tabhost通过手势滑动切换activity

package com.mars.mp3player;

import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.util.Log;
import android.view.GestureDetector;
import android.view.GestureDetector.SimpleOnGestureListener;
import android.view.Menu;
import android.view.MotionEvent;
import android.view.View;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;

public class ActivityMain extends TabActivity {
	private TabSpec tabSpec;
	private TabHost tabHost;
	private Intent intent;
	private static final int SWIPE_MIN_DISTANCE = 120;
	private static final int SWIPE_MAX_OFF_PATH = 250;
	private static final int SWIPE_THRESHOLD_VELOCITY = 200;
	private GestureDetector gestureDetector;
	View.OnTouchListener gestureListener;

	int currentView = 0;
	private static int maxTabIndex = 2;

	@Override
	public void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		super.setContentView(R.layout.activity_main);
		UtilVar.activities.add(ActivityMain.this);
		this.initTableHost();

		gestureDetector = new GestureDetector(new MyGestureDetector());
		gestureListener = new View.OnTouchListener() {
			public boolean onTouch(View v, MotionEvent event) {
				if (gestureDetector.onTouchEvent(event)) {
					return true;
				}
				return false;
			}
		};

	}

	/**
	 * tablehost的初始化，代码完成
	 */
	private void initTableHost() {
		tabHost = super.getTabHost();
		// 歌曲列表
		intent = new Intent(ActivityMain.this, ActivityList.class);
		tabSpec = tabHost
				.newTabSpec("歌曲列表")
				.setIndicator("歌曲列表",
						getResources().getDrawable(R.drawable.ic_launcher))
				.setContent(intent);
		tabHost.addTab(tabSpec);
		// 正在播放
		intent = new Intent(ActivityMain.this, ActivityPlaying.class);
		tabSpec = tabHost
				.newTabSpec("正在播放")
				.setIndicator("正在播放",
						getResources().getDrawable(R.drawable.ic_launcher))
				.setContent(intent);
		tabHost.addTab(tabSpec);
		// 专辑列表
		intent = new Intent(ActivityMain.this, ActivityLyric.class);
		tabSpec = tabHost
				.newTabSpec("歌词显示")
				.setIndicator("歌词显示",
						getResources().getDrawable(R.drawable.ic_launcher))
				.setContent(intent);
		tabHost.addTab(tabSpec);
		// 设置当前tab
		tabHost.setCurrentTab(1);
	}

	// 左右滑动刚好页面也有滑动效果
	class MyGestureDetector extends SimpleOnGestureListener {
		@Override
		public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
				float velocityY) {
			TabHost tabHost = getTabHost();
			try {
				if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
					return false;
				// right to left swipe
				if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
						&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
					Log.i("test", "right");
					if (currentView == maxTabIndex) {
						currentView = 0;
					} else {
						currentView++;
					}
					tabHost.setCurrentTab(currentView);
				} else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
						&& Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
					Log.i("test", "left");
					if (currentView == 0) {
						currentView = maxTabIndex;
					} else {
						currentView--;
					}
					tabHost.setCurrentTab(currentView);
				}
			} catch (Exception e) {
			}
			return false;
		}
	}

	@Override
	public boolean dispatchTouchEvent(MotionEvent event) {
		if (gestureDetector.onTouchEvent(event)) {
			event.setAction(MotionEvent.ACTION_CANCEL);
		}
		return super.dispatchTouchEvent(event);
	}

	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		getMenuInflater().inflate(R.menu.activity_main, menu);
		return true;
	}

}
// 主要代码就这样吧，以后就不必到处找手势跳转activity的例子了。