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
对每一种许可情况的完整解释
/**
* Case 1: User doesn't have permission
* Case 2: User has permission
*
* Case 3: User has never seen the permission Dialog
* Case 4: User has denied permission once but he din't clicked on "Never Show again" check box
* Case 5: User denied the permission and also clicked on the "Never Show again" check box.
* Case 6: User has allowed the permission
*
*/
public void handlePermission() {
if (ContextCompat.checkSelfPermission(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
// This is Case 1. Now we need to check further if permission was shown before or not
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// This is Case 4.
} else {
// This is Case 3. Request for permission here
}
} else {
// This is Case 2. You have permission now you can do anything related to it
}
}
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// This is Case 2 (Permission is now granted)
} else {
// This is Case 1 again as Permission is not granted by user
//Now further we check if used denied permanently or not
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// case 4 User has denied permission but not permanently
} else {
// case 5. Permission denied permanently.
// You can open Permission setting's page from here now.
}
}
}
其他回答
开发者预览2对应用程序请求权限的方式进行了一些更改(参见http://developer.android.com/preview/support.html#preview2-notes)。
第一个对话框现在看起来像这样:
没有“永不再次显示”复选框(不像开发人员预览1)。如果用户拒绝权限，如果权限是必不可少的应用程序，它可以显示另一个对话框来解释应用程序请求该权限的原因，例如:
如果用户再次拒绝，应用程序应该关闭(如果它绝对需要该权限)或继续运行有限的功能。如果用户重新考虑(并选择重试)，则再次请求权限。这次的提示符是这样的:
第二次显示“永不再问”复选框。如果用户再次拒绝并且勾选复选框，就不会再发生任何事情。 是否勾选复选框可以通过使用Activity.shouldShowRequestPermissionRationale(String)来确定，例如:
if (shouldShowRequestPermissionRationale(Manifest.permission.WRITE_CONTACTS)) {...
这就是Android文档所说的(https://developer.android.com/training/permissions/requesting.html):
To help find the situations where you need to provide extra explanation, the system provides the Activity.shouldShowRequestPermissionRationale(String) method. This method returns true if the app has requested this permission previously and the user denied the request. That indicates that you should probably explain to the user why you need the permission. If the user turned down the permission request in the past and chose the Don't ask again option in the permission request system dialog, this method returns false. The method also returns false if the device policy prohibits the app from having that permission.
要知道用户是否拒绝了“never ask again”，你可以再次检查你的onRequestPermissionsResult中的shouldShowRequestPermissionRationale方法，当用户没有授予权限时。
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
if (requestCode == REQUEST_PERMISSION) {
// for each permission check if the user granted/denied them
// you may want to group the rationale in a single dialog,
// this is just an example
for (int i = 0, len = permissions.length; i < len; i++) {
String permission = permissions[i];
if (grantResults[i] == PackageManager.PERMISSION_DENIED) {
// user rejected the permission
boolean showRationale = shouldShowRequestPermissionRationale( permission );
if (! showRationale) {
// user also CHECKED "never ask again"
// you can either enable some fall back,
// disable features of your app
// or open another dialog explaining
// again the permission and directing to
// the app setting
} else if (Manifest.permission.WRITE_CONTACTS.equals(permission)) {
showRationale(permission, R.string.permission_denied_contacts);
// user did NOT check "never ask again"
// this is a good place to explain the user
// why you need the permission and ask if he wants
// to accept it (the rationale)
} else if ( /* possibly check more permissions...*/ ) {
}
}
}
}
}
你可以用下面的代码打开你的应用程序设置:
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", getPackageName(), null);
intent.setData(uri);
startActivityForResult(intent, REQUEST_PERMISSION_SETTING);
无法将用户直接发送到授权页面。
一旦用户标记了“不要再问”，该问题就不能再次显示。 但是可以向用户解释，他之前拒绝了权限，必须在设置中授予权限。并参考他的设置，使用以下代码:
@Override
public void onRequestPermissionsResult(int permsRequestCode, String[] permissions, int[] grantResults) {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// now, you have permission go ahead
// TODO: something
} else {
if (ActivityCompat.shouldShowRequestPermissionRationale(MainActivity.this,
Manifest.permission.READ_CALL_LOG)) {
// now, user has denied permission (but not permanently!)
} else {
// now, user has denied permission permanently!
