Android——多线程编程练习题

随便选择两个城市作为预选旅游目标。实现两个独立的线程分别显示10次城市名，每次显示后休眠一段随机时间(1000ms以内)，哪个先显示完毕，就决定去哪个城市。分别用Runnable接口和Thread类实现。

layout文件：

 <?xml version="1.0" encoding="utf-8"?>
 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     android:paddingBottom="@dimen/activity_vertical_margin"
     android:paddingLeft="@dimen/activity_horizontal_margin"
     android:paddingRight="@dimen/activity_horizontal_margin"
     android:paddingTop="@dimen/activity_vertical_margin"
     tools:context="com.hanqi.testapp2.PractiseActivity4"
     android:orientation="vertical">

     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:id="@+id/tvw1"/>
     <TextView
         android:layout_width="match_parent"
         android:layout_height="wrap_content"
         android:id="@+id/tvw2"/>

     <Button
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:id="@+id/btt1"
         android:text="随机选择"
         android:onClick="btn_onClick"/>
 </LinearLayout>

java类：

 package com.hanqi.testapp2;

 import android.os.Bundle;
 import android.support.v7.app.AppCompatActivity;
 import android.view.View;
 import android.widget.Button;
 import android.widget.TextView;
 import android.widget.Toast;

 public class PractiseActivity4 extends AppCompatActivity {

     TextView tvw1;
     Button btt1;
     TextView tvw2;
     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.activity_practise4);
         tvw1 = (TextView)findViewById(R.id.tvw1);
         btt1 = (Button)findViewById(R.id.btt1);
         tvw2 = (TextView)findViewById(R.id.tvw2);
     }
     String c1 = "北京";
     String c2 = "上海";
     public void btn_onClick(View v)
     {
         //创建子线程1
        new Thread(){
            @Override
            public void run() {
                for (int i=0;i<20;i++)
                {
                    if(i%2==0)
                    {
                      c1="";
                    }
                    else
                    {
                      c1="北京";
                    }
                    runOnUiThread(new Runnable() {
                        @Override
                        public void run() {
                            tvw1.setText(c1);
                        }
                    });
                    //暂停
                    try {
                        Thread.sleep((int) (Math.random()*1000));
                    }
                   catch (Exception e)
                   {

                   }
                }
                runOnUiThread(new Runnable() {
                    @Override
                    public void run() {
                        Toast.makeText(PractiseActivity4.this, c1 + "循环完成", Toast.LENGTH_SHORT).show();
                    }
                });
            }
        }.start();
         //创建子线程2
         new Thread(){
             @Override
             public void run() {
                 for (int i=0;i<20;i++)
                 {
                     if(i%2==0)
                     {
                         c2="";
                     }
                     else
                     {
                         c2="上海";
                     }
                     runOnUiThread(new Runnable() {
                         @Override
                         public void run() {
                             tvw2.setText(c2);
                         }
                     });
                     //暂停
                     try {
                         Thread.sleep((int) (Math.random()*1000));
                     }
                     catch (Exception e)
                     {

                     }
                 }
                 runOnUiThread(new Runnable() {
                     @Override
                     public void run() {
                         Toast.makeText(PractiseActivity4.this, c2 + "循环完成", Toast.LENGTH_SHORT).show();
                     }
                 });
             }
         }.start();
     }

 }

随便选择两个城市作为预选旅游目标。实现两个独立的线程分别显示10次城市名，每次显示后休眠一段随机时间(1000ms以内)，哪个先显示完毕，就决定去哪个城市。分别用Runnable接口和Thread类实现。