android 廣告位的Timer定時刷新和按鈕的浮動顯示(3秒消失)

最近做項目要做廣告位的展示，所以就簡單的做了這個小項目。

代碼很簡單：

1、實現功能代碼：

package com.my.zx;

import java.util.Timer;
import java.util.TimerTask;

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.os.Handler;
import android.os.Message;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageSwitcher;
import android.widget.ImageView;
import android.widget.LinearLayout.LayoutParams;
import android.widget.ViewSwitcher.ViewFactory;

/**
 * 
 * @author [email protected]
 *
 */
public class zx extends Activity {
    /** Called when the activity is first created. */
	
	private Context mActivity;
	private Timer adTimer;	
	private AdTimerTask adTask;
	private Timer hideTimer ;	
	private HideTimerTask hideTask; 
	
	private static final Integer[] imagelist = { R.drawable.new_home_normal, R.drawable.new_rank_normal, 
		R.drawable.new_user_normal, R.drawable.new_search_normal, R.drawable.new_manage_normal};
	
	private ImageSwitcher m_Switcher;
	private Button next, pre ;
	private static int index = 0;
	
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        mActivity = this;
        initAd();   
        hideTimer = new Timer(true);
        adTimer = new Timer(true);	//廣告的
        hideBtn();
    }
    
	private void initAd() {
		m_Switcher = (ImageSwitcher) findViewById(R.id.imageswitcher);
		m_Switcher.setFactory(new ViewFactoryImpl());
		m_Switcher.setOnTouchListener(new mSwitcherOnTouchListener());
		m_Switcher.setImageResource(imagelist[index]);
		// 因爲要旋轉所以我們需要保存視圖的緩存信息  
		m_Switcher.setPersistentDrawingCache(ViewGroup.PERSISTENT_ANIMATION_CACHE); 
		next = (Button) findViewById(R.id.next);	//下一張
		next.setOnClickListener(new OnClickListener() {	
			// 從右拖到左，即看後一張
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				btnNext();
			}
		});
		pre = (Button) findViewById(R.id.pre);
		pre.setOnClickListener(new OnClickListener() {
			//從左拖到右，看前一張
			@Override
			public void onClick(View v) {
				// TODO Auto-generated method stub
				btnPre();
			}
		});	
	}
	
	private class ViewFactoryImpl implements ViewFactory {

		@Override
		public View makeView() {
			// TODO Auto-generated method stub
			// 實例化圖片顯示
			ImageView img = new ImageView(mActivity); 
			// 設置背景顏色
			img.setBackgroundColor(0xFFFFFFFF); 
			// 居中顯示
			img.setScaleType(ImageView.ScaleType.CENTER); 
			// 自適應圖片大小
			//image.setMinimumHeight(200); 
			//image.setMinimumWidth(200); 
			img.setLayoutParams(new ImageSwitcher.LayoutParams( 
			LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT)); // 定義組件
			return img;
		}		
	}
	
	class mSwitcherOnTouchListener implements View.OnTouchListener {

		@Override
		public boolean onTouch(View v, MotionEvent event) {
			// TODO Auto-generated method stub
			switch (event.getAction()) {
				case MotionEvent.ACTION_DOWN:
					pre.setVisibility(View.VISIBLE);
					next.setVisibility(View.VISIBLE);
					if (adTimer != null) {
						if (adTask != null) {
							adTask.cancel();
						}
					}
					break;
				case MotionEvent.ACTION_UP:
					hideBtn();
					break;
				default :
					break;
			}	
			return true;
		}
	}
	
	private void hideBtn() {
		if (hideTimer != null){
			if (hideTask != null){
				hideTask.cancel();  //將原任務從隊列中移除
			}
		}
		hideTask = new HideTimerTask();
		hideTimer.schedule(hideTask, 3000); 
	}
	
	private void cancelAdTask() {		
		adTask = new AdTimerTask();
		adTimer.schedule(adTask, 3000, 3000);
	}
	
	
	class HideTimerTask extends TimerTask {

		@Override
		public void run() {
			// TODO Auto-generated method stub
			Message message = new Message();
			message.what = 1;
			handler.sendMessage(message);
		}		
	}
	
	Handler handler = new Handler(){
		public void handleMessage(Message msg) {
			switch (msg.what) {
			case 1:
				pre.setVisibility(View.GONE);
				next.setVisibility(View.GONE);
				cancelAdTask();
				break;
			case 2:
				//廣告頁刷新
				btnNext();
			default:
				break;
			}
		};
	};	 
	
	class AdTimerTask extends TimerTask {

		@Override
		public void run() {
			// TODO Auto-generated method stub
			Message message = new Message();
			message.what = 2;
			handler.sendMessage(message);
		}
		
	}
	
	private void btnNext() {
		index++;
		if (index >= imagelist.length) {
			index = 0;
		}
		m_Switcher.setImageResource(imagelist[index]);
	}
	
	private void btnPre() {
		index--;
		if (index < 0) {
			index = imagelist.length - 1;
		}
		m_Switcher.setImageResource(imagelist[index]);
	}
	
}

2、佈局main.xml

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="72.0sp" >	
	<ImageSwitcher android:id="@+id/imageswitcher" android:background="@drawable/ad_idex_imageswitcher_bg" android:layout_width="fill_parent" android:layout_height="72.0sp" android:layout_gravity="center" android:layout_marginLeft="5.0dip" android:layout_marginRight="5.0dip" android:layout_weight="1.0" />		
	<RelativeLayout android:layout_width="fill_parent" android:layout_height="72.0sp" >
		<Button android:id="@+id/pre" android:layout_width="wrap_content" android:layout_height="fill_parent" android:text="pre" android:layout_alignParentLeft="true" />
		<Button android:id="@+id/next" android:layout_width="wrap_content" android:layout_height="fill_parent" android:text="next" android:layout_alignParentRight="true" />
	</RelativeLayout>
</FrameLayout>

如上就是全部代碼：這裏要寫幾點注意的地方：

1、FrameLayout佈局中，誰在底部，就先佈局誰。

2、定時器Timer，我遇到了 java.lang.IllegalStateException: TimerTask is scheduled already。這個錯誤，這是由於每個TimerTask只能被schedule一次，第二次會拋出異常。

3、hideTimer.schedule(hideTask, 3000);   和  adTimer.schedule(adTask, 3000, 3000);的區別

第一種是:沒有設置延遲，也就是立即執行，以後每3000秒執行一次，相當於schedule(adTask, 0, 3000)

第二種是:延遲3000秒之後執行，以後每3000秒執行一次.

源代碼地址：源文件下載地址