Question

我试图让我的应用在用户点击请求权限按钮（btRequest）时能够请求权限。构建应用程序时我没有遇到任何问题，但在手机上运行时我的应用程序停止了。检查权限请求工作得很好，因为当我点击btCheck我能够得到一个结果。尝试请求权限可能会出现什么问题？

Logcat file

private Context context;
private Activity activity;
private static final int PERMISSION_REQUEST_CODE = 1;
private View view;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
    setSupportActionBar(toolbar);


    Button btRequest = (Button)findViewById(R.id.btRequest);
    Button btCheck = (Button)findViewById(R.id.btCheck);
    btRequest.setOnClickListener(this);
    btCheck.setOnClickListener(this);

}

@Override
public void onClick(View v) {

    view = v;

    int id = v.getId();
    switch (id){
        case R.id.btCheck:
            if (checkPermission()) {

                Snackbar.make(view,"Permission already granted.",Snackbar.LENGTH_LONG).show();

            } else {

                Snackbar.make(view,"Please request permission.",Snackbar.LENGTH_LONG).show();
            }
            break;
        case R.id.btRequest:
            if (!checkPermission()) {

                requestPermission();

            } else {

                Snackbar.make(view,"Permission already granted.",Snackbar.LENGTH_LONG).show();

            }
            break;
    }
}

private boolean checkPermission(){
    int result = ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION);
    if (result == PackageManager.PERMISSION_GRANTED){

        return true;

    } else {

        return false;

    }
}

private void requestPermission(){

    if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,Manifest.permission.ACCESS_FINE_LOCATION)){

        Toast.makeText(context,"GPS permission allows us to access location data." +
                " Please allow in App Settings for additional functionality.", Toast.LENGTH_LONG).show();

    } else {

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

@Override
public void onRequestPermissionsResult(int requestCode, String permissions[], int[] grantResults) {
    switch (requestCode) {
        case PERMISSION_REQUEST_CODE:
            if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {

                Snackbar.make(view,"Permission Granted, Now you can access location data.",Snackbar.LENGTH_LONG).show();

            } else {

                Snackbar.make(view,"Permission Denied, You cannot access location data.",Snackbar.LENGTH_LONG).show();

            }
            break;
    }
}
}

Answer 1

检查构建操作系统版本（无需询问操作系统版本的权限＆lt; 23）

步骤1 :(检查操作系统版本）

 if(android.os.Build.VERSION.SDK_INT >= 23) 
    {
        checkAndRequestPermissions();
    }

第2步:(请求许可）

private  boolean checkAndRequestPermissions() 
{
    int permissionSendMessage = ContextCompat.checkSelfPermission(this,Manifest.permission.CAMERA);
    int locationPermission = ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
    int storagePermission = ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE);
    List<String> listPermissionsNeeded = new ArrayList<>();
    if (locationPermission != PackageManager.PERMISSION_GRANTED) {
        listPermissionsNeeded.add(Manifest.permission.ACCESS_FINE_LOCATION);
    }
    if (permissionSendMessage != PackageManager.PERMISSION_GRANTED) {
        listPermissionsNeeded.add(Manifest.permission.CAMERA);
    }
    if (storagePermission != PackageManager.PERMISSION_GRANTED) {
        listPermissionsNeeded.add(Manifest.permission.WRITE_EXTERNAL_STORAGE);
    }
    if (!listPermissionsNeeded.isEmpty()) {
        ActivityCompat.requestPermissions(this, listPermissionsNeeded.toArray(new String[listPermissionsNeeded.size()]),permsRequestCode);
        return false;
    }
    return true;
}

第3步:(覆盖方法实施）

 @Override
public void onRequestPermissionsResult(int requestCode,
                                       String permissions[], int[] grantResults) {
    switch (requestCode) {
        case 200: {

