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老司机带你一文读懂Android运行时权限

 
老司机发车了,未到终点请勿下车. 嘟嘟嘟~~~
 运行时权限从Android 6.0版本开始的,如果你的项目中 targetSdkVersion/compileSdkVersion 大于等于23,那么你就必须要考虑动态权限了。

权限又分为普通权限和危险权限。
普通权限如下:
android.permission.ACCESS LOCATIONEXTRA_COMMANDS 
android.permission.ACCESS NETWORKSTATE
android.permission.ACCESS NOTIFICATIONPOLICY
android.permission.ACCESS WIFISTATE
android.permission.ACCESS WIMAXSTATE
android.permission.BLUETOOTH
android.permission.BLUETOOTH_ADMIN
android.permission.BROADCAST_STICKY
android.permission.CHANGE NETWORKSTATE
android.permission.CHANGE WIFIMULTICAST_STATE
android.permission.CHANGE WIFISTATE
android.permission.CHANGE WIMAXSTATE
android.permission.DISABLE_KEYGUARD
android.permission.EXPAND STATUSBAR
android.permission.FLASHLIGHT
android.permission.GET_ACCOUNTS
android.permission.GET PACKAGESIZE
android.permission.INTERNET
android.permission.KILL BACKGROUNDPROCESSES
android.permission.MODIFY AUDIOSETTINGS
android.permission.NFC
android.permission.READ SYNCSETTINGS
android.permission.READ SYNCSTATS
android.permission.RECEIVE BOOTCOMPLETED
android.permission.REORDER_TASKS
android.permission.REQUEST INSTALLPACKAGES
android.permission.SET TIMEZONE
android.permission.SET_WALLPAPER
android.permission.SET WALLPAPERHINTS
android.permission.SUBSCRIBED FEEDSREAD
android.permission.TRANSMIT_IR
android.permission.USE_FINGERPRINT
android.permission.VIBRATE
android.permission.WAKE_LOCK
android.permission.WRITE SYNCSETTINGS
com.android.alarm.permission.SET_ALARM
com.android.launcher.permission.INSTALL_SHORTCUT
com.android.launcher.permission.UNINSTALL_SHORTCUT

普通权限是当需要用到时,只需要在清单文件中声明就可。危险权限除了需要在清单文件中声明外,还需在代码中动态进行判断申请。

危险权限如下:
android.permission-group.CALENDAR   
android.permission.READ_CALENDAR
android.permission.WRITE_CALENDAR

android.permission-group.CAMERA
android.permission.CAMERA

android.permission-group.CONTACTS
android.permission.READ_CONTACTS
android.permission.WRITE_CONTACTS
android.permission.GET_ACCOUNTS

android.permission-group.LOCATION
android.permission.ACCESS_FINE_LOCATION
android.permission.ACCESS_COARSE_LOCATION

android.permission-group.MICROPHONE
android.permission.RECORD_AUDIO

android.permission-group.PHONE
android.permission.READ_PHONE_STATE
android.permission.CALL_PHONE
android.permission.READ_CALL_LOG
android.permission.WRITE_CALL_LOG
com.android.voicemail.permission.ADD_VOICEMAIL
android.permission.USE_SIP
android.permission.PROCESS_OUTGOING_CALLS

android.permission-group.SENSORS
android.permission.BODY_SENSORS

android.permission-group.SMS
android.permission.SEND_SMS
android.permission.RECEIVE_SMS
android.permission.READ_SMS
android.permission.RECEIVE_WAP_PUSH
android.permission.RECEIVE_MMS
android.permission.READ_CELL_BROADCASTS

android.permission-group.STORAGE
android.permission.READ_EXTERNAL_STORAGE
android.permission.WRITE_EXTERNAL_STORAGE

危险权限是按组划分的,每一组中当某一个权限被允许或者拒绝后,同一组的其他权限也相应的自动允许或者拒绝。

当targetSdkVersion/compileSdkVersion大于等于23时,我们用到危险权限时,应按照这样的逻辑去处理。先判断当前应用是否具有权限,如果没有就去申请,当用户允许或者拒绝后,会回调相应的方法,我们在回调中处理自己的逻辑。