Snackbar snackbar = Snackbar.make(findViewById(android.R.id.content), "You have previously declined this permission.\n" +
"You must approve this permission in \"Permissions\" in the app settings on your device.", Snackbar.LENGTH_LONG).setAction("Settings", new View.OnClickListener() {
@Override
public void onClick(View view) {
startActivity(new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.parse("package:" + BuildConfig.APPLICATION_ID)));
}
});
View snackbarView = snackbar.getView();
TextView textView = (TextView) snackbarView.findViewById(android.support.design.R.id.snackbar_text);
textView.setMaxLines(5); //Or as much as you need
snackbar.show();
}
}
return;
}
你可以在onRequestPermissionsResult()中检查shouldShowRequestPermissionRationale()。
https://youtu.be/C8lUdPVSzDk?t=2m23s
在onRequestPermissionsResult()中检查权限是否被授予。如果不是，检查shouldShowRequestPermissionRationale()。
如果此方法返回true，则说明为什么需要此特定权限。然后根据用户的选择再次请求permissions()。 如果它返回false，则显示一个错误消息，权限未授予，应用程序不能继续前进或特定功能被禁用。
下面是示例代码。
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case STORAGE_PERMISSION_REQUEST:
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission was granted :)
downloadFile();
} else {
// permission was not granted
if (getActivity() == null) {
return;
}
if (ActivityCompat.shouldShowRequestPermissionRationale(getActivity(), Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
showStoragePermissionRationale();
} else {
Snackbar snackbar = Snackbar.make(getView(), getResources().getString(R.string.message_no_storage_permission_snackbar), Snackbar.LENGTH_LONG);
snackbar.setAction(getResources().getString(R.string.settings), new View.OnClickListener() {
@Override
public void onClick(View v) {
if (getActivity() == null) {
return;
}
Intent intent = new Intent();
intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", getActivity().getPackageName(), null);
intent.setData(uri);
OrderDetailFragment.this.startActivity(intent);
}
});
snackbar.show();
}
}
break;
}
}
显然，谷歌maps对位置许可正是这样做的。
您可以使用if (ActivityCompat。shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)方法来检测never ask是否被检查。
更多参考:检查这个
检查是否使用了多个权限:
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.CAMERA)
|| ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)
|| ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)
|| ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.RECORD_AUDIO)) {
showDialogOK("Service Permissions are required for this app",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
switch (which) {
case DialogInterface.BUTTON_POSITIVE:
checkAndRequestPermissions();
break;
case DialogInterface.BUTTON_NEGATIVE:
// proceed with logic by disabling the related features or quit the app.
finish();
break;
}
}
});
}
//permission is denied (and never ask again is checked)
//shouldShowRequestPermissionRationale will return false
else {
explain("You need to give some mandatory permissions to continue. Do you want to go to app settings?");
// //proceed with logic by disabling the related features or quit the app.
}
解释()方法
private void explain(String msg){
final android.support.v7.app.AlertDialog.Builder dialog = new android.support.v7.app.AlertDialog.Builder(this);
dialog.setMessage(msg)
.setPositiveButton("Yes", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface paramDialogInterface, int paramInt) {
// permissionsclass.requestPermission(type,code);
startActivity(new Intent(android.provider.Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.parse("package:com.exampledemo.parsaniahardik.marshmallowpermission")));
}
})
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface paramDialogInterface, int paramInt) {
finish();
}
});
dialog.show();
}
上面的代码还将显示对话框，这将重定向到用户的应用程序设置屏幕，在那里他可以给予权限，如果选中了“永不再问”按钮。
如果你想检测所有的“状态”(第一次被拒绝，刚刚被拒绝，刚刚被“Never Ask Again”拒绝或永久拒绝)，你可以做以下事情:
创建2个布尔值:
private boolean beforeClickPermissionRat;
private boolean afterClickPermissionRat;
在请求允许之前设置第一个:
beforeClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);
在你的onRequestPermissionsResult方法中设置第二个:
afterClickPermissionRat = shouldShowRequestPermissionRationale(Manifest.permission.READ_EXTERNAL_STORAGE);
使用下面的“真值表”在onRequestPermissionsResult()中做任何你需要的事情(在检查你仍然没有权限之后):
// before after
// FALSE FALSE = Was denied permanently, still denied permanently --> App Settings
// FALSE TRUE = First time deny, not denied permanently yet --> Nothing
// TRUE FALSE = Just been permanently denied --> Changing my caption to "Go to app settings to edit permissions"
// TRUE TRUE = Wasn't denied permanently, still not denied permanently --> Nothing
