[转]Android定时刷新UI界面----Handler

本文转自：http://blog.csdn.net/macong01/article/details/7479266

本想做一个软件可以对UI界面进行定时更新，找了一些资料，先贴一个简单的定时更新界面程序，可以实现每隔1秒递增计数器的功能。

界面布局文件main.xml

<?xmlversion="1.0"encoding="utf-8"?>
<LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"android:layout_width="fill_parent"
    android:layout_height="fill_parent">
    <TextViewandroid:id="@+id/counter"android:layout_width="fill_parent"
        android:layout_height="wrap_content"android:text="Count: 0"/>
    <LinearLayoutandroid:orientation="horizontal"
        android:layout_width="fill_parent"android:layout_height="wrap_content">
        <Buttonandroid:text="start"android:id="@+id/Button01"
            android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"></Button>
        <Buttonandroid:text="stop"android:id="@+id/Button02"
            android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"android:enabled="false"></Button>
        <Buttonandroid:text="reset"android:id="@+id/Button03"
            android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"></Button>
    </LinearLayout>
</LinearLayout>

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
	android:orientation="vertical" android:layout_width="fill_parent"
	android:layout_height="fill_parent">
	<TextView android:id="@+id/counter" android:layout_width="fill_parent"
		android:layout_height="wrap_content" android:text="Count: 0" />
	<LinearLayout android:orientation="horizontal"
		android:layout_width="fill_parent" android:layout_height="wrap_content">
		<Button android:text="start" android:id="@+id/Button01"
			android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0"></Button>
		<Button android:text="stop" android:id="@+id/Button02"
			android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0" android:enabled="false"></Button>
		<Button android:text="reset" android:id="@+id/Button03"
			android:layout_width="fill_parent" android:layout_height="wrap_content" android:layout_weight="1.0"></Button>
	</LinearLayout>
</LinearLayout>

MyHandler.java

package com.scnu.mc.myhandler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

publicclass MyHandler extends Activity {
    private Button btnStart;
    private Button btnStop;
    private Button btnReset;
    private TextView tvCounter;
    privatelong count = 0;
    privateboolean run = false;

    privatefinal Handler handler = new Handler();

    privatefinal Runnable task = new Runnable() {

        @Override
        publicvoid run() {
            // TODO Auto-generated method stub
            if (run) {
                handler.postDelayed(this, 1000);
                count++;
            }
            tvCounter.setText("Count: " + count);
        }
    };

    /** Called when the activity is first created. */
    @Override
    publicvoid onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        btnStart = (Button) findViewById(R.id.Button01);
        btnStop = (Button) findViewById(R.id.Button02);
        btnReset = (Button) findViewById(R.id.Button03);
        tvCounter = (TextView) findViewById(R.id.counter);

        btnStart.setOnClickListener(new OnClickListener() {

            @Override
            publicvoid onClick(View v) {
                // TODO Auto-generated method stub
                run = true;
                updateButton();
                handler.postDelayed(task, 1000);
            }
        });

        btnStop.setOnClickListener(new OnClickListener() {

            @Override
            publicvoid onClick(View v) {
                // TODO Auto-generated method stub
                run = false;
                updateButton();
                handler.post(task);
            }
        });

        btnReset.setOnClickListener(new OnClickListener() {

            @Override
            publicvoid onClick(View v) {
                // TODO Auto-generated method stub
                count = 0;
                run = false;
                updateButton();
                handler.post(task);
            }
        });
    }

    privatevoid updateButton() {
        btnStart.setEnabled(!run);
        btnStop.setEnabled(run);
    }
}

package com.scnu.mc.myhandler;

import android.app.Activity;
import android.os.Bundle;
import android.os.Handler;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.TextView;

public class MyHandler extends Activity {
	private Button btnStart;
	private Button btnStop;
	private Button btnReset;
	private TextView tvCounter;
	private long count = 0;
	private boolean run = false;

	private final Handler handler = new Handler();

	private final Runnable task = new Runnable() {

		@Override
		public void run() {
			// TODO Auto-generated method stub
			if (run) {
				handler.postDelayed(this, 1000);
				count++;
			}
			tvCounter.setText("Count: " + count);
		}
	};

	/** Called when the activity is first created. */
	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);

		btnStart = (Button) findViewById(R.id.Button01);
		btnStop = (Button) findViewById(R.id.Button02);
		btnReset = (Button) findViewById(R.id.Button03);
		tvCounter = (TextView) findViewById(R.id.counter);

		btnStart.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				run = true;
				updateButton();
				handler.postDelayed(task, 1000);
			}
		});

		btnStop.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				run = false;
				updateButton();
				handler.post(task);
			}
		});

		btnReset.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				count = 0;
				run = false;
				updateButton();
				handler.post(task);
			}
		});
	}

	private void updateButton() {
		btnStart.setEnabled(!run);
		btnStop.setEnabled(run);
	}
}