活动的启动模式一共有四种,分别是standard,singleTop,singleTask和singleInstance,可以在AndroidManifest.xml中通过给activity标签指定android:launchMode属性来选择启动模式,默认是standard模式。
standard模式下,如果重复创建同样的活动时,返回栈中也会存在三个活动的实例,此时需要按三次Back键才能退出程序。
出于这种情况用一个专门的集合类对所有的活动进行管理。
1.新建一个ActivityCollector.java作为活动管理器:
package com.imooc.sample;
import android.app.Activity;
import java.util.ArrayList;
import java.util.List;
/**
* 活动管理器
* Created by lsk on 2017/1/14.
*/
public class ActivityCollector {
public static List<Activity>activities=new ArrayList<Activity>();
public static void addActivity(Activity activity){
activities.add(activity);
}
public static void removeActivity(Activity activity){
activities.remove(activity);
}
//测试finishAll()方法在ThirdActivity中
public static void finishAll(){
for (Activity activity:activities) {
if(!activity.isFinishing()){
activity.finish();
}
}
}
}
2.新建BaseActivity继承Activity:
package com.imooc.sample;
import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
/**
*
* Created by lsk on 2017/1/14.
*/
public class BaseActivity extends Activity{
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("BaseActivity",getClass().getSimpleName());
ActivityCollector.addActivity(this);//向List添加活动
}
@Override
protected void onDestroy() {
super.onDestroy();
ActivityCollector.removeActivity(this);//从List移除活动
}
}
3.ThirdActivity中继承BaseActivity类,实现OnClickListener接口,在按钮点击事件中添加一行代码:ActivityCollector.finishAll();//销毁所有活动:
package com.imooc.sample;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.view.Window;
import android.widget.Button;
public class ThirdActivity extends BaseActivity implements View.OnClickListener{
//如果启动ThirdActivity需要两个参数,封装一个方法使ThirdActivity所需要的数据全部都在方法参数中体现出来了
public static void actionStart(Context context,String data1,String data2){
Intent intent=new Intent(context,ThirdActivity.class);
intent.putExtra("param1",data1);
intent.putExtra("param2",data2);
context.startActivity(intent);
}
private Button btn_test;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);//去掉标题栏
setContentView(R.layout.activity_third);
Button btn_exit=(Button) findViewById(R.id.btn_exit);
btn_exit.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
ActivityCollector.finishAll();//销毁所有活动
}
});
btn_test.setOnClickListener(this);
}
@Override
public void onClick(View v) {
switch (v.getId()){
case R.id.btn_test:
//添加逻辑代码
break;
default:
break;
}
}
}