根据这个:http://developer.android.com/preview/features/runtime-permissions.html#coding一个应用程序可以检查运行时权限和请求权限，如果它还没有被授予。弹出如下对话框:
如果用户拒绝一个重要的权限，在我看来，应用程序应该显示一个解释为什么需要权限和什么影响拒绝。该对话框有两个选项:
重试(再次请求许可) 拒绝(应用程序将工作没有该许可)。
但是，如果用户选中“Never ask again”，则不应该显示带有解释的第二个对话框，特别是如果用户之前已经拒绝了一次。 现在的问题是:我的应用程序如何知道用户是否选中了Never ask again?IMO onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults)没有给我这个信息。
第二个问题是:谷歌是否计划在权限对话框中包含一个自定义消息，以解释为什么应用程序需要权限?这样就不会出现第二个对话框，这肯定会带来更好的用户体验。
当前回答
这里有一个很好的和简单的方法来检查当前的权限状态:
@Retention(RetentionPolicy.SOURCE)
@IntDef({GRANTED, DENIED, BLOCKED_OR_NEVER_ASKED })
public @interface PermissionStatus {}
public static final int GRANTED = 0;
public static final int DENIED = 1;
public static final int BLOCKED_OR_NEVER_ASKED = 2;
@PermissionStatus
public static int getPermissionStatus(Activity activity, String androidPermissionName) {
if(ContextCompat.checkSelfPermission(activity, androidPermissionName) != PackageManager.PERMISSION_GRANTED) {
if(!ActivityCompat.shouldShowRequestPermissionRationale(activity, androidPermissionName)){
return BLOCKED_OR_NEVER_ASKED;
}
return DENIED;
}
return GRANTED;
}
警告:在用户通过用户提示接受/拒绝权限之前，在第一个应用程序启动时返回BLOCKED_OR_NEVER_ASKED(在sdk 23+设备上)
更新:
Android支持库现在似乎也有一个非常类似的类Android .support.v4.content。PermissionChecker，包含checkSelfPermission()，返回:
public static final int PERMISSION_GRANTED = 0;
public static final int PERMISSION_DENIED = -1;
public static final int PERMISSION_DENIED_APP_OP = -2;
其他回答
你可以使用
shouldShowRequestPermissionRationale()
内部
onRequestPermissionsResult()
请看下面的例子:
当用户点击按钮时检查是否有权限:
@Override
public void onClick(View v) {
if (v.getId() == R.id.appCompatBtn_changeProfileCoverPhoto) {
if (Build.VERSION.SDK_INT < 23) { // API < 23 don't need to ask permission
navigateTo(MainActivity.class); // Navigate to activity to change photos
} else {
if (ContextCompat.checkSelfPermission(SettingsActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
// Permission is not granted yet. Ask for permission...
requestWriteExternalPermission();
} else {
// Permission is already granted, good to go :)
navigateTo(MainActivity.class);
}
}
}
}
当用户回答权限对话框时，我们将进入onRequestPermissionResult:
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == WRITE_EXTERNAL_PERMISSION_REQUEST_CODE) {
// Case 1. Permission is granted.
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if (ContextCompat.checkSelfPermission(SettingsActivity.this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
== PackageManager.PERMISSION_GRANTED) {
// Before navigating, I still check one more time the permission for good practice.
navigateTo(MainActivity.class);
}
} else { // Case 2. Permission was refused
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Case 2.1. shouldShowRequest... returns true because the
// permission was denied before. If it is the first time the app is running we will
// end up in this part of the code. Because he need to deny at least once to get
// to onRequestPermissionsResult.
Snackbar snackbar = Snackbar.make(findViewById(R.id.relLayout_container), R.string.you_must_verify_permissions_to_send_media, Snackbar.LENGTH_LONG);
snackbar.setAction("VERIFY", new View.OnClickListener() {
@Override
public void onClick(View v) {
ActivityCompat.requestPermissions(SettingsActivity.this
, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}
, WRITE_EXTERNAL_PERMISSION_REQUEST_CODE);
}
});
snackbar.show();
} else {
// Case 2.2. Permission was already denied and the user checked "Never ask again".
// Navigate user to settings if he choose to allow this time.
