如何以编程方式将图像设置为壁纸？

Question

我一直在开发需要设置图像作为壁纸的应用程序。

代码：

WallpaperManager m=WallpaperManager.getInstance(this); 

String s=Environment.getExternalStorageDirectory().getAbsolutePath()+"/1.jpg"; 
File f=new File(s); 
Log.e("exist", String.valueOf(f.exists())); 
try { 
     InputStream is=new BufferedInputStream(new FileInputStream(s)); 
     m.setBitmap(BitmapFactory.decodeFile(s)); 

    } catch (FileNotFoundException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
     Log.e("File", e.getMessage()); 
    } catch (IOException e) { 
     // TODO Auto-generated catch block 
     e.printStackTrace(); 
     Log.e("IO", e.getMessage()); 
    } 

而且我已经添加了以下权限：

<uses-permission android:name="android.permission.SET_WALLPAPER" /> 

但它不工作;该文件存在于SD卡上。我在哪里犯了一个错误？

Answer 1

File f = new File(Environment.getExternalStorageDirectory(), "1.jpg"); 
String path = f.getAbsolutePath(); 
File f1 = new File(path); 

if(f1.exists()) { 
    Bitmap bmp = BitmapFactory.decodeFile(path); 
    BitmapDrawable bitmapDrawable = new BitmapDrawable(bmp); 
    WallpaperManager m=WallpaperManager.getInstance(this); 

    try { 
     m.setBitmap(bmp); 
    } catch (IOException e) { 
     e.printStackTrace(); 
    } 
} 

打开AndroidManifest.xml文件，并添加权限如..

<uses-permission android:name="android.permission.SET_WALLPAPER" /> 

试试这个，让我知道发生什么事..

Answer 2

可能的话，你耗尽内存，如果你的形象大。你可以通过阅读Logcat日志来确定它。如果是这种情况，尝试调整您的图片到设备的大小有点像这样：

DisplayMetrics displayMetrics = new DisplayMetrics(); 
    getWindowManager().getDefaultDisplay().getMetrics(displayMetrics); 
    int height = displayMetrics.heightPixels; 
    int width = displayMetrics.widthPixels << 1; // best wallpaper width is twice screen width 

    // First decode with inJustDecodeBounds=true to check dimensions 
    final BitmapFactory.Options options = new BitmapFactory.Options(); 
    options.inJustDecodeBounds = true; 
    BitmapFactory.decodeFile(path, options); 

    // Calculate inSampleSize 
    options.inSampleSize = calculateInSampleSize(options, width, height); 

    // Decode bitmap with inSampleSize set 
    options.inJustDecodeBounds = false; 
    Bitmap decodedSampleBitmap = BitmapFactory.decodeFile(path, options); 

    WallpaperManager wm = WallpaperManager.getInstance(this); 
    try { 
     wm.setBitmap(decodedSampleBitmap); 
    } catch (IOException e) { 
     Log.e(TAG, "Cannot set image as wallpaper", e); 
    }