如何在运行时权限中获得“不再询问”选项

Question

在我的应用程序中，我创建了一个类名称 Untility，我在其中编写了 READ_EXTERNAL_STORAGE 权限的代码。但问题是当我在应用程序上单击拒绝时，我没有找到警报通知以再次将其设置为允许。最初，我可以选择“不再询问”。一旦我点击它，对话框就会消失。现在运行应用程序后，如果我单击拒绝，我将无法再找到对话框消息以使其再次允许。如何修改我的代码以每次都显示此消息。

我的实用类是

public class Utility {

public static final int MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE = 123;

@TargetApi(Build.VERSION_CODES.M)
public static boolean checkPermission(final Context context) {
    int currentAPIVersion = Build.VERSION.SDK_INT;
    if (currentAPIVersion >= android.os.Build.VERSION_CODES.M) {
        if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
            if (ActivityCompat.shouldShowRequestPermissionRationale((Activity) context, Manifest.permission.READ_EXTERNAL_STORAGE)) {
                Log.v("TAG", "Permission is granted");
            }
            else {
                ActivityCompat.requestPermissions((Activity) context, new String[]{Manifest.permission.READ_EXTERNAL_STORAGE}, MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE);
            }
            return false;
        } else {
            return true;
        }
    } else {
        return true;
    }
 }

我在这里调用的另一个类是 Utility 类是

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case Utility.MY_PERMISSIONS_REQUEST_READ_EXTERNAL_STORAGE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                if(userChoosenTask.equals("Take Photo"))
                    cameraIntent();
                else if(userChoosenTask.equals("Choose from Library"))
                    galleryIntent();

                    //do something here
            } else {
                //code for deny
                Toast.makeText(DetailMyColleague.this, "Permission Denied", Toast.LENGTH_SHORT).show();
            }
            break;
    }
}
private void selectImage() {
    final CharSequence[] items = { "Take Photo", "Choose from Library",
            "Cancel" };

    AlertDialog.Builder builder = new AlertDialog.Builder(DetailMyColleague.this);
    builder.setTitle("Add Photo!");
    builder.setItems(items, new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int item) {
            boolean result=Utility.checkPermission(DetailMyColleague.this);

            if (items[item].equals("Take Photo")) {
                userChoosenTask ="Take Photo";
                if(result)
                    cameraIntent();

            } else if (items[item].equals("Choose from Library")) {
                userChoosenTask ="Choose from Library";
                if(result)
                    galleryIntent();

            } else if (items[item].equals("Cancel")) {
                dialog.dismiss();
            }
        }
    });
    builder.show();
}
private void galleryIntent()
{
    Intent intent = new Intent();
    intent.setType("image/*");
    intent.setAction(Intent.ACTION_GET_CONTENT);//
    startActivityForResult(Intent.createChooser(intent, "Select File"),SELECT_FILE);
}
private void cameraIntent()
{
    Intent intent = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
    startActivityForResult(intent, REQUEST_CAMERA);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
    super.onActivityResult(requestCode, resultCode, data);

    if (resultCode == Activity.RESULT_OK) {
        if (requestCode == SELECT_FILE)
            onSelectFromGalleryResult(data);
        else if (requestCode == REQUEST_CAMERA)
            onCaptureImageResult(data);
    }
}

private void onCaptureImageResult(Intent data) {
    Bitmap thumbnail = (Bitmap) data.getExtras().get("data");
    ByteArrayOutputStream bytes = new ByteArrayOutputStream();
    thumbnail.compress(Bitmap.CompressFormat.JPEG, 90, bytes);

    File destination = new File(Environment.getExternalStorageDirectory(),
            System.currentTimeMillis() + ".jpg");

    FileOutputStream fo;
    try {
        destination.createNewFile();
        fo = new FileOutputStream(destination);
        fo.write(bytes.toByteArray());
        fo.close();
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    } catch (IOException e) {
        e.printStackTrace();
    }

    profilePic.setImageBitmap(thumbnail);
}
@SuppressWarnings("deprecation")
private void onSelectFromGalleryResult(Intent data) {

