来自相同权限组的多个运行时权限

Created: November-22, 2018

在清单中，我们从两个组中获得了危险的运行时权限。

<!-- Required to read and write to shredPref file. -->
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>

<!-- Required to get location of device. -->
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>

在需要权限的活动中。请注意，在任何需要权限的活动中检查权限非常重要，因为在应用程序处于后台时可以撤消权限，然后应用程序将崩溃。

final private int REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS = 124;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.act_layout);
    
    // A simple check of whether runtime permissions need to be managed 
    if (Build.VERSION.SDK_INT >= 23) {
        checkMultiplePermissions();
    }

我们只需要从每个组中请求其中一个的权限，并且除非用户撤消该权限，否则授予该组的所有其他权限。

private void checkMultiplePermissions() {

    if (Build.VERSION.SDK_INT >= 23) {
        List<String> permissionsNeeded = new ArrayList<String>();
        List<String> permissionsList = new ArrayList<String>();
        
        if (!addPermission(permissionsList, android.Manifest.permission.ACCESS_FINE_LOCATION)) {
            permissionsNeeded.add("GPS");
        }

        if (!addPermission(permissionsList, android.Manifest.permission.READ_EXTERNAL_STORAGE)) {
            permissionsNeeded.add("Read Storage");
        }
        
        if (permissionsList.size() > 0) {
            requestPermissions(permissionsList.toArray(new String[permissionsList.size()]),
                    REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS);
            return;
        }
    }
}

private boolean addPermission(List<String> permissionsList, String permission) {
    if (Build.VERSION.SDK_INT >= 23)

        if (checkSelfPermission(permission) != PackageManager.PERMISSION_GRANTED) {
            permissionsList.add(permission);

            // Check for Rationale Option
            if (!shouldShowRequestPermissionRationale(permission))
                return false;
        }
    return true;
}

这涉及用户允许或不允许权限的结果。在此示例中，如果不允许权限，则应用程序将被终止。

@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
    switch (requestCode) {
        case REQUEST_CODE_ASK_MULTIPLE_PERMISSIONS: {
        
            Map<String, Integer> perms = new HashMap<String, Integer>();
            // Initial
            perms.put(android.Manifest.permission.ACCESS_FINE_LOCATION, PackageManager.PERMISSION_GRANTED);
            perms.put(android.Manifest.permission.READ_EXTERNAL_STORAGE, PackageManager.PERMISSION_GRANTED);
            
            // Fill with results
            for (int i = 0; i < permissions.length; i++)
                perms.put(permissions[i], grantResults[i]);
            if (perms.get(android.Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
                    && perms.get(android.Manifest.permission.READ_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
                // All Permissions Granted
                return;
            } else {
                // Permission Denied
                if (Build.VERSION.SDK_INT >= 23) {
                    Toast.makeText(
                            getApplicationContext(),
                            "My App cannot run without Location and Storage " +
                                    "Permissions.\nRelaunch My App or allow permissions" +
                                    " in Applications Settings",
                            Toast.LENGTH_LONG).show();
                    finish();
                }
            }
        }
        break;
        default:
            super.onRequestPermissionsResult(requestCode, permissions, grantResults);
    }
}