java - 如何以编程方式将图像设置为墙纸？

Question

我一直在开发需要将图像设置为墙纸的应用程序。

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());
    }

我还添加了以下权限:

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

但它不起作用；该文件存在于 SD 卡上。我哪里做错了？

Answer 1

如果您的图像很大，可能会耗尽内存。您可以通过阅读 Logcat 日志来确定它。如果是这种情况，请尝试通过如下方式将图片调整为适合设备大小:

    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);
    }