    Bitmap bm=null;
    if (data != null) {
        try {
            bm = MediaStore.Images.Media.getBitmap(getApplicationContext().getContentResolver(), data.getData());
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    profilePic.setImageBitmap(bm);
}

Answer 1

如何修改我的代码以每次都显示这条消息。

你不能。如果用户选中“不再询问”，则用户授予权限的唯一方法是通过“设置”应用。一旦用户选中“不再询问”并拒绝该权限，您就无法显示该权限组中任何权限的权限对话框。

Answer 2

一旦他们说“不再询问”，您就不能显示相同的请求消息，但您可以检查权限，如果被拒绝，则显示一个自定义对话框，将他们定向到设置页面：

startActivityForResult(new Intent(android.provider.Settings.ACTION_SETTINGS), 0);

如果您的权限检查失败：

if (ContextCompat.checkSelfPermission(context, Manifest.permission.READ_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED) {
    // show a dialog
    new AlertDialog.Builder(this).setMessage("You need to enable permissions to use this feature").setPositiveButton("Go to settings", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // navigate to settings
            startActivityForResult(new Intent(android.provider.Settings.ACTION_SETTINGS), 0);
        }
    }).setNegativeButton("Go back", new DialogInterface.OnClickListener() {
        @Override
        public void onClick(DialogInterface dialog, int which) {
            // leave?
            MyActivity.this.onBackPressed();
        }
    }).show();
}

Answer 3

“不再询问”复选框仅在每个权限代码多次拒绝后才可见。如果您选中“不再询问”并单击拒绝，则权限将被自动拒绝。如果您想再次选择，请进入您的应用程序的“应用程序信息”页面并清除您的应用程序的数据存储。现在，如果您返回应用程序并再次请求权限。然后，将显示默认权限对话框。 您可以查看文档here。

Answer 4

当权限已经被“拒绝”并且方法 shouldShowRequestPermissionRationale() 返回 false 时，可以计算出“不再显示”状态

当系统无法显示系统对话框（用户选择“不再显示”的“接受”）时，此方法可用作向用户显示附加信息的可能性

Deny             >> shouldShowRequestPermissionRationale(permission) -> true
Don't ask again  >> shouldShowRequestPermissionRationale(permission) -> false
Accept           >> shouldShowRequestPermissionRationale(permission) -> false

如果在您请求的所有权限都被拒绝并且其中至少一个权限被“不再询问”复选框拒绝时您无法提供任何操作 - 最好的方法是将用户导航到系统中的应用程序设置.

这是“接受”/“拒绝”/“不再询问”工作流程的解决方案。 这里还有一个 Jetpack Activity Result API 的示例。 （请求多个权限并导航到另一个活动并返回）

代码注释：

• 请求权限（使用活动结果 API）还包含检查系统内的“已授予”权限状态，对于您请求的每个权限，您只会收到真/假结果
• actionPermXXX 是您可以在授予权限后向系统提供您的操作的地方（例如开始位置观察和/或从外部存储中获取图像等）
• “不再显示”权限状态可以通过在应用程序的设置（设置 > 应用程序 > 'Your_app' > 权限）中手动更改此权限来重置

