Android开发（22）--seekBar采用handler消息处理操作

本案例简单实现进度条可走，可拖拽的功能，下面请看源码：

布局文件：

<RelativeLayout 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=".MainActivity" >

    <SeekBar
        android:id="@+id/seekBar1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_alignParentTop="true" />

</RelativeLayout>

java文件：

package com.example.lession16_seekbar;

import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.app.Activity;
import android.view.Menu;
import android.widget.SeekBar;

public class MainActivity extends Activity {

	private SeekBar seekBar;

	private static final int MAX_PROGRESS =100;

	private int current_progress=10;

	private static final int PRO=1;

	private Handler handler;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);

		seekBar = (SeekBar) this.findViewById(R.id.seekBar1);

		seekBar.setMax(MAX_PROGRESS);

	/*	new Thread(new Runnable() {

			@Override
			public void run() {
				while(true){
					try {
						Thread.sleep(600);
						current_progress+=10;
						seekBar.setProgress(current_progress);
					} catch (InterruptedException e) {
						// TODO Auto-generated catch block
						e.printStackTrace();
					}
				}

			}
		}).start();*/

		handler = new Handler(){
			 @Override
			public void handleMessage(Message msg) {
				super.handleMessage(msg);

				switch (msg.what) {
				case PRO:
					  if(current_progress>=MAX_PROGRESS){

					  }else{
						  current_progress+=1;
						  seekBar.incrementProgressBy(1);

						  handler.sendEmptyMessageDelayed(PRO, 600);
					  }
					break;

				default:
					break;
				}
			}
		};

	 current_progress=current_progress>0?current_progress:0;
	 seekBar.setProgress(current_progress);

	 handler.sendEmptyMessage(PRO);

	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}

}

效果图（自动走）：