消息机制及按钮实效性

三按钮的控制及实效。

<?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.example.wang.testapp2.TestActivity6"
    android:orientation="vertical">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="10"
        android:id="@+id/tv_6"
        android:layout_gravity="center"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="增加"
        android:onClick="bt3_OnClick"
        android:id="@+id/bt_3"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="减少"
        android:onClick="bt3_OnClick"
        android:id="@+id/bt_4"/>

    <Button
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="暂停"
        android:onClick="bt3_OnClick"
        android:id="@+id/bt_5"/>

</LinearLayout>

package com.example.wang.testapp2;

import android.os.Handler;
import android.os.Message;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.Toast;
import java.util.Random;


public class TestActivity6 extends AppCompatActivity {

    TextView tv_6;
    Button bt_3,bt_4,bt_5;

    //定义Handler

    int i=10;

    Handler hl=new Handler()

    {
        @Override
        public void handleMessage(Message msg) {
            super.handleMessage(msg);




            switch (msg.what)
            {

                case 1:

                    bt_3.setEnabled(false);
                    bt_4.setEnabled(true);
                    bt_5.setEnabled(true);

                    if (i==20)
                    {
                        bt_5.setEnabled(false);
                        return;
                    }

                    i++;


                    tv_6.setText(i+"");

                    //发送
                    hl.sendEmptyMessageDelayed(1,1000);

                    hl.removeMessages(2);

                    break;

                case 2:

                    bt_3.setEnabled(true);
                    bt_4.setEnabled(false);
                    bt_5.setEnabled(true);

                    if (i==1)
                    {

                        bt_5.setEnabled(false);
                        return;
                    }

                    i--;


                    tv_6.setText(i+"");

                    //发送
                    hl.sendEmptyMessageDelayed(2,1000);

                    hl.removeMessages(1);

                    break;

                case 3:
                    bt_3.setEnabled(true);
                    bt_4.setEnabled(true);
                    bt_5.setEnabled(false);

                    hl.removeMessages(1);
                    hl.removeMessages(2);

                    break;


            }
        }
    };

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_test6);

    
        tv_6=(TextView)findViewById(R.id.tv_6);
        bt_3=(Button)findViewById(R.id.bt_3);
        bt_4=(Button)findViewById(R.id.bt_4);
        bt_5=(Button)findViewById(R.id.bt_5);


        bt_3.setEnabled(true);
        bt_4.setEnabled(true);
        bt_5.setEnabled(false);
    }

    //3个按钮
    public  void bt3_OnClick(View v)
    {

        switch (v.getId())
        {
            case  R.id.bt_3:

                //发送增加消息
                hl.sendEmptyMessage(1);

                break;

            case  R.id.bt_4:

                //发送减少消息
                hl.sendEmptyMessage(2);

                break;

            case  R.id.bt_5:

                //发送暂停消息
                hl.sendEmptyMessage(3);


                break;
        }

    }
}