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
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();
}
}
}
}
其他回答
扩展上面mVck的答案，下面的逻辑确定是否“Never ask again”已经为给定的权限请求进行了检查:
bool bStorage = grantResults[0] == Permission.Granted;
bool bNeverAskForStorage =
!bStorage && (
_bStorageRationaleBefore == true && _bStorageRationaleAfter == false ||
_bStorageRationaleBefore == false && _bStorageRationaleAfter == false
);
摘自下面(完整的例子见这个答案)
private bool _bStorageRationaleBefore;
private bool _bStorageRationaleAfter;
private const int ANDROID_PERMISSION_REQUEST_CODE__SDCARD = 2;
//private const int ANDROID_PERMISSION_REQUEST_CODE__CAMERA = 1;
private const int ANDROID_PERMISSION_REQUEST_CODE__NONE = 0;
public override void OnRequestPermissionsResult(int requestCode, string[] permissions, [GeneratedEnum] Permission[] grantResults)
{
base.OnRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode)
{
case ANDROID_PERMISSION_REQUEST_CODE__SDCARD:
_bStorageRationaleAfter = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
bool bStorage = grantResults[0] == Permission.Granted;
bool bNeverAskForStorage =
!bStorage && (
_bStorageRationaleBefore == true && _bStorageRationaleAfter == false ||
_bStorageRationaleBefore == false && _bStorageRationaleAfter == false
);
break;
}
}
private List<string> GetRequiredPermissions(out int requestCode)
{
// Android v6 requires explicit permission granting from user at runtime for security reasons
requestCode = ANDROID_PERMISSION_REQUEST_CODE__NONE; // 0
List<string> requiredPermissions = new List<string>();
_bStorageRationaleBefore = ShouldShowRequestPermissionRationale(Android.Manifest.Permission.WriteExternalStorage);
Permission writeExternalStoragePerm = ApplicationContext.CheckSelfPermission(Android.Manifest.Permission.WriteExternalStorage);
//if(extStoragePerm == Permission.Denied)
if (writeExternalStoragePerm != Permission.Granted)
{
requestCode |= ANDROID_PERMISSION_REQUEST_CODE__SDCARD;
requiredPermissions.Add(Android.Manifest.Permission.WriteExternalStorage);
}
return requiredPermissions;
}
protected override void OnCreate(Bundle savedInstanceState)
{
base.OnCreate(savedInstanceState);
// Android v6 requires explicit permission granting from user at runtime for security reasons
int requestCode;
List<string> requiredPermissions = GetRequiredPermissions(out requestCode);
if (requiredPermissions != null && requiredPermissions.Count > 0)
{
if (requestCode >= ANDROID_PERMISSION_REQUEST_CODE__SDCARD)
{
_savedInstanceState = savedInstanceState;
RequestPermissions(requiredPermissions.ToArray(), requestCode);
return;
}
}
}
OnCreate2(savedInstanceState);
}
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
switch (requestCode) {
case PERMISSIONS_REQUEST_EXTERNAL_STORAGE: {
if (grantResults.length > 0) {
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
// Denied
} else {
if (ActivityCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
// To what you want
} else {
// Bob never checked click
}
}
}
}
}
}
你可以听漂亮。
侦听器
interface PermissionListener {
fun onNeedPermission()
fun onPermissionPreviouslyDenied(numberDenyPermission: Int)
fun onPermissionDisabledPermanently(numberDenyPermission: Int)
fun onPermissionGranted()
}
MainClass的权限
class PermissionUtil {
private val PREFS_FILENAME = "permission"
private val TAG = "PermissionUtil"
private fun shouldAskPermission(context: Context, permission: String): Boolean {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
val permissionResult = ActivityCompat.checkSelfPermission(context, permission)
if (permissionResult != PackageManager.PERMISSION_GRANTED) {
return true
}
}
return false
}
fun checkPermission(context: Context, permission: String, listener: PermissionListener) {
Log.i(TAG, "CheckPermission for $permission")
if (shouldAskPermission(context, permission)) {
// Load history permission
val sharedPreference = context.getSharedPreferences(PREFS_FILENAME, 0)
val numberShowPermissionDialog = sharedPreference.getInt(permission, 0)
if (numberShowPermissionDialog == 0) {
(context as? Activity)?.let {
if (ActivityCompat.shouldShowRequestPermissionRationale(it, permission)) {
Log.e(TAG, "User has denied permission but not permanently")
listener.onPermissionPreviouslyDenied(numberShowPermissionDialog)
} else {
Log.e(TAG, "Permission denied permanently.")
listener.onPermissionDisabledPermanently(numberShowPermissionDialog)
}
} ?: kotlin.run {
listener.onNeedPermission()
}
} else {
// Is FirstTime
listener.onNeedPermission()
}
// Save history permission
sharedPreference.edit().putInt(permission, numberShowPermissionDialog + 1).apply()
} else {
listener.onPermissionGranted()
}
}
}
以这种方式使用
PermissionUtil().checkPermission(this, Manifest.permission.ACCESS_FINE_LOCATION,
object : PermissionListener {
override fun onNeedPermission() {
log("---------------------->onNeedPermission")
// ActivityCompat.requestPermissions(this@SplashActivity,
// Array(1) { Manifest.permission.ACCESS_FINE_LOCATION },
// 118)
}
override fun onPermissionPreviouslyDenied(numberDenyPermission: Int) {
log("---------------------->onPermissionPreviouslyDenied")
}
override fun onPermissionDisabledPermanently(numberDenyPermission: Int) {
log("---------------------->onPermissionDisabled")
}
override fun onPermissionGranted() {
log("---------------------->onPermissionGranted")
}
})
在activity或fragmnet中覆盖onRequestPermissionsResult
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
if (requestCode == 118) {
if (permissions[0] == Manifest.permission.ACCESS_FINE_LOCATION && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
getLastLocationInMap()
}
}
}
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。
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;
}
