Question

我设计了一个应用程序，要求允许启动时使用相机。但是，对于Android 6及更高版本，该应用程序崩溃为

allow the access to camera Camera.open() return null

我已将camera.setDisplayOrentaion(90);设置为返回Null。

Answer 1

在用户授予权限之前，您不应初始化相机，并且onRequestPermissionsResult会调用PERMISSION_GRANTED Activity。有关如何在应用中正确处理运行时权限的详细信息，请参阅this。

Answer 2

首先检查是否允许

int permissionCheck = ContextCompat.checkSelfPermission(thisActivity,
        Manifest.permission.CAMERA);

如果授予了权限，permission check = PackageManager.PERMISSION_GRANTED或反之亦然PERMISSION_DENIED。

然后你可以要求它。

if (ContextCompat.checkSelfPermission(thisActivity,
                Manifest.permission.CAMERA)
        != PackageManager.PERMISSION_GRANTED) {

    // Should we show an explanation?
    if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,
            Manifest.permission.CAMERA)) {

        // Show an explanation to the user *asynchronously* -- don't block
        // this thread waiting for the user's response! After the user
        // sees the explanation, try again to request the permission.

    } else {

        // No explanation needed, we can request the permission.

        ActivityCompat.requestPermissions(thisActivity,
                new String[]{Manifest.permission.CAMERA},
                MY_PERMISSIONS_REQUEST_CAMERA);

        // MY_PERMISSIONS_REQUEST_CAMRA is an
        // app-defined int constant. The callback method gets the
        // result of the request.
    }
}

然后你需要处理响应：

@Override
public void onRequestPermissionsResult(int requestCode,
        String permissions[], int[] grantResults) {
    switch (requestCode) {
        case MY_PERMISSIONS_REQUEST_CAMERA: {
            // If request is cancelled, the result arrays are empty.
            if (grantResults.length > 0
                && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                // permission was granted, yay! Open
                // camera, take photo.

            } else {

                // permission denied, boo! Disable the
                // functionality that depends on this permission.
            }
            return;
        }

        // other 'case' lines to check for other
        // permissions this app might request
    }
}

应用程序在Android 6及更高版本上崩溃以获取相机启动权限

2 个答案: