmap to a String... I am out of ideas and now turn to you experts.
I have been search stackoverflow and Google for 3 days and can not find anything to help me with this.
Any Help that you can provide would be greatly appreciated.
FullScreenViewActivity.java
package com.company.imageslider;
import com.company.imageslider.adapter.FullScreenImageAdapter;
import com.company.imageslider.helper.Utils;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v4.view.ViewPager;
public class FullScreenViewActivity extends Activity{
private Utils utils;
private FullScreenImageAdapter adapter;
private ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fullscreen_view);
viewPager = (ViewPager) findViewById(R.id.pager);
utils = new Utils(getApplicationContext());
Intent i = getIntent();
int position = i.getIntExtra("position", 0);
adapter = new FullScreenImageAdapter(FullScreenViewActivity.this,
utils.getFilePaths());
viewPager.setAdapter(adapter);
// displaying selected image first
viewPager.setCurrentItem(position);
}
}
FullScreenImageAdapter.java
package com.company.imageslider.adapter;
import com.company.imageslider.R;
import com.company.imageslider.helper.TouchImageView;
import java.util.ArrayList;
import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.RelativeLayout;
public class FullScreenImageAdapter extends PagerAdapter {
private Activity _activity;
private ArrayList<String> _imagePaths;
private LayoutInflater inflater;
// constructor
public FullScreenImageAdapter(Activity activity,
ArrayList<String> imagePaths) {
this._activity = activity;
this._imagePaths = imagePaths;
}
@Override
public int getCount() {
return this._imagePaths.size();
}
@Override
public boolean isViewFromObject(View view, Object object) {
return view == ((RelativeLayout) object);
}
@Override
public Object instantiateItem(ViewGroup container, int position) {
TouchImageView imgDisplay;
Button btnClose;
inflater = (LayoutInflater) _activity
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View viewLayout = inflater.inflate(R.layout.layout_fullscreen_image, container,
false);
imgDisplay = (TouchImageView) viewLayout.findViewById(R.id.imgDisplay);
btnClose = (Button) viewLayout.findViewById(R.id.btnClose);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inPreferredConfig = Bitmap.Config.ARGB_8888;
Bitmap bitmap = BitmapFactory.decodeFile(_imagePaths.get(position), options);
imgDisplay.setImageBitmap(bitmap);
// close button click event
btnClose.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
_activity.finish();
}
});
((ViewPager) container).addView(viewLayout);
return viewLayout;
}
@Override
public void destroyItem(ViewGroup container, int position, Object object) {
((ViewPager) container).removeView((RelativeLayout) object);
}
}
Utils.java
package com.company.imageslider.helper;
import java.io.File;
import java.util.ArrayList;
import java.util.Locale;
import android.app.AlertDialog;
import android.content.Context;
import android.graphics.Point;
import android.view.Display;
import android.view.WindowManager;
import android.widget.Toast;
public class Utils {
private Context _context;
// constructor
public Utils(Context context) {
this._context = context;
}
/*
* Reading file paths from SDCard
*/
public ArrayList<String> getFilePaths() {
ArrayList<String> filePaths = new ArrayList<String>();
File directory = new File(
android.os.Environment.getExternalStorageDirectory()
+ File.separator + AppConstant.PHOTO_ALBUM);
// check for directory
if (directory.isDirectory()) {
// getting list of file paths
File[] listFiles = directory.listFiles();
// Check for count
if (listFiles.length > 0) {
// loop through all files
for (int i = 0; i < listFiles.length; i++) {
// get file path
String filePath = listFiles[i].getAbsolutePath();
// check for supported file extension
if (IsSupportedFile(filePath)) {
// Add image path to array list
filePaths.add(filePath);
}
}
} else {
// image directory is empty
Toast.makeText(
_context,
AppConstant.PHOTO_ALBUM
+ " is empty. Please load some images in it !",
Toast.LENGTH_LONG).show();
}
} else {
AlertDialog.Builder alert = new AlertDialog.Builder(_context);
alert.setTitle("Error!");
alert.setMessage(AppConstant.PHOTO_ALBUM
+ " directory path is not valid! Please set the image directory name AppConstant.java class");
alert.setPositiveButton("OK", null);
alert.show();
}
return filePaths;
}
/*
* Check supported file extensions
*
* @returns boolean
*/
private boolean IsSupportedFile(String filePath) {
String ext = filePath.substring((filePath.lastIndexOf(".") + 1),
filePath.length());
if (AppConstant.FILE_EXTN
.contains(ext.toLowerCase(Locale.getDefault())))
return true;
else
return false;
}
/*
* getting screen width
*/
public int getScreenWidth() {
int columnWidth;
WindowManager wm = (WindowManager) _context
.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
final Point point = new Point();
try {
display.getSize(point);
} catch (java.lang.NoSuchMethodError ignore) { // Older device
point.x = display.getWidth();
point.y = display.getHeight();
}
columnWidth = point.x;
return columnWidth;
}
}
AppConstant.java
package com.company.imageslider.helper;
import java.util.Arrays;
import java.util.List;
public class AppConstant {
// Number of columns of Grid View
public static final int NUM_OF_COLUMNS = 3;
// Gridview image padding
public static final int GRID_PADDING = 8; // in dp
// SD card image directory
public static final String PHOTO_ALBUM = "NAT";
// supported file formats
public static final List<String> FILE_EXTN = Arrays.asList("jpg", "jpeg",
"png");
}
解决方案
You don't get the image path from the adapter. You get it from your array list: _imagePaths
use
String path = _imagePaths.get(mViewPager.getCurrentItem());
这篇关于从数组列表获取文件名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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