Android M - 未能检查运行时权限

Question

我刚刚开始在 Android M 上使用运行时权限。我在 AndroidManifest.xml 中声明了 CAMERA、READ_EXTERNAL_STORAGE 和 WRITE_EXTERNAL_STORAGE

问题是如果用户转到设置并明确关闭如下权限，我无法检查我的应用是否启用了相机或存储权限

我使用这个 sn-p 来检查我的应用是否有特定权限：

public static boolean hasPermission(Context c, String permission) {
    if (Build.VERSION.SDK_INT >= 23) {
        return ContextCompat.checkSelfPermission(c, permission) == PackageManager.PERMISSION_GRANTED;
    }
    return true;
}

令人惊讶的是，即使我在“设置”中将它们关闭，每次检查相机和存储权限都会返回 true（已授予）。

我的targetSdkVersion 23 岁

这是 Google 提供的预期行为吗？我环顾网络，仍然找不到任何文档说明处理显式调用的权限。

Answer 1

再次检查 onRestart() 中的权限。

@TargetApi(Build.VERSION_CODES.M)
    @Override
    protected void onRestart() {
        super.onRestart();
        checkForPermission();
    }


@TargetApi(Build.VERSION_CODES.M)
    private void checkForPermission() {
        int permissionCheck = checkSelfPermission(Manifest.permission.READ_CONTACTS);
        if (permissionCheck == PackageManager.PERMISSION_GRANTED) {
            Log.d(TAG, "Granted");
        } else {
            if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this, Manifest.permission.READ_CONTACTS)) {
                Log.d(TAG, "Contacts Permission Required!!");
                createSnackbar("Contacts Permission Required!!", "Try Again");
            }
            ActivityCompat.
                    requestPermissions(MainActivity.this, new String[]{Manifest.permission.READ_CONTACTS}, REQUEST_CONTACT);

        }
    }

查看此链接以获取更多信息： https://github.com/sagarjogadia28/PermissionSample/

Answer 2

您必须更改 targetSDKVersion 因为

您应该为低于 23 的任何 targetSdkVersion 获得 PERMISSION_GRANTED，即使用户在“设置”中关闭了该权限组。建议您彻底卸载应用，将 targetSdkVersion 设置为 23，然后再试一次。

你可以查看这个link

Answer 3

你需要做不同的事情。

首先，请求允许您尝试执行的操作。示例相机：

//This is a class variable
private final static int MY_PERMISSIONS_REQUEST_CAMERA = 1;

...

// before use camera:
// check permissions for CAMERA
if (ContextCompat.checkSelfPermission(ActivityName.this,
        Manifest.permission.CAMERA)
        != PackageManager.PERMISSION_GRANTED) {

    //request permission
    ActivityCompat.requestPermissions(ActivityName.this,
            new String[]{Manifest.permission.CAMERA},
            MY_PERMISSIONS_REQUEST_CAMERA);

} else {
    //permissions granted, do wahtever with camera
    functionToHandleCamera();
}

然后您需要处理用户响应：允许或拒绝。所以重写 onRequestPermissionsResult 方法

@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) {
                //permissions granted, do wahtever with camera
                functionToHandleCamera();

            } else {
                // permission denied
                Toast msg = Toast.makeText(this, "PERMISSIONS NEEDED", Toast.LENGTH_LONG);
                msg.setGravity(Gravity.CENTER, 0, 0);
                msg.show();
            }
            return;
        }

    }
}

更多信息： https://developer.android.com/training/permissions/requesting.html

编辑：如果你只想检查权限是否被授予，你只需要我写的代码的第一部分。

Answer 4

将此添加到您的onCreate 活动方法中：-

if (ContextCompat.checkSelfPermission(this,
            Manifest.permission.ACCESS_FINE_LOCATION)
            != PackageManager.PERMISSION_GRANTED) {

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

            // Show an expanation 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 {

            ActivityCompat.requestPermissions(this,
                    new String[]{Manifest.permission.ACCESS_FINE_LOCATION},
                    0);

        }
    }

和override这个方法：-

@Override

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

                // permission was granted, yay! Do the
                // contacts-related task you need to do.

            } 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
    }
}