Android 将墙纸图像设置为锁屏背景技巧

**此代码将图像置于屏幕顶部，但隐藏所有锁屏内容，并禁用锁屏触摸 **

要求 绘制的图像应显示为锁屏的背景 锁屏内容应可见 通知托盘不应受到阻碍 应启用锁屏触摸

import android.app.Service;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.graphics.PixelFormat;
import android.os.IBinder;
import android.view.WindowManager;
import android.widget.ImageView;


public class LockScreenImageService extends Service {

    private BroadcastReceiver mReceiver;
    private boolean isShowing = false;

    @Override
    public IBinder onBind(Intent intent) {
        // TODO Auto-generated method stub
        return null;
    }

    private WindowManager windowManager;
    private ImageView imageView;
    WindowManager.LayoutParams params;

    @Override
    public void onCreate() {
        super.onCreate();

        windowManager = (WindowManager)getSystemService(WINDOW_SERVICE);

        imageView = new ImageView(this);
      imageView.setBackgroundColor(this.getResources().getColor(R.color.colorAccent));
       imageView.setImageDrawable(this.getResources().getDrawable(R.drawable.ic_img));

        //set parameters for the imageView
        params = new WindowManager.LayoutParams(
                WindowManager.LayoutParams.MATCH_PARENT,
                WindowManager.LayoutParams.MATCH_PARENT,
                WindowManager.LayoutParams.TYPE_SYSTEM_ERROR,
                WindowManager.LayoutParams.FLAG_SHOW_WALLPAPER,
                PixelFormat.TRANSPARENT);


        //Register receiver for determining screen off and if user
        // is present
        mReceiver = new LockScreenStateReceiver();
        IntentFilter filter = new IntentFilter(Intent.ACTION_SCREEN_OFF);
        filter.addAction(Intent.ACTION_USER_PRESENT);

        registerReceiver(mReceiver, filter);
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        return START_STICKY;
    }

    public class LockScreenStateReceiver extends BroadcastReceiver {
        @Override
        public void onReceive(Context context, Intent intent) {
            if (intent.getAction().equals(Intent.ACTION_SCREEN_OFF)) {
                //if screen is turn off show the imageView
                if (!isShowing) {
               //  windowManager.addView(imageView, params);
                    isShowing = true;
                }
            }

            else if(intent.getAction().equals(Intent.ACTION_USER_PRESENT)) {
                //Handle resuming events if user is present/screen is unlocked remove the imageView immediately
                if (isShowing) {
                    windowManager.removeViewImmediate(imageView);
                    isShowing = false;
                }
            }
        }
    }

    @Override
    public void onDestroy() {
        //unregister receiver when the service is destroy
        if (mReceiver != null) {
            unregisterReceiver(mReceiver);
        }

        //remove view if it is showing and the service is destroy
        if (isShowing) {
            windowManager.removeViewImmediate(imageView);
            isShowing = false;
        }
        super.onDestroy();
    }

}