Android 6.0起权限管理更严格了，朝着IOS权限靠拢了。看来Android也慢慢朝着封闭的方向发展了。如果 targetSdkVersion <23，就没有动态权限问题，但这不是长久之计，迟早要适配的。

Android将权限分为3种：

• 普通权限(Normal Permissions)
• 危险权限(Dangerous Permissions)
• 特殊权限(Special Permissions)

如果 targetSdkVersion>=23 那么就要对 危险权限和 特殊权限动态申请

危险权限(Dangerous Permissions)

危险权限基本都涉及到用户的隐私,Android系统将这些危险权限分为9组，

获取分组中某个权限的同时也就获取了同组中的其他权限

危险权限不仅需要在 AndroidManifest.xml中注册，还需要动态的申请权限

EasyPermisson 是Google对动态权限申请的封装，Google出品必属精品；

添加依赖

dependencies {compile 'pub.devrel:easypermissions:0.2.1'
}

AndroidManifest添加权限

<manifest>
<uses-permission android:name="android.permission.CAMERA" />
</manifest>

添加实现(以相机权限为例子)

public class MainActivity extends AppCompatActivity implements  EasyPermissions.PermissionCallbacks{private static final String TAG="tag";private static final int CAMERA_PERM = 0x100;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);grantCamera();}private void openCamera(){}@AfterPermissionGranted(CAMERA_PERM)private void grantCamera() {if (EasyPermissions.hasPermissions(MainActivity.this, Manifest.permission.CAMERA)) {//有此权限openCamera();} else {//没有此权限，需要重新申请EasyPermissions.requestPermissions(this, "请求camera权限", CAMERA_PERM, Manifest.permission.CAMERA);}}@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);EasyPermissions.onRequestPermissionsResult(requestCode, permissions, grantResults, this);}@Overridepublic void onPermissionsGranted(int requestCode, List<String> perms) {Log.d(TAG,"success");}@Overridepublic void onPermissionsDenied(int requestCode, List<String> perms) {if (EasyPermissions.somePermissionPermanentlyDenied(this, perms)) {new AppSettingsDialog.Builder(this, "点击确定去设置界面设置权限").setTitle("Title").setPositiveButton("确定").setNegativeButton("取消", null /* click listener */).setRequestCode(requestCode).build().show();}}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == CAMERA_PERM) {//从设置权限界面返回if (EasyPermissions.hasPermissions(MainActivity.this, Manifest.permission.CAMERA)){}}}
}

@AfterPermissionGranted(CAMERA_PERM)注解是在用户同意授权后EasyPermissions再次回调注解的函数；AppSettingsDialog 是googgle封装的直接跳转到设置权限界面dialog;

特殊权限(Special Permissions)

特殊权限比危险权限更危险，特殊权限需要在manifest中申请并且通过发送Intent让用户在设置界面进行勾选.

public class MainActivity extends AppCompatActivity implements  EasyPermissions.PermissionCallbacks{private static final int SYSTEM_ALERT_WINDOW_PERM = 0x101;private static final int WRITE_SETTINGS_PERM = 0x102;@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);grantAlertWindow();grantWriteSettings();}private void grantAlertWindow(){Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION);intent.setData(Uri.parse("package:" + getPackageName()));startActivityForResult(intent, SYSTEM_ALERT_WINDOW_PERM);}private void grantWriteSettings(){Intent intent = new Intent(Settings.ACTION_MANAGE_WRITE_SETTINGS);intent.setData(Uri.parse("package:" + getPackageName()));startActivityForResult(intent, WRITE_SETTINGS_PERM );}@Overrideprotected void onActivityResult(int requestCode, int resultCode, Intent data) {super.onActivityResult(requestCode, resultCode, data);if (requestCode == SYSTEM_ALERT_WINDOW_PERM) {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {if ( Settings.canDrawOverlays(this)){//get}}}else if (requestCode == WRITE_SETTINGS_PERM) {if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {if (Settings.System.canWrite(this)) {//get}}}}
}