Android之Tab分页标签的实现方法--------采用ActivityGroup和GridView的结合

         在前面，已经介绍了TabActivity和TabHost的结合实现Tab分页的三种方式。这里，将讲到采用ActivityGroup和GridView的结合，实现Tab分页。其实，这和TabActivity和TabHost的结合差不多。只不过，是自己把Tab的头部（选项栏）和页面视图分开实现。Tab头部采用GridView来实现，子页面采用LinearLayout容器来实现。然后把每个子Activity作为一个View视图，装载到LinearLayout容器里面。你会发现LinearLayout不仅仅是布局容器，它还有许多妙用。

        实现讲解：

        1、主类继承ActivityGroup

        public class GridViewTabPage extends ActivityGroup

        2、 获取每个子页面的Activity视图

        Intent intent = new Intent(GridViewTabPage.this, Page1.class);

        subPageView = getLocalActivityManager().startActivity(
      "subPageView" + i, intent);

        3、加载到容器

        pageContainer.addView(subPageView .getDecorView(),
        LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);

 

         

                                                            

                                          

                                          

       1、布局XML文件：main.xml

        <?xml version="1.0" encoding="utf-8"?><LinearLayoutandroid:id="@+id/gridViewTab"android:layout_width="fill_parent"android:layout_height="fill_parent"xmlns:android="http://schemas.android.com/apk/res/android"android:orientation="vertical"><GridViewandroid:id="@+id/gv_tabPage"android:layout_width="fill_parent"android:layout_height="wrap_content"android:numColumns="3"></GridView><LinearLayoutandroid:id="@+id/pageContainer"android:layout_below="@+id/gvTopBar" android:layout_width="fill_parent"android:layout_height="fill_parent"></LinearLayout></LinearLayout>

       2、代码文件：

        图片适配器：ImageAdapter.java

         package com.myandroid.test;import android.content.Context;import android.graphics.Color;import android.util.Log;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.GridView;import android.widget.ImageView;public class ImageAdapter extends BaseAdapter {private Context context;private int width;private int height;private ImageView[] imageViews;private Integer[] imgeIDs;public ImageAdapter(Context context, Integer[] imageIDs, int width, int height) {this.context = context;this.imgeIDs = imageIDs;this.width = width;this.height = height;imageViews = new ImageView[imageIDs.length];for(int i = 0; i < imageViews.length; i++) {imageViews[i] = new ImageView(context);}}public int getCount() {// TODO Auto-generated method stubreturn imgeIDs.length;}public Object getItem(int position) {// TODO Auto-generated method stubreturn position;}public long getItemId(int position) {// TODO Auto-generated method stubreturn position;} /** * 点击设置 * @param selectedID */public void setFocus(int selectedID) {Log.e("Seqence", "setFocus");for(int i = 0; i < imageViews.length; i++) {imageViews[i].setBackgroundColor(Color.BLACK);}imageViews[selectedID].setBackgroundColor(Color.YELLOW);}/** * 图片设置 */public View getView(int position, View convertView, ViewGroup parent) {// TODO Auto-generated method stubLog.e("Seqence", "getView");imageViews[position].setImageResource(imgeIDs[position]);imageViews[position].setLayoutParams(new GridView.LayoutParams(width, height));imageViews[position].setBackgroundColor(android.R.drawable.picture_frame);return imageViews[position];}}

         主文件：GridViewTabPage.java

         package com.myandroid.test;import android.app.ActivityGroup;import android.content.Intent;import android.graphics.Color;import android.graphics.drawable.ColorDrawable;import android.os.Bundle;import android.util.Log;import android.view.Gravity;import android.view.View;import android.view.Window;import android.view.ViewGroup.LayoutParams;import android.widget.AdapterView;import android.widget.GridView;import android.widget.LinearLayout;import android.widget.AdapterView.OnItemClickListener;public class GridViewTabPage extends ActivityGroup {private GridView gv_tabPage;//顶部Tab标签private ImageAdapter imageAdapter;//图片适配器public LinearLayout pageContainer;// 放置子页面的容器private Intent[] intents;//页面跳转Intentprivate Window[] subPageView;//子页面视图Viewprivate Integer[] tabImages = { R.drawable.a1,//tab标签图标R.drawable.a2, R.drawable.a3,};@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setContentView(R.layout.main);Log.e("Sequence", "start");//测试用gv_tabPage = (GridView) findViewById(R.id.gv_tabPage);gv_tabPage.setNumColumns(tabImages.length);// 设置列数gv_tabPage.setSelector(new ColorDrawable(Color.TRANSPARENT));// 选中的时候为透明色gv_tabPage.setGravity(Gravity.CENTER);// 位置居中gv_tabPage.setVerticalSpacing(0);// 垂直间隔int width = this.getWindowManager().getDefaultDisplay().getWidth()//获取屏幕宽度/ tabImages.length;//平分宽度imageAdapter = new ImageAdapter(this, tabImages, width, 48);//创建图片适配器，传递图片所需高和宽gv_tabPage.setAdapter(imageAdapter);// 设置菜单Adaptergv_tabPage.setOnItemClickListener(new ItemClickEvent()); //注册点击事件pageContainer = (LinearLayout) findViewById(R.id.pageContainer);SwitchPage(0);//默认打开第0页Log.e("Sequence", "end");}class ItemClickEvent implements OnItemClickListener {public void onItemClick(AdapterView<?> arg0, View arg1, int arg2,long arg3) {SwitchPage(arg2); //arg2表示选中的Tab标签号，从0~2}}/** * 用于获取intent和pageView， * 类似于单例模式，使得对象不用重复创建，同时，保留上一个对象的状态 * 当重新访问时，仍保留原来数据状态，如文本框里面的值。 * @param pageID 选中的tab序号（0~2） * @return */private Window getPageView(int pageID) {if(intents == null) {intents = new Intent[3];subPageView = new Window[3];intents[0] = new Intent(GridViewTabPage.this, Page1.class);intents[1] = new Intent(GridViewTabPage.this, Page2.class);intents[2] = new Intent(GridViewTabPage.this, Page3.class);for(int i = 0; i < 3; i++) {subPageView[i] = getLocalActivityManager().startActivity("subPageView" + i, intents[i]);}Log.e("New", "new");}return subPageView[pageID];}/** * 根据ID打开指定的PageActivity * @param id 选中项的tab序号 */private void SwitchPage(int id){pageContainer.removeAllViews();//必须先清除容器中所有的ViewimageAdapter.setFocus(id);Window pageView = null;switch(id){//获取子页面Viewcase 0:pageView = getPageView(0);break;case 1:pageView = getPageView(1);break;case 2:pageView = getPageView(2);break;default:break;} //装载子页面View到LinearLayout容器里面pageContainer.addView(pageView.getDecorView(),LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT);}}

         3、最后是在AndroidManifest.xml里添加Activity注册信息

         <?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="com.myandroid.test" android:versionCode="1" android:versionName="1.0"> <application android:icon="@drawable/icon" android:label="@string/app_name"> ................ <!-- 要添加Activity的声明，否则系统找不到文件报错 --><activity android:name="Page1"></activity><activity android:name="Page2"></activity><activity android:name="Page3"></activity> </application></manifest>

          同样的，对于Tab选项过多，可以采用Grally+ActivityGroup结合的实现方式。具体实现方法，和ActivityGroup和GridView的结合差不多，读者可以自己实现。