我有同样的问题,我想通了。为了让生活更简单,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();
}
}
而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,您只需使用带有适当参数的方法 checkPermission。
这是一个例子,
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();
}
});
案例1:应用没有权限,用户也没有
之前请求过许可。在这种情况下,
shouldShowRequestPermissionRationale() 将返回 false,因为这
是我们第一次询问用户。
案例 2:用户拒绝了权限并选择了“不要询问”
再次”,在这种情况下, shouldShowRequestPermissionRationale() 也会
返回 false。
我想在案例 2 中将用户发送到应用程序的设置页面。
如何区分这两种情况?
对于案例 1,您将在 onPermissionAsk 上获得回调,对于案例 2,您将在 onPermissionDisabled 上获得回调。
编码愉快:)