如何获取android锁屏壁纸? [英] How to get android lock screen wallpaper?

问题描述

我使用以下代码在android 8.1手机上检索android锁屏壁纸:

I use the code below to retrieve the android lock screen wallpaper on an android 8.1 phone:

WallpaperManager manager = WallpaperManager.getInstance(getActivity());
ParcelFileDescriptor pfd = manager.getWallpaperFile(WallpaperManager.FLAG_LOCK);
if (pfd == null) // pfd is always null for FLAG_LOCK, why?
    return;
Bitmap lockScreenWallpaper = BitmapFactory.decodeFileDescriptor(pfd.getFileDescriptor());
// ...

我已授予 READ_EXTERNAL_STORAGE 权限，并预先设置了锁屏壁纸.

I have granted the READ_EXTERNAL_STORAGE permission and set a lock screen wallpaper beforehand.

我在真实的手机上运行演示，发现 pfd 对于 FLAG_LOCK 始终为空，因此无法获得锁屏墙纸.请帮助解决问题，谢谢.

I run the demo on a real phone, and found the pfd is always null for FLAG_LOCK, so I cannot get the lock screen wallpaper. Please help fix the problem, thanks.

推荐答案

我自己找到了答案，希望它可以帮助其他有相同问题的人.

I find the answer myself, I hope it can help others with the same question.

getWallpaperFile 的官方文档说:如果没有为给定的用户配置任何特定于锁的墙纸，则此方法在请求FLAG_LOCK时将返回null，而不是返回系统墙纸的图像文件.

描述含糊不清，至少不够清晰，这是什么意思?如果您同时将照片设置为锁定屏幕和主屏幕墙纸，则两者共享相同的文件，然后调用

The description is vague, at least not clear enough, what does it mean? If you set a photo as both lock screen and home screen wallpaper, the two share the same file, then by calling

ParcelFileDescriptor pfd = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_LOCK);

pfd 始终为空，那么您应该通过以下方式获取锁屏墙纸:

pfd will always be null, then you should get the lock screen wallpaper this way:

if (pfd == null)
    pfd = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_SYSTEM);

您将获得非空的 pfd .这是未配置锁特定墙纸的情况.

you will get the non-null pfd. This is the case no lock-specific wallpaper has been configured.

相反，如果您直接将照片设置为锁屏墙纸，则已经配置了锁定特定的墙纸， wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_SYSTEM)将返回一个非空值.

On the contrary, lock-specific wallpaper has been configured if you set a photo as lock screen wallpaper directly, wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_SYSTEM) will return a non-null value.

这是我用来检索锁屏墙纸的代码:

So this is the code I use to retrieve the lock screen wallpaper:

/**
 * please check permission outside
 * @return Bitmap or Drawable
 */
public static Object getLockScreenWallpaper(Context context)
{
    WallpaperManager wallpaperManager = WallpaperManager.getInstance(context);
    if (Build.VERSION.SDK_INT >= 24)
    {
        ParcelFileDescriptor pfd = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_LOCK);
        if (pfd == null)
            pfd = wallpaperManager.getWallpaperFile(WallpaperManager.FLAG_SYSTEM);
        if (pfd != null)
        {
            final Bitmap result = BitmapFactory.decodeFileDescriptor(pfd.getFileDescriptor());

            try
            {
                pfd.close();
            }
            catch (Exception e)
            {
                e.printStackTrace();
            }

            return result;
        }
    }
    return wallpaperManager.getDrawable();
}

别忘了在清单文件中添加 READ_EXTERNAL_STORAGE 并将其授予外部.

Don't forget to add READ_EXTERNAL_STORAGE in the manifest file and grant it outside.

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