            Map<String, Integer> perms = new HashMap<>();
            // Initialize the map with both permissions
            perms.put(Manifest.permission.CAMERA, PackageManager.PERMISSION_GRANTED);
            perms.put(Manifest.permission.ACCESS_FINE_LOCATION, PackageManager.PERMISSION_GRANTED);
            perms.put(Manifest.permission.WRITE_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
            // Fill with actual results from user
            if (grantResults.length > 0) {
                for (int i = 0; i < permissions.length; i++)
                    perms.put(permissions[i], grantResults[i]);
                // Check for both permissions
                if (perms.get(Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                        && perms.get(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
                    // process the normal flow
                    //else any one or both the permissions are not granted
                    waitAndNavigateToOnboardingTutorial();
                } else {
                    //permission is denied (this is the first time, when "never ask again" is not checked) so ask again explaining the usage of permission

// // shouldShowRequestPermissionRationale将返回true //显示对话框或小吃栏说明必要，然后重试，否则继续进行设置。 if（ActivityCompat.shouldShowRequestPermissionRationale（this，Manifest.permission.CAMERA）|| ActivityCompat.shouldShowRequestPermissionRationale（this，Manifest.permission.ACCESS_FINE_LOCATION） || ActivityCompat.shouldShowRequestPermissionRationale（this，Manifest.permission.WRITE_EXTERNAL_STORAGE））{ showDialogOK（＆＃34;此应用所需的相机，存储和位置服务许可＆＃34;， new DialogInterface.OnClickListener（）{ @覆盖 public void onClick（DialogInterface对话框，int which）{ 开关（哪个）{ case DialogInterface.BUTTON_POSITIVE： checkAndRequestPermissions（）; 打破; case DialogInterface.BUTTON_NEGATIVE： //通过禁用相关功能或退出应用程序来继续逻辑。打破; } } }）; } //权限被拒绝（永远不会再次询问） // shouldShowRequestPermissionRationale将返回false 其他{ Toast.makeText（this，＆＃34;转到设置并启用权限＆＃34;，Toast.LENGTH_LONG）。节目（）; // //通过禁用相关功能或退出应用程序来继续逻辑。 } } } } }

第4步：

 private void showDialogOK(String message, DialogInterface.OnClickListener okListener) {
    new AlertDialog.Builder(this)
            .setMessage(message)
            .setPositiveButton("OK", okListener)
            .setNegativeButton("Cancel", okListener)
            .create()
            .show();
}

Answer 2

可能与使用

有关

 ContextCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION);

而不是

 ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.ACCESS_FINE_LOCATION);

当我遇到类似问题时，它为我修好了。

没有你的logcat内容真的很难说。试着告诉我们究竟发生了什么。如有必要，我会编辑这个答案。

Answer 3

private boolean requestPermission() {
    int hasLocationPermission = ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION);
    if (hasLocationPermission != PackageManager.PERMISSION_GRANTED) {
        if (!ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)) {
            showMessageOKCancel(getResources().getString(R.string.phone_permission_needed),
                    new DialogInterface.OnClickListener() {
                        @Override
                        public void onClick(DialogInterface dialog, int which) {
                            switch (which) {
                                case DialogInterface.BUTTON_POSITIVE:
                                    ActivityCompat.requestPermissions(activity, new String[] {Manifest.permission.ACCESS_FINE_LOCATION},
                                            REQUEST_CODE_SOME_FEATURES_PERMISSIONS);
                                    break;
                                case DialogInterface.BUTTON_NEGATIVE:
                                    // proceed with logic by disabling the related features or quit the app.
                                    errorMessage.setText("Permissions not provided or permanently denied earlier.");
                                    providePermissions.setVisibility(View.VISIBLE);
                                    break;
                            }
                        }
                    });
            return false;
        }
        ActivityCompat.requestPermissions(this, new String[] {Manifest.permission.ACCESS_FINE_LOCATION},
                REQUEST_CODE_SOME_FEATURES_PERMISSIONS);
        return false;
    }
    return true;
}

我在代码中发现错误的一件事是，当“shouldShowRequestPermissionRationale”条件为false时，您只是要求权限。无论如何你必须要求权限。这是一个有效的代码。你可以尝试一下。

如何让我的应用程序请求许可？

3 个答案: