Android 6.0以上动态获取权限

package com.example.tergun.retrfittest;

import android.Manifest;
import android.content.DialogInterface;
import android.content.pm.PackageManager;
import android.graphics.Color;
import android.support.v4.app.ActivityCompat;
import android.support.v4.content.ContextCompat;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.Toast;

public class Main2Activity extends AppCompatActivity {
    private final int CAMERA_REQUEST_CODE = 1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main2);
        requestPermission();
    }

    private void requestPermission() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
                != PackageManager.PERMISSION_GRANTED) {
            // 第一次请求权限时，用户如果拒绝，下一次请求shouldShowRequestPermissionRationale()返回true
            // 向用户解释为什么需要这个权限
            if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)) {
//                                //申请相机权限
                ActivityCompat.requestPermissions(Main2Activity.this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, CAMERA_REQUEST_CODE);
            } else {
                //申请相机权限
                ActivityCompat.requestPermissions(this,
                        new String[]{Manifest.permission.ACCESS_FINE_LOCATION}, CAMERA_REQUEST_CODE);
            }
        } else {
//            tvPermissionStatus.setTextColor(Color.GREEN);
//            tvPermissionStatus.setText("相机权限已申请");
            Toast.makeText(Main2Activity.this, "相机权限已申请", Toast.LENGTH_SHORT).show();
        }
    }

    @Override
    public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
        if (requestCode == CAMERA_REQUEST_CODE) {
            if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
                Toast.makeText(Main2Activity.this, "相机权限已申请", Toast.LENGTH_SHORT).show();
            } else {
                //用户勾选了不再询问
                //提示用户手动打开权限
                if (!ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.ACCESS_FINE_LOCATION)) {
                    Toast.makeText(this, "相机权限已被禁止", Toast.LENGTH_SHORT).show();
                }
            }
        }
    }

}