申请单个权限

在Activity/Fragment中,判断是否具有权限的方法是 checkSelfPermission(),申请权限的方法是requestPermissions(),然后用户允许或者拒绝后会回调方法onRequestPermissionsResult()。
虽然Activity/Fragment提供了这些方法,如果我们用这些的话,要判断安卓版本是否大于等于23,代码如下: 
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
//动态请求权限

}else{
//直接去调用代码
}

 
谷歌工程师当然考虑到了这些,于是给开发者提供了兼容包,在Activity/Fragment中用ContextCompat.checkSelfPermission()判断是否具有权限;
在Activity中用 ActivityCompat.requestPermissions()请求权限;
在Fragment中直接用 requestPermissions()请求权限,不要在前面加上ActivityCompat,否则会回调Fragment所在Activity的回调方法;
在Activity/Fragment中用户允许或者拒绝权限后会回调onRequestPermissionsResult()方法。

下面看一个平常的调用系统相机拍照功能的代码:
private void takePhoto() {
Intent photoIn = new Intent(MediaStore.ACTION_IMAGE_CAPTURE);
startActivityForResult(photoIn, TAKE_PHOTO_REQUEST);
}

 
如果我们项目targetSdkVersion/compileSdkVersion大于等于23,那么就需要动态申请权限了:
if (ContextCompat.checkSelfPermission(MySetupActivity.this,  Manifest.permission.CAMERA)!=  PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(MySetupActivity.this,new String[]{Manifest.permission.CAMERA}, 100);
} else {
takePhoto();
}

 
先判断是否具有权限,如果有直接去执行相关代码,没有则去申请权限。
当用户点击允许或者拒绝权限时,会回调onRequestPermissionsResult方法,我们在此方法中进行处理:
@Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {

if (requestCode == 100) {//相机
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
takePhoto();
} else {
// Permission Denied
AlertDialog mDialog = new AlertDialog.Builder(MySetupActivity.this)
.setTitle("友好提醒")
.setMessage("您已拒绝权限,请开启权限!")
.setPositiveButton("开启", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
ShowAppSetDetails.showInstalledAppDetails(MySetupActivity.this, "user.zhuku.com");
LogPrint.logILsj(TAG, "开启权限设置");
}
})
.setCancelable(true)
.create();
mDialog.show();
}
}
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}

当用户允许权限后我们直接执行相关代码,若拒绝则提示用户,弹窗提示是否需要开启权限。其中的
ShowAppSetDetails.showInstalledAppDetails(MySetupActivity.this, "user.zhuku.com");

是开启当前app信息设置界面的代码。

具体代码如下:
import android.content.Context;
import android.content.Intent;
import android.net.Uri;
import android.os.Build;
import android.provider.Settings;
public class ShowAppSetDetails {
private static final String SCHEME = "package";
/**
* 调用系统InstalledAppDetails界面所需的Extra名称(用于Android 2.1及之前版本)
*/
private static final String APP_PKG_NAME_21 = "com.android.settings.ApplicationPkgName";
/**
* 调用系统InstalledAppDetails界面所需的Extra名称(用于Android 2.2)
*/
private static final String APP_PKG_NAME_22 = "pkg";
/**
* InstalledAppDetails所在包名
*/
private static final String APP_DETAILS_PACKAGE_NAME = "com.android.settings";
/**
* InstalledAppDetails类名
*/
private static final String APP_DETAILS_CLASS_NAME = "com.android.settings.InstalledAppDetails";

