[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();
}
}