[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

1. <?xmlversion="1.0"encoding="utf-8"?>
2. <LinearLayoutxmlns:android="http://schemas.android.com/apk/res/android"
3. android:orientation="vertical"android:layout_width="fill_parent"
4. android:layout_height="fill_parent">
5. <TextViewandroid:id="@+id/counter"android:layout_width="fill_parent"
6. android:layout_height="wrap_content"android:text="Count: 0"/>
7. <LinearLayoutandroid:orientation="horizontal"
8. android:layout_width="fill_parent"android:layout_height="wrap_content">
9. <Buttonandroid:text="start"android:id="@+id/Button01"
10. android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"></Button>
11. <Buttonandroid:text="stop"android:id="@+id/Button02"
12. android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"android:enabled="false"></Button>
13. <Buttonandroid:text="reset"android:id="@+id/Button03"
14. android:layout_width="fill_parent"android:layout_height="wrap_content"android:layout_weight="1.0"></Button>
15. </LinearLayout>
16. </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

1. package com.scnu.mc.myhandler;
2. import android.app.Activity;
3. import android.os.Bundle;
4. import android.os.Handler;
5. import android.view.View;
6. import android.view.View.OnClickListener;
7. import android.widget.Button;
8. import android.widget.TextView;
9. publicclass MyHandler extends Activity {
10. private Button btnStart;
11. private Button btnStop;
12. private Button btnReset;
13. private TextView tvCounter;
14. privatelong count = 0;
15. privateboolean run = false;
16. privatefinal Handler handler = new Handler();
17. privatefinal Runnable task = new Runnable() {
18. @Override
19. publicvoid run() {
20. // TODO Auto-generated method stub
21. if (run) {
22. handler.postDelayed(this, 1000);
23. count++;
24. }
25. tvCounter.setText("Count: " + count);
26. }
27. };
28. /** Called when the activity is first created. */
29. @Override
30. publicvoid onCreate(Bundle savedInstanceState) {
31. super.onCreate(savedInstanceState);
32. setContentView(R.layout.main);
33. btnStart = (Button) findViewById(R.id.Button01);
34. btnStop = (Button) findViewById(R.id.Button02);
35. btnReset = (Button) findViewById(R.id.Button03);
36. tvCounter = (TextView) findViewById(R.id.counter);
37. btnStart.setOnClickListener(new OnClickListener() {
38. @Override
39. publicvoid onClick(View v) {
40. // TODO Auto-generated method stub
41. run = true;
42. updateButton();
43. handler.postDelayed(task, 1000);
44. }
45. });
46. btnStop.setOnClickListener(new OnClickListener() {
47. @Override
48. publicvoid onClick(View v) {
49. // TODO Auto-generated method stub
50. run = false;
51. updateButton();
52. handler.post(task);
53. }
54. });
55. btnReset.setOnClickListener(new OnClickListener() {
56. @Override
57. publicvoid onClick(View v) {
58. // TODO Auto-generated method stub
59. count = 0;
60. run = false;
61. updateButton();
62. handler.post(task);
63. }
64. });
65. }
66. privatevoid updateButton() {
67. btnStart.setEnabled(!run);
68. btnStop.setEnabled(run);
69. }
70. }

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);
	}
}