AlertDialog.Builder builder = new AlertDialog.Builder(this);
builder.setMessage(R.string.instructions_to_turn_on_storage_permission)
.setPositiveButton(getString(R.string.settings), new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Intent settingsIntent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", getPackageName(), null);
settingsIntent.setData(uri);
startActivityForResult(settingsIntent, 7);
}
})
.setNegativeButton(getString(R.string.not_now), null);
Dialog dialog = builder.create();
dialog.show();
}
}
}
}
请不要为这个解决办法向我扔石头。
这是可行的，但有点“俗气”。
当调用requestPermissions时，注册当前时间。
mAskedPermissionTime = System.currentTimeMillis();
然后在onRequestPermissionsResult中
如果结果不允许，请再次检查时间。
if (System.currentTimeMillis() - mAskedPermissionTime < 100)
由于用户不可能那么快地点击拒绝按钮，我们知道他选择了“永不再问”，因为回调是即时的。
使用风险自负。
这里有一个很好的和简单的方法来检查当前的权限状态:
@Retention(RetentionPolicy.SOURCE)
@IntDef({GRANTED, DENIED, BLOCKED_OR_NEVER_ASKED })
public @interface PermissionStatus {}
public static final int GRANTED = 0;
public static final int DENIED = 1;
public static final int BLOCKED_OR_NEVER_ASKED = 2;
@PermissionStatus
public static int getPermissionStatus(Activity activity, String androidPermissionName) {
if(ContextCompat.checkSelfPermission(activity, androidPermissionName) != PackageManager.PERMISSION_GRANTED) {
if(!ActivityCompat.shouldShowRequestPermissionRationale(activity, androidPermissionName)){
return BLOCKED_OR_NEVER_ASKED;
}
return DENIED;
}
return GRANTED;
}
警告:在用户通过用户提示接受/拒绝权限之前，在第一个应用程序启动时返回BLOCKED_OR_NEVER_ASKED(在sdk 23+设备上)
更新:
Android支持库现在似乎也有一个非常类似的类Android .support.v4.content。PermissionChecker，包含checkSelfPermission()，返回:
public static final int PERMISSION_GRANTED = 0;
public static final int PERMISSION_DENIED = -1;
public static final int PERMISSION_DENIED_APP_OP = -2;
我也遇到过同样的问题，但我解决了。为了简化工作，我编写了一个util类来处理运行时权限。
public class PermissionUtil {
/*
* Check if version is marshmallow and above.
* Used in deciding to ask runtime permission
* */
public static boolean shouldAskPermission() {
return (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M);
}
private static boolean shouldAskPermission(Context context, String permission){
if (shouldAskPermission()) {
int permissionResult = ActivityCompat.checkSelfPermission(context, permission);
if (permissionResult != PackageManager.PERMISSION_GRANTED) {
return true;
}
}
return false;
}
public static void checkPermission(Context context, String permission, PermissionAskListener listener){
/*
* If permission is not granted
* */
if (shouldAskPermission(context, permission)){
/*
* If permission denied previously
* */
if (((Activity)context).shouldShowRequestPermissionRationale(permission)) {
listener.onPermissionPreviouslyDenied();
} else {
/*
* Permission denied or first time requested
* */
if (PreferencesUtil.isFirstTimeAskingPermission(context, permission)) {
PreferencesUtil.firstTimeAskingPermission(context, permission, false);
listener.onPermissionAsk();
} else {
/*
* Handle the feature without permission or ask user to manually allow permission
* */
listener.onPermissionDisabled();
}
}
} else {
listener.onPermissionGranted();
}
}
/*
* Callback on various cases on checking permission
*
* 1. Below M, runtime permission not needed. In that case onPermissionGranted() would be called.
* If permission is already granted, onPermissionGranted() would be called.
*
* 2. Above M, if the permission is being asked first time onPermissionAsk() would be called.
*
* 3. Above M, if the permission is previously asked but not granted, onPermissionPreviouslyDenied()
* would be called.
*
* 4. Above M, if the permission is disabled by device policy or the user checked "Never ask again"
* check box on previous request permission, onPermissionDisabled() would be called.
* */
public interface PermissionAskListener {
/*
* Callback to ask permission
* */
void onPermissionAsk();
/*
* Callback on permission denied
* */
void onPermissionPreviouslyDenied();
/*
* Callback on permission "Never show again" checked and denied
* */
void onPermissionDisabled();
/*
* Callback on permission granted
* */
void onPermissionGranted();
}
}
PreferenceUtil方法如下。
public static void firstTimeAskingPermission(Context context, String permission, boolean isFirstTime){
SharedPreferences sharedPreference = context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE;
sharedPreference.edit().putBoolean(permission, isFirstTime).apply();
}
public static boolean isFirstTimeAskingPermission(Context context, String permission){
return context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE).getBoolean(permission, true);
}
现在，您所需要的就是使用带有适当参数的方法* checkPermission*。
举个例子，
PermissionUtil.checkPermission(context, Manifest.permission.WRITE_EXTERNAL_STORAGE,
new PermissionUtil.PermissionAskListener() {
@Override
public void onPermissionAsk() {
ActivityCompat.requestPermissions(
thisActivity,
new String[]{Manifest.permission.READ_CONTACTS},
REQUEST_EXTERNAL_STORAGE
);
}
@Override
public void onPermissionPreviouslyDenied() {
//show a dialog explaining permission and then request permission
}
@Override
public void onPermissionDisabled() {
Toast.makeText(context, "Permission Disabled.", Toast.LENGTH_SHORT).show();
}
@Override
public void onPermissionGranted() {
readContacts();
}
});
我的应用程序如何知道用户是否选中了“永不再问”?
如果用户勾选“永不再问”，你将得到onPermissionDisabled上的回调。
快乐编码:)
shouldShowRequestPermissionRationale根据之前权限请求中的用户首选项返回true或false。
如果用户只是拒绝权限(不是永远)shouldShowRequestPermissionRationale将返回true。如果永远拒绝许可，则返回false。窍门是即使用户允许了权限shouldShowRequestPermissionRationale也会返回false。
因此，我们可以结合这两个条件来得到永不再问的选择与否。
因此，如果用户不允许权限，并且shouldShowRequestPermissionRationale返回false，那么这意味着用户选择永远不会再次请求权限。
https://stackoverflow.com/a/58114769/5151336