/**
* 调用系统InstalledAppDetails界面显示已安装应用程序的详细信息。 对于Android 2.3(Api Level
* 9)以上,使用SDK提供的接口; 2.3以下,使用非公开的接口(查看InstalledAppDetails源码)。
*
* @param context
* @param packageName 应用程序的包名
*/
public static void showInstalledAppDetails(Context context, String packageName) {
Intent intent = new Intent();
final int apiLevel = Build.VERSION.SDK_INT;
if (apiLevel >= 9) { // 2.3(ApiLevel 9)以上,使用SDK提供的接口
intent.setAction(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts(SCHEME, packageName, null);
intent.setData(uri);
} else { // 2.3以下,使用非公开的接口(查看InstalledAppDetails源码)
// 2.2和2.1中,InstalledAppDetails使用的APP_PKG_NAME不同。
final String appPkgName = (apiLevel == 8 ? APP_PKG_NAME_22
: APP_PKG_NAME_21);
intent.setAction(Intent.ACTION_VIEW);
intent.setClassName(APP_DETAILS_PACKAGE_NAME,
APP_DETAILS_CLASS_NAME);
intent.putExtra(appPkgName, packageName);
}
context.startActivity(intent);
}
}

当app申请权限时,如果用户点击了“不再提醒”,则会直接回调拒绝权限,为此谷歌工程师提供了shouldShowRequestPermissionRationale()方法。兼容包中方法是ActivityCompat.shouldShowRequestPermissionRationale(),如果是在Fragment中使用请直接用shouldShowRequestPermissionRationale()。

ActivityCompat.shouldShowRequestPermissionRationale()方法返回值是boolean类型,当第一次申请权限时,此方法会返回false,如果用户点击“不再提醒”,则此方法会返回true。
 
详细代码如下:
if (ContextCompat.checkSelfPermission(MySetupActivity.this, Manifest.permission.CAMERA)
!= PackageManager.PERMISSION_GRANTED) {
if (ActivityCompat.shouldShowRequestPermissionRationale(MySetupActivity.this, Manifest.permission.CAMERA)) {
//已经禁止提示了
mDialog = new AlertDialog.Builder(MySetupActivity.this)
.setTitle("友好提醒")
.setMessage("您已拒绝相机权限,此功能需要开启,是否开启?")
.setPositiveButton("是", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
ActivityCompat.requestPermissions(MySetupActivity.this,
new String[]{Manifest.permission.CAMERA},
100);
}
})
.setNegativeButton("否", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setCancelable(true)
.create();
mDialog.show();
} else {
ActivityCompat.requestPermissions(MySetupActivity.this,
new String[]{Manifest.permission.CAMERA},
100);
}

} else {
takePhoto();
}

 
如果是在Fragment中,则代码如下:
if (ContextCompat.checkSelfPermission(getActivity(), Manifest.permission.CAMERA)
!= PackageManager.PERMISSION_GRANTED) {
if (shouldShowRequestPermissionRationale(Manifest.permission.CAMERA)) {
//已经禁止提示了
mDialog = new AlertDialog.Builder(getContext())
.setTitle("友好提醒")
.setMessage("您已拒绝相机权限,此功能需要开启,是否开启?")
.setPositiveButton("是", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
requestPermissions(new String[]{Manifest.permission.CAMERA},
PERMISSIONS_CAMERA);
}
})
.setNegativeButton("否", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
}
})
.setCancelable(true)
.create();
mDialog.show();
} else {
requestPermissions(new String[]{Manifest.permission.CAMERA},
PERMISSIONS_CAMERA);
}

} else {
selectPicFromCamera();
}

特别要注意的是,如果在Fragment中请求权限,若在Activity中也重写了onRequestPermissionsResult(),则onRequestPermissionsResult()方法中一定要写
  super.onRequestPermissionsResult(requestCode, permissions, grantResults);

这句代码,若不写,则Activity不会分发执行Fragment中的权限回调方法。

因为Fragment中requestPermissions()源码如下:
public final void requestPermissions(@NonNull String[] permissions, int requestCode) {
if (mHost == null) {
throw new IllegalStateException("Fragment " + this + " not attached to Activity");
}
mHost.onRequestPermissionsFromFragment(this, permissions, requestCode);
}

其实在Fragment请求权限也是在它Activity中请求,只是把回调结果传递给了Fragment。


一次申请多个权限

例如需要申请的权限如下:
    /**
* 需要进行检测的权限数组
*/
protected String[] permissionList = {
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_LOCATION_EXTRA_COMMANDS,
Manifest.permission.READ_PHONE_STATE,
Manifest.permission.CAMERA,
Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE
};

