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
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”?
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。
正确使用shouldShowRequestPermissionRationale是on onRequestPermissionsResult。
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.appcompat.widget.LinearLayoutCompat
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
tools:context=".MainActivity"
android:gravity="center">
<androidx.appcompat.widget.AppCompatButton
android:id="@+id/btn_camera"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Camera"
android:textAllCaps="false"
android:background="@color/purple_200"
android:layout_marginTop="20dp"
>
</androidx.appcompat.widget.AppCompatButton>
<androidx.appcompat.widget.AppCompatButton
android:id="@+id/btn_storage"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Storage"
android:textAllCaps="false"
android:background="@color/purple_200"
android:layout_marginTop="30dp"
>
</androidx.appcompat.widget.AppCompatButton>
</androidx.appcompat.widget.LinearLayoutCompat>
enter code here
MainActivity.kt
package com.example.myapplication
import android.Manifest
import android.content.pm.PackageManager
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Button
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
class MainActivity : AppCompatActivity() {
private val TAG = "MainActivity"
lateinit var btnCamera: Button
private val cameraRequestCode = 100
lateinit var btnStorage: Button
private val storageRequestCode = 200
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
btnCamera = findViewById(R.id.btn_camera)
btnStorage = findViewById(R.id.btn_storage)
btnCamera.setOnClickListener {
checkPermission(android.Manifest.permission.CAMERA, cameraRequestCode)
}
btnStorage.setOnClickListener {
checkPermission(android.Manifest.permission.READ_EXTERNAL_STORAGE, storageRequestCode)
}
}
private fun checkPermission(permissionName: String, requestCode: Int) {
/**
* if the permission is given means it will give the permissionNumber = 0
* if the permission is not given means it will give the permissionNumber =-1
* It s same as we are checking for PackageManager.PERMISSION_DENIED =-1 & PackageManager.GRANTED=0
*/
val permissionNumber: Int =
ContextCompat.checkSelfPermission(this@MainActivity, permissionName)
if (permissionNumber == PackageManager.PERMISSION_GRANTED) {
} else if (permissionNumber == PackageManager.PERMISSION_DENIED) {
askpermission(permissionName, requestCode, permissionNumber)
}
}
private fun askpermission(permissionName: String, permissionCode: Int, permissionNumner: Int) {
ActivityCompat.requestPermissions(
this@MainActivity,
arrayOf(permissionName),
permissionCode
)
}
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == cameraRequestCode) {
if (permissions.size > 0) {
if (permissions[0].toString().equals(Manifest.permission.CAMERA, ignoreCase = true)) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(applicationContext,"Permission Granted",Toast.LENGTH_SHORT).show()
}else{
if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
var permissionDeniedStatus= checkDeniedPermissionStatus(permissions[0]);
if(permissionDeniedStatus){
/**
* Permission Denied
*/
Toast.makeText(applicationContext,"Permission Denied",Toast.LENGTH_SHORT).show()
}else{
/**
* Permission Denied and Selected Don t ask again.
*/
showDialog("Permission Denied","Permission Denied Permanently\nOpen Setting to allow")
}
}
}
}
}
}else if (requestCode == storageRequestCode) {
if(permissions[0].toString().equals(Manifest.permission.READ_EXTERNAL_STORAGE, ignoreCase = true)){
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(applicationContext,"Permission Granted",Toast.LENGTH_SHORT).show()
}
}else{
if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
var permissionDeniedStatus= checkDeniedPermissionStatus(permissions[0]);
if(permissionDeniedStatus){
/**
* Permission Denied
*/
Toast.makeText(applicationContext,"Permission Denied",Toast.LENGTH_SHORT).show()
}else{
/**
* Permission Denied and Selected Don t ask again.
*/
showDialog("Permission Denied","Permission Denied Permanently\nOpen Setting to allow")
}
}
}
}
}
}
private fun checkDeniedPermissionStatus(permissionName: String) :Boolean{
val permissionDeniedStatus: Boolean = ActivityCompat.shouldShowRequestPermissionRationale(this@MainActivity, permissionName)
return permissionDeniedStatus
}
private fun showDialog(title: String, message: String) {
val builder = AlertDialog.Builder(this)
builder.setTitle(title)
builder.setMessage(message)
builder.setPositiveButton(android.R.string.yes) { dialog, which ->
}
builder.setNegativeButton(android.R.string.no) { dialog, which ->
}
builder.show()
}
}
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”?
这段代码要求用户在运行时请求权限， 如果用户允许，执行结果方法， 如果用户拒绝，它会用描述和用户拒绝再次询问(它会用说明再次询问)， 但如果用户选择永远不会再问。 它处理永不再问，显示打开设置选项与说明。
public String storagePermissions = Manifest.permission.READ_EXTERNAL_STORAGE;
private static final int REQUEST_ACCESS =101;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if(checkSelfPermission(storagePermissions)== PackageManager.PERMISSION_GRANTED){
result(); // result is your block of code
}else {
requestPermissions(new String[]{storagePermissions},REQUEST_ACCESS);
}
}
else{
result(); //so if user is lower than api verison M, no permission is requested
}
}
private void showMessageOKCancel(String message, DialogInterface.OnClickListener okListener) {
new AlertDialog.Builder(MainActivity.this)
.setMessage(message)
.setTitle("Hi User..")
.setPositiveButton("Ok", okListener)
.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) { //idea calling showMessage funtion again
Snackbar mySnackbar = Snackbar.make( findViewById(R.id.coordinatorlayout),"You Press Cancel.. ", Snackbar.LENGTH_INDEFINITE);
mySnackbar.setAction("Exit", new cancelButton());
mySnackbar.show();
}
})
.create()
.show();
}
private void result(){
//your code
}
@RequiresApi(api = Build.VERSION_CODES.M)
public class NeverAskAgain implements View.OnClickListener{
@Override
public void onClick(View view)
{
goToSettings();
}
}
@RequiresApi(api = Build.VERSION_CODES.M)
private void goToSettings() {
Intent myAppSettings = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS, Uri.parse("package:" + getPackageName()));
finish();
myAppSettings.addCategory(Intent.CATEGORY_DEFAULT);
myAppSettings.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
startActivityForResult(myAppSettings, REQUEST_APP_SETTINGS);
}
public class cancelButton implements View.OnClickListener{
@Override
public void onClick(View view){
Toast.makeText(MainActivity.this,"To use this app , you must grant storage permission",Toast.LENGTH_SHORT);
finish();
}
}
@Override
@RequiresApi(api = Build.VERSION_CODES.M)
public void onRequestPermissionsResult(int requestCode, @NonNull String permissions[], @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode,permissions,grantResults);
switch(requestCode) {
case REQUEST_ACCESS:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// permission is granted
result();
break;
}
else if (!shouldShowRequestPermissionRationale(permissions[0])){
showMessageOKCancel("You choose Never Ask Again,option",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
Snackbar mySnackbar = Snackbar.make(findViewById(R.id.coordinatorlayout), "Permission=>Storage=>On", Snackbar.LENGTH_INDEFINITE);
mySnackbar.setAction("Settings", new NeverAskAgain());
mySnackbar.show();
}
});
break;
}
else {
showMessageOKCancel("You Denid permission Request..",
new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
requestPermissions(new String[]{storagePermissions}, REQUEST_ACCESS);
}
});
break;
}
}
}
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。
