等待用户许可

Wait for user permission

我构建了一个在启动时对 GPS 进行采样的应用程序。 您可能知道,在 运行 时间内从 Android M 及以上请求权限。

因此,就我而言,我首先检查是否需要权限,如下所示:

private void permissionForAndroidM()
{
    if (Build.VERSION.SDK_INT > 22) {
        String[] allPermissionNeeded = {
                Manifest.permission.WRITE_EXTERNAL_STORAGE,
                Manifest.permission.ACCESS_FINE_LOCATION,
                Manifest.permission.ACCESS_COARSE_LOCATION,
                Manifest.permission.CAMERA,
                Manifest.permission.RECORD_AUDIO};

        List<String> permissionNeeded = new ArrayList<>();
        for (String permission : allPermissionNeeded)
            if (checkSelfPermission(permission) != PackageManager.PERMISSION_GRANTED)
                permissionNeeded.add(permission);
        if (permissionNeeded.size() > 0) {
            requestPermissions(permissionNeeded.toArray(new String[0]), 0);
        }
    }
}

Android 继续运行编码并请求 GPS 数据(= 崩溃,因为用户未接受权限请求) .

我找到了很多关于等待用户输入的解决方案(比如使用 DialogInterface.OnClickListenerlink,但在这种情况下无法实现,因为我没有创建对话框)。

底线,问题:我如何等待用户从 Android 权限对话框中回答?

您可以处理用户响应覆盖方法

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

来自你的activity。

Android continuing running the code and asking for GPS data ( = crash, because the user didn't accept the permission request).

与 Android 中的许多事情一样,requestPermissions() 是异步的。到此方法 returns.

时,用户甚至还没有收到权限提示

How can I wait for user answer from the Android permission dialog ?

你不知道。

如果您发现自己已经获得许可,那么您就可以开始工作了。如果您发现必须请求许可,您可以延迟完成这项工作,直到获得许可,在 onRequestPermissionsResult().

我按以下方式工作:

1- 创建了一个 Boolean 助手来检查授予的权限:

public class UtilPermissions {
    public static boolean hasPermissions(Context context, String... allPermissionNeeded)
    {
        if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M
                && context != null && allPermissionNeeded != null) 
            for (String permission : allPermissionNeeded) 
                if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED)
                     return false;
        return true;
    }
}

2- 创建了一个 Splash 屏幕:

public class Splash extends Activity {
    private static final int PERMISSION_ALL = 0;
    private Handler h;
    private Runnable r;
  /*  
    SharedPreferences mPrefs;
    final String settingScreenShownPref = "settingScreenShown";
    final String versionCheckedPref = "versionChecked";
  */
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        h = new Handler();
        r = new Runnable() {
            @Override
            public void run() {
                Toast.makeText(Splash.this, "Runnable started", Toast.LENGTH_SHORT).show();

  /*          // (OPTIONAL) these lines to check if the `First run` ativity is required
                int versionCode = BuildConfig.VERSION_CODE;
                String versionName = BuildConfig.VERSION_NAME;

                mPrefs = PreferenceManager.getDefaultSharedPreferences(getApplicationContext());
                SharedPreferences.Editor editor = mPrefs.edit();

                Boolean settingScreenShown = mPrefs.getBoolean(settingScreenShownPref, false);
                int savedVersionCode = mPrefs.getInt(versionCheckedPref, 1);

                if (!settingScreenShown || savedVersionCode != versionCode) {
                    startActivity(new Intent(Splash.this, FirstRun.class));
                    editor.putBoolean(settingScreenShownPref, true);
                    editor.putInt(versionCheckedPref, versionCode);
                    editor.commit();
                }
                else
  */
                startActivity(new Intent(Splash.this, MainActivity.class));
                finish();    
            }
        };

        String[] PERMISSIONS = {
                READ_PHONE_STATE,
                MODIFY_AUDIO_SETTINGS,
                ACCESS_FINE_LOCATION,
                READ_SMS
        };

        if(!UtilPermissions.hasPermissions(this, PERMISSIONS)){
            ActivityCompat.requestPermissions(this, PERMISSIONS, PERMISSION_ALL);
        }
        else
            h.postDelayed(r, 1500);
    }

  // Put the below OnRequestPermissionsResult code here
}

3- 创建了 OnRequestPermissionsResult 如下:

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

    int index = 0;
    Map<String, Integer> PermissionsMap = new HashMap<String, Integer>();
    for (String permission : permissions){
        PermissionsMap.put(permission, grantResults[index]);
        index++;
    }

    if((PermissionsMap.get(ACCESS_FINE_LOCATION) != 0)
            || PermissionsMap.get(READ_SMS) != 0){
        Toast.makeText(this, "Location and SMS permissions are a must", Toast.LENGTH_SHORT).show();
        finish();
    }
    else
    {
        h.postDelayed(r, 1500);
    }
}

4- 在 AndroidManifest.xml 中将 Splash 屏幕定义为 Launcher 为:

<activity
    android:name=".MainActivity"
    android:label="@string/app_name"
    android:theme="@style/AppTheme.NoActionBar">
</activity>

<activity
    android:name=".Splash"
    android:configChanges="orientation|keyboardHidden|screenSize"
    android:theme="@style/SplashTheme">

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

5- 在 styles.xml 中将 SplashTheme 定义为:

<style name="SplashTheme" parent="Theme.AppCompat.NoActionBar">
    <item name="android:windowBackground">@drawable/Splash</item>
</style>

6- @drawable/Splash.xmls 是:

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:drawable="@color/lightgray"/>

    <item>
        <bitmap
            android:gravity="center"
            android:src="@mipmap/ic_launcher"/>
    </item>

</layer-list>

7- 在 values/colors.xmls 中,lightgray 颜色定义如下:

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="lightgray">#D3D3D3</color>
</resources>

请求一个权限后,while循环,你可以检查权限是否连续授予,如果授予你可以更改值并退出while循环。

Boolean isAnswered = true;

    while(isAnswered){

        if (ActivityCompat.checkSelfPermission(getApplication(), Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(getApplication(), Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED) {
            Log.d("isanswered", String.valueOf(isAnswered));
        }
        else{
            isAnswered = false;
            Log.d("isanswered", String.valueOf(isAnswered));
        }
    }

我认为这已经晚了,但也许它会对某人有所帮助。 因此,假设您想在您的应用程序中启动一个位置侦听器,但您还没有注册侦听器的权限,但您希望在您的权限被授予后立即收到通知。只听那个事件。

object PermissionsHelper{
     private val listeners = ArrayList<PermissionListener>()

     fun addListener(listener: PermissionListener){ ... }

     fun notifyPermissionsGranted(list : ArrayList<String>) { ... }
     /** OR */
     fun notifyPermissionsStatusChanged() { ... } // and all of them will check again.
}

所以在你想听位置的地方你会检查你的许可是否被授予,如果没有你打电话给PermissionsHelper.getInstance().addListener(...) 在 UI 中,当 onRequestPermissionsResult 获得授予的权限时,您将调用 ass following PermissionsHelper.getInstance().notifyPermissionsGranted( ... ) 然后您继续向系统注册位置。