Android6.0运行时权限的封装(参考郭神的视频总结的代码)

这篇博客的代码是看了郭神的视频后，整合知识点得出的。
郭神视频录播地址：http://edu.youkuaiyun.com/course/detail/3539

关于运行时权限的特点：

1. APP从低于6.0的版本升级上来时，原来拥有的权限默认允许。也就是说不用重新申请权限。
2. APP的targetSdkVersion版本低于6.0时，也不用获取运行时权限。

话不多说，马上来封装起来。

1.先建一个接口，用于监听用户是否允许我们所申请的权限

/**
 * 运行时权限接口
 */

public interface RuntimePermissionListener {

    /**
     * 允许所请求的全部权限
     */
    void onRuntimePermissionGranted();

    /**
     * 拒绝所请求的部分或全部权限
     */
    void onRuntimePermissionDenied(List<String> deniedPermission);
}

2.建一个ActivityCollector类。因为在申请权限的时候需要一个Activity对象，利用ActivityCollector类，每次获取栈顶的Activity传参进去，这样，即使不在Activity里面也可以调用申请对象的方法。这样还有应该好处就是，栈顶的Activity的优先级最高，不容易被系统回收。

/**
 *  Activity 栈
 */

public class ActivityCollector {
    private static List<Activity> activityList = new ArrayList<>();

    public static void addActivity(Activity activity){
        activityList.add(activity);
    }

    public static void removeActivity(Activity activity){
        activityList.remove(activity);
    }

    public static Activity getTopActivity(){
        if(activityList.isEmpty()){
            return null;
        }else {
            return activityList.get(activityList.size() - 1);
        }
    }

}

3.建一个BaseActivity。让BaseActivity继承Activity，这样的好处是对项目的扩展性较高。

public class BaseActivity extends AppCompatActivity {

    private static final int RUNTIME_PERMISSION_REQUEST_CODE = 1;
    private static RuntimePermissionListener mRuntimePermissionListener;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_base);
        ActivityCollector.addActivity(this);//进栈
    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        ActivityCollector.removeActivity(this);//出栈
    }

    public static void requestPermission(String[] permissions, RuntimePermissionListener listener){
        Activity topActivity = ActivityCollector.getTopActivity();
        if(topActivity == null){//如果连栈顶Activity都没有，也就没必要申请权限了
            return;
        }
        mRuntimePermissionListener = listener;
        List<String> deniedPermissionList = new ArrayList<>();
        for (String permission : permissions){
            if(ContextCompat.checkSelfPermission(topActivity,permission) != PackageManager.PERMISSION_GRANTED){
                deniedPermissionList.add(permission);
            }
        }
        if(deniedPermissionList.isEmpty()){
            //权限全部允许
            mRuntimePermissionListener.onRuntimePermissionGranted();
        }else {
            //权限没有被全部允许
            String[] deniedPermissionArray = deniedPermissionList.toArray(new String[deniedPermissionList.size()]);
            //请求未被允许的权限
            ActivityCompat.requestPermissions(topActivity,deniedPermissionArray,RUNTIME_PERMISSION_REQUEST_CODE);
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        switch (requestCode){
            case RUNTIME_PERMISSION_REQUEST_CODE:
                if(grantResults.length > 0){
                    List<String> deniedPermissions = new ArrayList<>();
                    for (int i = 0; i < grantResults.length; i++){
                        int grantResult = grantResults[i];
                        String permission = permissions[i];
                        if(grantResult != PackageManager.PERMISSION_GRANTED){
                            deniedPermissions.add(permission);
                        }
                    }
                    if(deniedPermissions.isEmpty()){
                        //允许所请求的全部权限
                        mRuntimePermissionListener.onRuntimePermissionGranted();
                    }else {
                        //拒绝所请求的部分或全部权限
                        mRuntimePermissionListener.onRuntimePermissionDenied(deniedPermissions);
                    }
                }
                break;
            default:
                break;
        }
    }
}

4.测试一下。无论是否在Activity里面，都可以申请权限。

 public void test_click(View v){
        BaseActivity.requestPermission(new String[]{Manifest.permission.CALL_PHONE,Manifest.permission.CAMERA}, new RuntimePermissionListener() {
            @Override
            public void onRuntimePermissionGranted() {
                Toast.makeText(MainActivity.this,"都允许了",Toast.LENGTH_SHORT).show();
            }

            @Override
            public void onRuntimePermissionDenied(List<String> deniedPermission) {
                for(String permission :deniedPermission){
                    Toast.makeText(MainActivity.this,"被拒绝了" + permission,Toast.LENGTH_SHORT).show();
                }
            }
        });
    }

如此一来，便大功告成。