为什么再次打开应用程序时权限对话框会消失?

Why permission dialog disappear when application is open again?

我在我的项目中添加了 READ_PHONE_STATE 权限。

场景: 我刚刚打开我的应用程序,我收到权限警报 “允许我的应用程序进行和管理 phone 调用?” 现在我在后台移动我的应用程序并通过点击我的应用程序图标再次打开 结果:“允许我的应用程序进行和管理 phone 调用?” 权限弹出窗口消失。

谁能说出为什么会出现这种行为? 注意:我正在使用 launchMode="singleInstance" 并且在使用 launchMode="standard" 时一切正常。

分享我的代码:

<?xml version="1.0" encoding="utf-8"?>

<application
    android:allowBackup="true"
    android:icon="@mipmap/ic_launcher"
    android:label="@string/app_name"
    android:roundIcon="@mipmap/ic_launcher_round"
    android:supportsRtl="true"
    android:theme="@style/AppTheme">
    <activity android:name=".MainActivity" android:launchMode="singleTask">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />

            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
</application>

public class MainActivity extends AppCompatActivity {

public static final Integer REQUEST_CODE_FOR_PERMISSION = 0x1;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    askForPermission(this, Manifest.permission.READ_PHONE_STATE, REQUEST_CODE_FOR_PERMISSION);
}

public static void askForPermission(Activity context, String permission, Integer requestCode) {
    if ((Build.VERSION.SDK_INT >= 23) && (context != null) && (TextUtils.isEmpty(permission) == false)) {
        ActivityCompat.requestPermissions(context, new String[]{permission}, requestCode);
    }
}}

试试这个,

public class MainActivity extends AppCompatActivity {

    public static final Integer REQUEST_CODE_FOR_PERMISSION = 0x1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

    }

    @override
    private void onResume(){
    askForPermission(this, Manifest.permission.READ_PHONE_STATE, REQUEST_CODE_FOR_PERMISSION);
    }

    public static void askForPermission(Activity context, String permission, Integer requestCode) {
        if ((Build.VERSION.SDK_INT >= 23) && (context != null) && (TextUtils.isEmpty(permission) == false)) {
            ActivityCompat.requestPermissions(context, new String[]{permission}, requestCode);
        }
    }}

onBackPressed()

中调用 finish()
@Override
    public void onBackPressed() {
        super.onBackPressed();
        finish();
    }

这将再次启动 activity,您的代码将在 onCreate()

中运行

像这样使用运行时权限:

 public class MainActivity extends Activity {
        private static final int PERMISSION_REQUEST_CODE = 200;
        Context context;
        Activity activity;

        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            context = this;
            activity = this;
            setContentView(R.layout.activity_splash);
            if (!checkPermission()) {
                OpenActivity();
            } else {
                if (checkPermission()) {
                    requestPermissionAndContinue();
                } else {
                    OpenActivity();
                }
            }
        }

        private boolean checkPermission() {
            return ContextCompat.checkSelfPermission(this, READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED;
        }

        private void requestPermissionAndContinue() {
            if (ContextCompat.checkSelfPermission(this, READ_PHONE_STATE) != PackageManager.PERMISSION_GRANTED) {

                if (ActivityCompat.shouldShowRequestPermissionRationale(this, READ_PHONE_STATE)) {
                    AlertDialog.Builder alertBuilder = new AlertDialog.Builder(this);
                    alertBuilder.setCancelable(true);
                    alertBuilder.setTitle("Permission necessary");
                    alertBuilder.setMessage("STORAGE permission is necessary to write event!!!");
                    alertBuilder.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {
                        @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
                        public void onClick(DialogInterface dialog, int which) {
                            ActivityCompat.requestPermissions(SplashActivityANother.this, new String[]{READ_PHONE_STATE,
                            }, PERMISSION_REQUEST_CODE);
                        }
                    });
                    AlertDialog alert = alertBuilder.create();
                    alert.show();
                    Log.e("", "permission denied, show dialog");
                } else {
                    ActivityCompat.requestPermissions(this, new String[]{READ_PHONE_STATE
                    }, PERMISSION_REQUEST_CODE);

                }
            } else {
                OpenActivity();

            }
        }

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

            if (requestCode == PERMISSION_REQUEST_CODE) {
                if (permissions.length > 0 && grantResults.length > 0) {

                    boolean flag = true;
                    for (int i = 0; i < grantResults.length; i++) {
                        if (grantResults[i] != PackageManager.PERMISSION_GRANTED) {
                            flag = false;
                        }
                    }
                    if (flag) {
                        OpenActivity();
                    } else {
                        finish();
                    }

                } else {
                    finish();
                }
            } else {
                super.onRequestPermissionsResult(requestCode, permissions, grantResults);
            }
        }

        private void OpenActivity() {
            Intent i = new Intent(MainActivity.this, SecondActivity.class);
            startActivity(i);
        }
    }

并添加 <uses-permission android:name="android.permission.READ_PHONE_STATE" /> 进入清单文件。

希望对您有所帮助

基于单任务行为

如果 activity 的实例已存在于单独的任务中,系统将通过调用其 onNewIntent() 方法将意图路由到现有实例,而不是创建一个新实例。

https://developer.android.com/guide/components/activities/tasks-and-back-stack#TaskLaunchModes

我能够通过处理

中的代码来解决这个问题

onNewIntent(意图意图)

@Override
protected void onNewIntent(Intent intent) {
    super.onNewIntent(intent);
    askForPermission(this, Manifest.permission.READ_PHONE_STATE, REQUEST_CODE_FOR_PERMISSION);
}