Android学习之GroupActivity

实现菜单功能,其中定一个Gridview和一个LineaLayout 两个组建，其中同时用到了Dialog

其中，最重要的地方 有Adapter  和 切换图片对于Activity 需要继承为 ActivityGroup，才有获取getLocalActivityManager（）的方法

ContentActivity布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

	<ImageView
	    android:id="@+id/img"
	    android:layout_width="266dp"
	    android:layout_height="382dp"
	    android:src="@drawable/meinv" />

</LinearLayout>

MainActivity布局

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/LinearLayout1"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    tools:context=".MainActivity" >

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent" >
		<!-- 包含的内容 -->
        <LinearLayout
            android:id="@+id/content"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical" >
        </LinearLayout>
		 <!--
  	      	 定义整体的布局文件  
    		  定义工具栏
                    定义GridView 
        	android:layout_alignParentBottom 设定在底部对齐
        	android:fadingEdgeLength  标签褪色

        -->
        <GridView
            android:id="@+id/gridViewBar"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_alignParentBottom="true"
            android:fadingEdge="vertical"
            android:fadingEdgeLength="5sp" >
        </GridView>
    </RelativeLayout>

</LinearLayout>

MainActivity代码

package com.example.day09_09_activitygroup01;

import android.app.ActivityGroup;
import android.app.AlertDialog;
import android.app.Dialog;
import android.content.DialogInterface;
import android.content.Intent;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.os.Bundle;
import android.view.Gravity;
import android.view.KeyEvent;
import android.view.View;
import android.view.Window;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.GridView;
import android.widget.LinearLayout;
import android.widget.LinearLayout.LayoutParams;

public class MainActivity extends ActivityGroup {
	private GridView gridBar;
	private LinearLayout content;
	private MenuIMageAdapter adapter;
	// 定义数据
	private int[] img_data = new int[] { R.drawable.menu_main,
			R.drawable.menu_news, R.drawable.menu_contact,
			R.drawable.menu_more, R.drawable.menu_exit };
	private int width;
	private int height;
	private Intent intent;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		// 取消标题显示
		super.requestWindowFeature(Window.FEATURE_NO_TITLE);
		setContentView(R.layout.activity_main);
		// 获取屏幕的高宽
		width = super.getWindowManager().getDefaultDisplay().getWidth()
				/ this.img_data.length;
		// 高度用于显示GridView
		height = super.getWindowManager().getDefaultDisplay().getHeight() / 8;

		// 获取控件
		gridBar = (GridView) super.findViewById(R.id.gridViewBar);
		content = (LinearLayout) super.findViewById(R.id.content);

		// 设定GridView的每一列显示的个数
		gridBar.setNumColumns(img_data.length);
		// 设定为透明色
		gridBar.setSelector(new ColorDrawable(Color.TRANSPARENT));
		gridBar.setGravity(Gravity.CENTER);
		gridBar.setVerticalSpacing(0);

		// 设定Adapter
		adapter = new MenuIMageAdapter(MainActivity.this, img_data, width,
				height, 4);
		gridBar.setAdapter(adapter);

		// 跳转Activity
		gridBar.setOnItemClickListener(new ShowSub());
	}

	private class ShowSub implements OnItemClickListener {

		@Override
		public void onItemClick(AdapterView<?> parent, View view, int position,
				long id) {
			// TODO Auto-generated method stub
			MainActivity.this.switchActivity(position);
		}

	}

	private void switchActivity(int position) {
		adapter.setFocus(position);
		// 删除所有的Activity
		this.content.removeAllViews();
		// 跳转Activity
		switch (position) {
		case 0:
			intent = new Intent(MainActivity.this, SecondActivity.class);
			break;
		case 1:
			intent = new Intent(MainActivity.this, SecondActivity.class);
			break;
		case 2:
			intent = new Intent(MainActivity.this, SecondActivity.class);
			break;
		case 3:
			intent = new Intent(MainActivity.this, SecondActivity.class);
			break;
		case 4:
			MainActivity.this.showExitDialog();
			return;
		}
		// 转到一个Activty中
		intent.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
		// 创建window
		Window second = super.getLocalActivityManager().startActivity("second",
				intent);
		// 建立Window 顶端显示
		this.content.addView(second.getDecorView(), LayoutParams.MATCH_PARENT,
				LayoutParams.MATCH_PARENT);

