谈谈Android 6.0运行时权限理解

dangerous列表：

版本兼容

当然，谷歌也是考虑到如果是以API 23之前的版本编译的APP，在6.0的系统上运行，还是能兼容的。如果是23之前的版本编译的APP，则权限模型走的是老的模式，也就是在一条龙的模式，在manifest清单注册，系统会帮我们默认授权，并且也能运行。

但如果是以API 23的版本编译的APP，那走的的必须是新的权限模型，在遇到dangerous权限的时候，必须进行授权的，如果没有进行授权话，系统则会提示崩溃信息。所以，基于6.0系统的开发的程序， 在打开页面的时候，必须要考虑这个页面是否用到需要授权的权限，页面检测是否已经授权过了没。

实现方式

第一步：检测权限

// Assume thisActivity is the current activity  int permissionCheck = ContextCompat.checkSelfPermission(thisActivity,          Manifest.permission.WRITE_CALENDAR);

第二步：请求权限

// Here, thisActivity is the current activity  if (ContextCompat.checkSelfPermission(thisActivity,                  Manifest.permission.READ_CONTACTS)          != PackageManager.PERMISSION_GRANTED) {        // Should we show an explanation?      if (ActivityCompat.shouldShowRequestPermissionRationale(thisActivity,              Manifest.permission.READ_CONTACTS)) {            // Show an expanation to the user *asynchronously* -- don't block          // this thread waiting for the user's response! After the user          // sees the explanation, try again to request the permission.        } else {            // No explanation needed, we can request the permission.            ActivityCompat.requestPermissions(thisActivity,                  new String[]{Manifest.permission.READ_CONTACTS},                  MY_PERMISSIONS_REQUEST_READ_CONTACTS);            // MY_PERMISSIONS_REQUEST_READ_CONTACTS is an          // app-defined int constant. The callback method gets the          // result of the request.      }  }

第三步：处理权限请求结果

@Override  public void onRequestPermissionsResult(int requestCode,          String permissions[], int[] grantResults) {      switch (requestCode) {          case MY_PERMISSIONS_REQUEST_READ_CONTACTS: {              // If request is cancelled, the result arrays are empty.              if (grantResults.length > 0                  && grantResults[0] == PackageManager.PERMISSION_GRANTED) {                    // permission was granted, yay! Do the                  // contacts-related task you need to do.                } else {                    // permission denied, boo! Disable the                  // functionality that depends on this permission.              }              return;          }            // other 'case' lines to check for other          // permissions this app might request      }  }

“android.permission.SYSTEM_ALERT_WINDOW”

“android.permission.WRITE_SETTINGS”

Intent intent = new Intent(android.provider.Settings.ACTION_MANAGE_WRITE_SETTINGS);  intent.setData(Uri.parse("package:" + getPackageName()));  intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK);  startActivity(intent);