1.自定义壁纸

默认壁纸是default_wallpaper，在/frameworks/base/core/res/res,找到drawable-sw720dp-nodpi 、drawable-sw600dp-nodpi、drawable-nodpi的地方中有default_wallpaper.png，然后把自定义的壁纸(custom_wallpaper.png)也拷贝到相应的地方。

2.修改默认壁纸

加载壁纸的类frameworks/base/core/java/android/app/WallpaperManager.java ，custom_wallpaper是自定义壁纸的图片名字。

/**

* Open stream representing the default static image wallpaper.

*

* If the device defines no default wallpaper of the requested kind,

* {@code null} is returned.

*

* @hide

*/

public static InputStream openDefaultWallpaper(Context context, @SetWallpaperFlags int which) {

final String whichProp;

final int defaultResId;

if (which == FLAG_LOCK) {

/* Factory-default lock wallpapers are not yet supported

whichProp = PROP_LOCK_WALLPAPER;

defaultResId = com.android.internal.R.drawable.default_lock_wallpaper;

*/

return null;

} else {

whichProp = PROP_WALLPAPER;

//默认墙纸

// defaultResId = com.android.internal.R.drawable.default_wallpaper;

defaultResId = com.android.internal.R.drawable.custom_wallpaper;

}

final String path = SystemProperties.get(whichProp);

if (!TextUtils.isEmpty(path)) {

final File file = new File(path);

if (file.exists()) {

try {

return new FileInputStream(file);

} catch (IOException e) {

// Ignored, fall back to platform default below

}

}

}

try {

return context.getResources().openRawResource(defaultResId);

} catch (NotFoundException e) {

// no default defined for this device; this is not a failure

}

return null;

3.声明资源

在frameworks中添加资源不是直接把图片拷贝过去就可以的，还需要添加的新资源声明。frameworks/base/core/res/res/values/symbols.xml中添加新添加资源的字段。