android學習---SeekBar和RatingBar

SeekBar 拖動條：拖動條和滾動條類似，當是拖動條可以拖動滑塊改變進度

RatingBar 星級評分條：星級評分條與拖動條相似

SeekBar特有的xml屬性

android:thumb 指定一個Arawable對象，作為之定義滑塊

RatingBar特有的xml屬性

android:isIndicator 是否允許用戶改變（true為不允許修改）

android:numStars 共有多少個星級

android:rating 默認的星級<喎?/kf/ware/vc/" target="_blank" class="keylink">vcD4KPHA+YW5kcm9pZDpzdGVwU2l6ZSAgIMO/tM7WwcnZuMSx5Lbgydm49tDHvLY8YnI+CjwvcD4KPHA+PGltZyBzcmM9"/uploadfile/Collfiles/20140805/20140805091211121.png" alt="\">

為了知道改變的進度而做相應的操作，我們需要添加監聽

SeekBar 的監聽 OnSeekBarChangeListener

RatingBar的監聽 OnRatingBarChangeListener

下面我們通過實例來熟悉它們

（1）編寫布局文件 activity_main.xml

(2)編寫 MainActivity.java

package com.example.bar;

import android.annotation.TargetApi;
import android.app.Activity;
import android.os.Build;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.widget.ImageView;
import android.widget.RatingBar;
import android.widget.RatingBar.OnRatingBarChangeListener;
import android.widget.SeekBar;
import android.widget.SeekBar.OnSeekBarChangeListener;

@TargetApi(Build.VERSION_CODES.HONEYCOMB)
public class MainActivity extends Activity {
	
	private ImageView imgViewSB = null; //定義ImageView
	private ImageView imgViewRB = null;
	private SeekBar seekBar = null;  //定義SeekBar
	private RatingBar ratingBar = null; //定義RatingBar

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		
		//布局組件
		this.imgViewSB = (ImageView) findViewById(R.id.imgView1);
		this.imgViewRB = (ImageView) findViewById(R.id.imgView2);
		this.seekBar = (SeekBar) findViewById(R.id.seekBar);
		this.ratingBar = (RatingBar) findViewById(R.id.reatingBar);
		
		//seekBar設置監聽，改變圖片透明度
		this.seekBar.setOnSeekBarChangeListener(new OnSeekBarChangeListener() {
			
			@Override
			public void onStopTrackingTouch(SeekBar seekBar) {
				Log.i("onStopTrackingTouch", "停止拖動觸發的方法");
				
			}
			
			@Override
			public void onStartTrackingTouch(SeekBar seekBar) {
				Log.i("onStartTrackingTouch", "開始拖動觸發的方法");
				
			}
			
			
			/**
			 * seekBar: SeekBar對象
			 * progress:拖動條的進度
			 * fromUser:是否用戶手動改變
			 */
			@Override
			public void onProgressChanged(SeekBar seekBar, int progress,
					boolean fromUser) {
				imgViewSB.setAlpha(progress);  //設置圖片的透明度
				Log.i("onProgressChanged", "拖動滑塊位置發生改變時觸發的方法");
				
			}
		});
		
		//ratingBar設置監聽，改變圖片透明度
		this.ratingBar.setOnRatingBarChangeListener(new OnRatingBarChangeListener() {
			
			
			/**
			 * ratingBar:RatingBar對象
			 * rating :星級的大小
			 * fromUser:是否用戶手動改變
			 */
			@Override
			public void onRatingChanged(RatingBar ratingBar, float rating,
					boolean fromUser) {
				imgViewRB.setAlpha((int)(rating*255/5));
				
			}
		});
		
		
	}

	@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;
	}

}

允許之後，效果如下：