[ANDROID]APP加载界面完毕时回调，onWindowFocusChanged的使用

package com.example.test_resume;

import android.app.Activity;
import android.os.Bundle;

/**
 * 在onWindowFocusChanged中操作可以有效避免第一次启动APP和每次从后台启动后加载弹窗时报错Unable to add window
 * --token null is not valid的bug
 * 
 * 
 * @author NULL
 * 
 */
public class MainActivity extends Activity {
    private boolean isFirstLaunch = false;
    private boolean isResume = false;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        isFirstLaunch = true;
    }

    @Override
    protected void onResume() {
        super.onResume();
        isResume = true;
    }

    @Override
    public void onWindowFocusChanged(boolean hasFocus) {
        super.onWindowFocusChanged(hasFocus);
        if (hasFocus) {
            if (isFirstLaunch) {
                isFirstLaunch = false;
                // TODO 第一次启动界面加载完毕后的操作
            }
            if (isResume) {
                isResume = false;
                // TODO 每一次从后台打开后界面加载完毕后的操作
            }
        }
    }

    /**
     * 到后台时要移除添加window的操作
     */
    @Override
    protected void onPause() {
        super.onPause();
    }
}