	}

	public void showExitDialog() {
		Dialog dialog = new AlertDialog.Builder(MainActivity.this)
				.setTitle("退出").setMessage("确认退出")
				.setIcon(R.drawable.ic_launcher)
				.setNegativeButton("取消", new DialogInterface.OnClickListener() {

					@Override
					public void onClick(DialogInterface dialog, int which) {
						// TODO Auto-generated method stub
						dialog.dismiss();
					}
				})
				.setPositiveButton("确定", new DialogInterface.OnClickListener() {

					@Override
					public void onClick(DialogInterface dialog, int which) {
						// TODO Auto-generated method stub
						// 退出
						MainActivity.this.finish();
					}
				}).create();

		dialog.show();
	}

	@Override
	public boolean onKeyDown(int keyCode, KeyEvent event) {
		// TODO Auto-generated method stub
		if (keyCode == KeyEvent.KEYCODE_BACK) {
			MainActivity.this.showExitDialog();
		}
		return super.onKeyDown(keyCode, event);
	}

}

CotentActivity代码

package com.example.day09_09_activitygroup01;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;

public class SecondActivity extends Activity {
	//读取第二哥Activity
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_second);
	}
}

GridBarImageAdapter  最重要的

package com.example.day09_09_activitygroup01;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.ImageView;
import android.widget.LinearLayout.LayoutParams;

public class MenuIMageAdapter extends BaseAdapter {
	private ImageView [] imageViews = null;
	private Context context;
	private int  selected;
	
	/*
	 * Context用于接受上下文
	 * ImageView 用于接受传递过来的ImageView
	 * width 和height 用于计算Menu的显示高度
	 * selected 用于设定当Menu选中的时候，设定背景
	 */
	public MenuIMageAdapter(Context context,int [] imgs,int width,int height ,int selected) {
		super();
		this.context = context;
		this.selected = selected;
		//开辟ImageView的空间
		this.imageViews = new ImageView[imgs.length];
		
		for(int i=0;i<imgs.length;i++){
			this.imageViews[i] = new ImageView(context);
			//设定显示风格
			this.imageViews[i].setLayoutParams(new GridView.LayoutParams(width,height));
			//设定调整边距显示
			this.imageViews[i].setAdjustViewBounds(false);
			//设定边距
			this.imageViews[i].setPadding(3, 3, 3, 3);
			//设定图片
			this.imageViews[i].setImageResource(imgs[i]);
		}
		
	}

	@Override
	public int getCount() {
		// TODO Auto-generated method stub
		return imageViews.length;
	}

	@Override
	public Object getItem(int position) {
		// TODO Auto-generated method stub
		return imageViews[position];
	}

	@Override
	public long getItemId(int position) {
		// TODO Auto-generated method stub
		return 0;
	}

	@Override
	public View getView(int position, View convertView, ViewGroup parent) {
		//图片显示
		//convertView 判断是否存在视图
		ImageView newImage = null;
		if(convertView == newImage){
			newImage = this.imageViews[position];
		}else{
			//当存在视图，直接转换为ImageView
			newImage = (ImageView) convertView;
		}
		return newImage;
	}
	
	//设定选中显示
	public void setFocus(int selectedID){
		//当没有背景的时候，设定为 0 为Null
		for(int i=0;i<imageViews.length;i++){
			if(i != selectedID){
				this.imageViews[i].setBackgroundResource(0);
			}
		}
		//设定选中的北京
		this.imageViews[selectedID].setBackgroundResource(R.drawable.menu_background);
	}
}