 
我们要先判断每一个权限是否已经允许或者拒绝,当有某一个权限未被允许时,则申请未被允许的权限。
protected void onStart() {
super.onStart();

if (PermissionUtils.checkSelfPermission(SplashActivity.this, permissionList)) {
PermissionUtils.checkPermissions(this, 0, permissionList);
} else {
//处理业务逻辑
}

}

其中PermissionUtils类的代码如下:
import android.app.Activity;
import android.content.Context;
import android.content.pm.PackageManager;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;

import java.util.ArrayList;
import java.util.List;

public class PermissionUtils {
/**
* 检查权限
*/
public static void checkPermissions(Activity activity, int permissRequestCode, String... permissions) {
List<String> needRequestPermissonList = findDeniedPermissions(activity, permissions);
if (null != needRequestPermissonList
&& needRequestPermissonList.size() > 0) {
ActivityCompat.requestPermissions(activity,
needRequestPermissonList.toArray(
new String[needRequestPermissonList.size()]),
permissRequestCode);
}
}

/**
* 获取权限中需要申请权限的列表
*/
public static List<String> findDeniedPermissions(Activity activity, String[] permissions) {
List<String> needRequestPermissonList = new ArrayList<String>();
for (String perm : permissions) {
if (ContextCompat.checkSelfPermission(activity,
perm) != PackageManager.PERMISSION_GRANTED) {
needRequestPermissonList.add(perm);
} else {
if (ActivityCompat.shouldShowRequestPermissionRationale(
activity, perm)) {
needRequestPermissonList.add(perm);
}
}
}
return needRequestPermissonList;
}

public static boolean checkSelfPermission(Context context, String[] permissions) {
for (String perm : permissions) {
if (ContextCompat.checkSelfPermission(context, perm) != PackageManager.PERMISSION_GRANTED) {
return true;
}
}
return false;
}

public static boolean checkSelfResult(int[] grantResults) {
for (int grantResult : grantResults) {
if (grantResult != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
return true;
}
}

 
onRequestPermissionsResult回调方法中则这样处理:
@Override
public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);

if (requestCode == 0) {
if (PermissionUtils.checkSelfResult(grantResults)) {
// Permission Granted
//处理业务逻辑
} else {
// Permission Denied

if (null == mDialog)
mDialog = new AlertDialog.Builder(SplashActivity.this)
.setTitle("友好提醒")
.setMessage("没有权限将不能更好的使用,请开启权限!")
.setPositiveButton("开启", new DialogInterface.OnClickListener() {
@Override
public void onClick(DialogInterface dialog, int which) {
dialog.cancel();
ShowAppSetDetails.showInstalledAppDetails(SplashActivity.this, "user.zhuku.com");
LogPrint.logILsj(TAG, "开启权限设置");
}
})
.setCancelable(false)
.create();

if (!mDialog.isShowing()) {
mDialog.show();
}
}
}
}

 
如果项目需要在页面可见时进行权限申请,请放在onStart()方法中,不要写在onResume()中。
可以想象一下,如果写在onResume()中,当用户同意了权限,则无碍,若是点击拒绝,则会回调权限拒绝的方法,这时系统申请权限的对话框消失不见,会再次调用onResume()请求权限显示对话框,若是还拒绝,则会再次调用onResume()方法,一直处于死循环。
因为系统请求权限的对话框其实一个开启了一个Activity。部分源码如下:  
 
 public final void requestPermissions(@NonNull String[] permissions, int requestCode) {
if (mHasCurrentPermissionsRequest) {
Log.w(TAG, "Can reqeust only one set of permissions at a time");
// Dispatch the callback with empty arrays which means a cancellation.
onRequestPermissionsResult(requestCode, new String[0], new int[0]);
return;
}
Intent intent = getPackageManager().buildRequestPermissionsIntent(permissions);
startActivityForResult(REQUEST_PERMISSIONS_WHO_PREFIX, intent, requestCode, null);
mHasCurrentPermissionsRequest = true;
}

至此,老司机本次发车已到终点,这一程体验,你还不会封装自己的运行时权限库吗?
 
 


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2 个评论

顶一个!
serge

serge 回复 beyond

谢谢大佬

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