仿android系统Launcher界面

写的我要吐血了。。。是不是我太菜了？

放出代码.....

res-->layout-->activity_main.xml

res-->layout-->labelicon.xml

res-->layout-->slidelistview.xml

res-->anim-->slide_in_right.xml

res-->anim-->slide_out_left.xml

MainActivity.java

package com.demo.viewswitcherdemo;

import java.util.ArrayList;

import android.os.Bundle;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.ViewSwitcher;
import android.widget.ViewSwitcher.ViewFactory;

public class MainActivity extends Activity {
	//定义一个常量，用于显示每屏显示的应用程序数
	public static final int NUMBER_PER_SCREEN = 12;
	//代表应用程序的内部类
	public static class DataItem{
		//应用程序名称
		public String dataName;
		//应用程序图标
		public Drawable drawable;
	}
	//保存系统所有应用程序的List集合
	private ArrayList items = new ArrayList();
	//记录当前正在显示第几屏的程序
	private int screenNo = -1;
	//保存程序所占的总屏数
	private int screenCount;
	
	ViewSwitcher switcher;
	//创建LayoutInflater对象
	LayoutInflater inflater;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		inflater = LayoutInflater.from(MainActivity.this);
		//创建一个包含40个元素的List集合，用于模拟包含40个应用程序
		for(int i=0; i<40; i++){
			String label = "" + i;
			Drawable drawable = getResources().getDrawable(R.drawable.ic_launcher);
			DataItem item = new DataItem();
			item.dataName = label;
			item.drawable = drawable;
			items.add(item);
		}
		//计算应用程序所占的总屏数
		//如果应用程序的数量能整除Number_per_screen,除法的结果就是总屏数
		//如果不能，总屏数应该是除法的结果再加1
		screenCount = items.size() % NUMBER_PER_SCREEN == 0 ? items.size() / NUMBER_PER_SCREEN: items.size() / NUMBER_PER_SCREEN + 1;
		switcher = (ViewSwitcher)findViewById(R.id.viewSwitcher);
		switcher.setFactory(new ViewFactory(){
			//实际上就是返回一个GridView组件
			@Override
			public View makeView() {
				//加载这个组件，实际上就是一个GridView组件
				return inflater.inflate(R.layout.slidelistview, null);
			}
			
		});
		//页面加载时先显示第一屏
		next(null);
	}
	public void next(View v){
		if(screenNo < screenCount - 1){
			screenNo++;
			//为ViewSwitcher的组件显示过程设置动画
			switcher.setInAnimation(this,R.anim.slide_in_right);
			//为ViewSwitcher的组件隐藏过程设置动画
			switcher.setOutAnimation(this,R.anim.slide_out_left);
			//控制下一屏将要显示的GridView对应的Adapter
			((GridView)switcher.getNextView()).setAdapter(adapter);
			switcher.showNext();
		}
	}
	public void prev(View v){
		if(screenNo > 0){
			screenNo--;
			//为ViewSwitcher的组件显示过程设置动画
			switcher.setInAnimation(this,R.anim.slide_out_left);
			//为ViewSwitcher的组件隐藏过程设置动画
			switcher.setOutAnimation(this,R.anim.slide_in_right);
			//控制下一屏将要显示的GridView对应的Adapter
			((GridView)switcher.getNextView()).setAdapter(adapter);
			switcher.showPrevious();
		}
		
	}
	//该BaseAdapter负责为每屏显示的GridView提供列表项
	private BaseAdapter adapter = new BaseAdapter(){

		@Override
		public int getCount() {
			// 如果已经到了最后一屏幕，且应用程序的数量不能整除Number_per_screen
			if(screenNo == screenCount -1 && items.size() % NUMBER_PER_SCREEN != 0){
				//最后一屏显示的程序数为应用程序的数量对number_per_screen求余
				return items.size() % NUMBER_PER_SCREEN;
			}
			//否则每屏显示的程序数量为Number_per_screen
			return NUMBER_PER_SCREEN;
		}

		@Override
		public DataItem getItem(int position) {
			// 根据screenNo计算第position个列表项的数据
			return items.get(screenNo * NUMBER_PER_SCREEN + position);
		}

		@Override
		public long getItemId(int position) {
			// TODO Auto-generated method stub
			return position;
		}

		@Override
		public View getView(int position, View convertView, ViewGroup parent) {
			View view = convertView;
			if(convertView == null){
				//加载R.layout.labelicon布局文件
				view = inflater.inflate(R.layout.labelicon, null);
			}
			//获取R.layout.labelicon布局文件中的ImageView组件，并为之设置图标
			ImageView imageView = (ImageView)view.findViewById(R.id.imageview);
			imageView.setImageDrawable(getItem(position).drawable);
			//获取Textview
			TextView textView = (TextView)view.findViewById(R.id.textview);
			textView.setText(getItem(position).dataName);
			return view;
		}};

	@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;
	}

}