我正在翻阅关于Android m中的新权限模型的官方文档。它讨论了shouldShowRequestPermissionRationale()函数，如果应用程序之前请求了此权限，并且用户拒绝了请求，该函数将返回true。如果用户在过去拒绝了权限请求并选择Don't ask again选项，则此方法返回false。
但是我们如何区分以下两种情况呢?
案例1:应用程序没有权限，之前也没有向用户请求过权限。在这种情况下，shouldShowRequestPermissionRationale()将返回false，因为这是我们第一次请求用户。
情况2:用户拒绝了权限并选择了“不要再问了”，在这种情况下shouldShowRequestPermissionRationale()将返回false。
我想把用户发送到案例2中的应用设置页面。我怎么微分这两种情况呢?
当前回答
如果有人喜欢，就发布另一种选择。你可以使用EasyPermissions，这是由谷歌本身提供的，如前所述，“简化Android M系统权限”。
然后你不必直接处理shouldShowRequestPermissionRationale。
其他回答
可能对某人有用:——
我注意到的是，如果我们在onRequestPermissionsResult()回调方法中检查shouldshowrequestpermissionration理()标志，它只显示两种状态。
状态1:-返回true:——任何时候用户单击Deny permissions(包括第一次)。
状态2:-返回false:-如果用户选择“永不再问”。
链接到详细的工作示例。
更新
我相信下面CanC的答案是正确的，应该遵循。唯一确定的方法是在onRequestPermissionResult回调中使用shouldShowPermissionRationale来验证这一点。
==
我最初的回答是:
我发现的唯一方法是自己跟踪这是否是第一次(例如使用共享的偏好)。如果不是第一次，则使用shouldShowRequestPermissionRationale()进行区分。
另见:Android M -检查运行时权限-如何确定用户是否勾选了“永不再问”?
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checkPermission方法和适当的参数。
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();
}
});
Case 1: The app doesn't have a permission and the user has not been asked for the permission before. In this case, shouldShowRequestPermissionRationale() will return false because this is the first time we're asking the user. Case 2: The user has denied the permission and selected "Don't ask again", in this case too shouldShowRequestPermissionRationale() will return false. I would want to send the user to the App's settings page in Case 2. How do i go about differentiating these two cases?
你会得到回调onPermissionAsk的情况1，和onPermissionDisabled的情况2。
快乐编码:)
如果有人对Kotlin解决方案感兴趣，我将@muthuraj的答案重构为Kotlin。它也现代化了一点，有一个完成块，而不是监听器。
PermissionUtil
object PermissionUtil {
private val PREFS_FILE_NAME = "preference"
fun firstTimeAskingPermission(context: Context, permission: String, isFirstTime: Boolean) {
val sharedPreference = context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE)
sharedPreference.preferences.edit().putBoolean(permission,
isFirstTime).apply()
}
fun isFirstTimeAskingPermission(context: Context, permission: String): Boolean {
val sharedPreference = context.getSharedPreferences(PREFS_FILE_NAME, MODE_PRIVATE)
return sharedPreference.preferences.getBoolean(permission,
true)
}
}
PermissionHandler
enum class CheckPermissionResult {
PermissionAsk,
PermissionPreviouslyDenied,
PermissionDisabled,
PermissionGranted
}
typealias PermissionCheckCompletion = (CheckPermissionResult) -> Unit
object PermissionHandler {
private fun shouldAskPermission(context: Context, permission: String): Boolean {
return ContextCompat.checkSelfPermission(context,
permission) != PackageManager.PERMISSION_GRANTED
}
fun checkPermission(context: Context, permission: String, completion: PermissionCheckCompletion) {
// If permission is not granted
if (shouldAskPermission(context, permission)) {
//If permission denied previously
if ((context as Activity).shouldShowRequestPermissionRationale(permission)) {
completion(CheckPermissionResult.PermissionPreviouslyDenied)
} else {
// Permission denied or first time requested
if (PermissionUtil.isFirstTimeAskingPermission(context,
permission)) {
PermissionUtil.firstTimeAskingPermission(context,
permission,
false)
completion(CheckPermissionResult.PermissionAsk)
} else {
// Handle the feature without permission or ask user to manually allow permission
completion(CheckPermissionResult.PermissionDisabled)
}
}
} else {
completion(CheckPermissionResult.PermissionGranted)
}
}
}
实现
PermissionHandler.checkPermission(activity,
Manifest.permission.CAMERA) { result ->
when (result) {
CheckPermissionResult.PermissionGranted -> {
// openCamera()
}
CheckPermissionResult.PermissionDisabled -> {
// displayAlert(noPermissionAlert)
}
CheckPermissionResult.PermissionAsk -> {
// requestCameraPermissions()
}
CheckPermissionResult.PermissionPreviouslyDenied -> {
// displayAlert(permissionRequestAlert)
}
}
}
如果有人喜欢，就发布另一种选择。你可以使用EasyPermissions，这是由谷歌本身提供的，如前所述，“简化Android M系统权限”。
然后你不必直接处理shouldShowRequestPermissionRationale。