PS。代码并不完美，但很好理解

片段

class Fragment_ActiityResultAPI_RequestMultiplePermissions : Fragment(){

    val actionPermLocation = {
        tvPerm1.text = "GRANTED";
        tvPerm1.setTextColor(Color.GREEN)
    }
    val actionPermReadExt = {
        tvPerm2.text = "GRANTED";
        tvPerm2.setTextColor(Color.GREEN)
    }
    val permissionsAll = mutableMapOf(
        Manifest.permission.ACCESS_FINE_LOCATION  to actionPermLocation,
        Manifest.permission.READ_EXTERNAL_STORAGE to actionPermReadExt,
    )
    private val arcRequestPermissions = registerForActivityResult(RequestMultiplePermissions()){ perms ->
        perms.entries.forEach {
            if(it.value){
                permissionsAll[it.key]?.invoke()
            }
        }
    }
    private val arcNavigateToSettings = registerForActivityResult(StartSettingsActivityContract()) {
        arcRequestPermissions.launch(permissionsAll.keys.toTypedArray())
    }
    override fun onCreateView(
    inflater: LayoutInflater,
    container: ViewGroup?,
    savedInstanceState: Bundle?
): View? {
        return inflater.inflate(R.layout.fragment_layout, container, false)
    }
    override fun onViewCreated(layoutView: View, savedInstanceState: Bundle?) {
        super.onViewCreated(layoutView, savedInstanceState)
        // CHECK PERMISSIONS AT FRAGMENT START
        arcRequestPermissions.launch(permissionsAll.keys.toTypedArray())
        btn.setOnClickListener {
            // CHECK PERMISSION AT BUTTON CLICK
            processPermission()
        }
    }
    private fun processPermission() {
        var atLeastOnePermDenied         = false
        var atLeastOnePermAsDontAskAgain = false
        permissionsAll.keys.toTypedArray().forEach {
            atLeastOnePermDenied         = atLeastOnePermDenied         || checkPermDenied(it)
            atLeastOnePermAsDontAskAgain = atLeastOnePermAsDontAskAgain || checkPermDontAskAgain(it)
        }
        if(atLeastOnePermAsDontAskAgain){
            showAlertNavigateToAppSettings()
            return
        }
        if(atLeastOnePermDenied){
            arcRequestPermissions.launch(permissionsAll.keys.toTypedArray())
            return
        }
        Utils.toast(requireContext(), ">>>  Execute your target action!!  <<<")
    }
    private fun checkPermDenied(perm: String): Boolean {
        return (ActivityCompat.checkSelfPermission(requireContext(), perm)
                ==
                PackageManager.PERMISSION_DENIED)
    }
    private fun checkPermDontAskAgain(perm: String): Boolean {
        return checkPermDenied(perm) && !shouldShowRequestPermissionRationale(perm)
    }
    private fun showAlertNavigateToAppSettings() {
        val builder = AlertDialog.Builder(requireContext())
        builder.setMessage("You have to grant permissions for action")
        builder.setPositiveButton("Go to Settings") { dialog, which -> // Do nothing but close the dialog
            arcNavigateToSettings.launch(1)
        }
        builder.setNegativeButton("Cancel") { dialog, which -> // Do nothing
            dialog.dismiss()
        }
        val alert = builder.create()
        alert.show()
    }
    class StartSettingsActivityContract : ActivityResultContract<Int, String?>() {
        override fun createIntent(context: Context, input: Int): Intent {
            return Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS).apply {
                val uri = Uri.fromParts("package", context.packageName, null)
                this.data = uri
            }
        }
        override fun parseResult(resultCode: Int, intent: Intent?): String? {
            return ""
        }
    }
}

布局

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:background="@android:color/white">

    <LinearLayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="vertical">

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="LOCATION: "
                android:textColor="@android:color/darker_gray"/>

            <TextView
                android:id="@+id/tvPerm1"
                android:layout_width="100dp"
                android:layout_height="wrap_content"
                android:text="Denied"
                android:textColor="@android:color/darker_gray"/>

        </TableRow>

        <TableRow
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <TextView
                android:layout_width="150dp"
                android:layout_height="wrap_content"
                android:text="READ_STORAGE: "
                android:textColor="@android:color/darker_gray"/>

            <TextView
                android:id="@+id/tvPerm2"
                android:layout_width="100dp"
                android:layout_height="wrap_content"
                android:text="Denied"
                android:textColor="@android:color/darker_gray"/>

        </TableRow>

    </LinearLayout>

    <FrameLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        <Button
            android:id="@+id/btn"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_marginTop="50dp"
            android:layout_gravity="center_horizontal"
            android:text="Launch a Camera"/>
    </FrameLayout>

</LinearLayout>

build.gradle

implementation 'androidx.activity:activity-ktx:1.2.1'
implementation 'androidx.fragment:fragment:1.3.0-alpha05'