开发一个相机应用，需要申请三个权限：相机、读文件、写文件。
1、在AndroidManifest.xml中添加
<uses-permission android:name="android.permission.CAMERA"/><uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/><uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE"/>
2、新建一个Permission类
public class Permission {public static final int REQUEST_CODE = 5;//定义三个权限private static final String[] permission = new String[]{Manifest.permission.CAMERA,Manifest.permission.READ_EXTERNAL_STORAGE,Manifest.permission.WRITE_EXTERNAL_STORAGE,};//每个权限是否已授public static boolean isPermissionGranted(Activity activity){if(Build.VERSION.SDK_INT >= 23){for(int i = 0; i < permission.length;i++) {int checkPermission = ContextCompat.checkSelfPermission(activity,permission[i]);/**** checkPermission返回两个值* 有权限: PackageManager.PERMISSION_GRANTED* 无权限: PackageManager.PERMISSION_DENIED*/if(checkPermission != PackageManager.PERMISSION_GRANTED){return false;}}return true;}else{return true;}}public static boolean checkPermission(Activity activity){if(isPermissionGranted(activity)) {return true;} else {//如果没有设置过权限许可，则弹出系统的授权窗口ActivityCompat.requestPermissions(activity,permission,REQUEST_CODE);return false;}}}
3、在MainActivity中加入授权操作
@Overrideprotected void onStart() {super.onStart();Permission.checkPermission(this);}@Overrideprotected void onResume() {super.onResume();if(Permission.isPermissionGranted(this)) {Log.i("PERMISSION","请求权限成功");}}
初步授权成功
4、在MainActivity中处理授权失败结果，拒绝授权则退出应用
@Overridepublic void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {super.onRequestPermissionsResult(requestCode, permissions, grantResults);if (requestCode == Permission.REQUEST_CODE) {for (int grantResult : grantResults) {if (grantResult != PackageManager.PERMISSION_GRANTED) {Log.e("Permission","授权失败！");// 授权失败，退出应用this.finish();return;}}}}
