问 validateClientPermissionsLocked:来电者“包”不能从背景中打开相机"1“

Camera.CameraInfo cameraInfo = new Camera.CameraInfo();
cameraCount = Camera.getNumberOfCameras();
for (int camIdx = 0; camIdx < cameraCount; camIdx++) {
    Camera.getCameraInfo(camIdx, cameraInfo);
    if (cameraInfo.facing == Camera.CameraInfo.CAMERA_FACING_FRONT) {
        myCamera = Camera.open(camIdx);
}

W/CameraBase: An error occurred while connecting to camera 1: Status(-8): '6: validateClientPermissionsLocked:915: Caller "packagename" (PID 10152, UID 32606) cannot open camera "1" from background'
W/System.err: java.lang.RuntimeException: Fail to connect to camera service
W/System.err:     at android.hardware.Camera.<init>(Camera.java:546)
W/System.err:     at android.hardware.Camera.open(Camera.java:392)
W/System.err:     at com.tracking_smartphone.TakePictureActivity.takePictureNoPreview(TakePictureActivity.java:77)
W/System.err:     at com.tracking_smartphone.TakePictureActivity.onCreate(TakePictureActivity.java:46)
W/System.err:     at android.app.Activity.performCreate(Activity.java:7144)
W/System.err:     at android.app.Activity.performCreate(Activity.java:7135)
W/System.err:     at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
W/System.err:     at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2894)
W/System.err:     at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3049)
W/System.err:     at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
W/System.err:     at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
W/System.err:     at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
W/System.err:     at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1809)
W/System.err:     at android.os.Handler.dispatchMessage(Handler.java:106)
W/System.err:     at android.os.Looper.loop(Looper.java:193)
W/System.err:     at android.app.ActivityThread.main(ActivityThread.java:6680)