Android入门之SeekBar

效果图：（可自由滑动）

<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/firstSeekBar"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:max="100"
        />
</RelativeLayout>

package com.jkxqj.helloandroid;

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

public class MainActivity extends Activity {

	private SeekBar seekBar;
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		seekBar = (SeekBar)findViewById(R.id.firstSeekBar);
		seekBar.setProgress(30);
		seekBar.setSecondaryProgress(50);
		
		SeekBarListener listener = new SeekBarListener();
		seekBar.setOnSeekBarChangeListener(listener);
	}
	
	class SeekBarListener implements OnSeekBarChangeListener{

		/**
		 * seekBar 该对象指的是触发了监听器的SeekBar对象
		 * progress 指的是当前SeekBar的进度
		 */
		@Override
		public void onProgressChanged(SeekBar SeekBar, int progress, boolean fromUser) {
			System.out.println("progress:" + progress + ",fromUser:" + fromUser);
		}
		@Override
		public void onStartTrackingTouch(SeekBar seekBar) {
			System.out.println("onStart");
		}
		@Override
		public void onStopTrackingTouch(SeekBar seekBar) {
			System.out.println("onStop");
		}		
	}
	@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;
	}

}