1. 程式人生 > >listview巢狀gridview,並實現grid元素部分顯示以及點選展開與摺疊

listview巢狀gridview,並實現grid元素部分顯示以及點選展開與摺疊

有時我們需要用GridView顯示目錄列表,有時甚至是二級的,即listview每一個item裡面又各自嵌入一個gridview,但是當二級目錄(資料條目)的數量過多時,介面會比較臃腫,這時我們就想要有類似展開與摺疊的效果,作者採用的策略是資料分段的分別顯示,其中對於顯示邊界(處於限制顯示數目的特定位置)的控制元件要有資料的動態更新和點選判斷操作。效果如圖:

哈哈

具體實現:

一、Activity介面

package com.example.gridinlist;

import java.util.Vector;

import android.app.Activity;
import android.os.Bundle;
import android.widget.ListView;

public class MainActivity extends Activity {

	private ListView listView;
	private MyAdapter adapter;
	private Vector<String> stringVector = new Vector<String>();
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initView();
	}

	private void initView() {
		listView = (ListView) findViewById(R.id.list);
		adapter = new MyAdapter(this, this.getLayoutInflater(), stringVector);
		
		stringVector.add("0");
		stringVector.add("1");
		stringVector.add("2");
		stringVector.add("3");
		stringVector.add("4");
		stringVector.add("5");
		
		listView.setAdapter(adapter);
	}
}
    主Activity,裡面只有一個textview(標題)和listview(主體),其中Listview的介面卡MyAdapter是自寫的(也是實現效果的主要邏輯程式碼)。

    這裡我們直傳給MyAdapter一個字串向量,為了簡便,不管一級還是二級目錄都是用的這一個向量(實際中每個二級子向量應該都是不同的),使用者可根據需求自行新增或修改(也可以使用Parcel將其封裝為一個二級的資料型別,具體不再贅述)。

Activity佈局檔案

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="${relativePackage}.${activityClass}" >

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:gravity="center_horizontal"
        android:layout_centerHorizontal="true"
        android:text="@string/hello_world" />
    
    <ListView 
    	 android:id="@+id/list"
		 android:layout_width="fill_parent"
		 android:layout_height="fill_parent"
		 android:layout_marginLeft="7dip"
       	 android:layout_marginRight="7dip"
       	 android:layout_marginBottom="7dip"
       	 android:layout_below="@+id/title"
		 android:cacheColorHint="#00000000"
		 android:drawSelectorOnTop="false" 
		 android:listSelector="#00000000"
		 android:scrollbars="none"
		 android:scrollingCache="true"
    	 android:drawingCacheQuality="low"
    	 android:divider="#00000000"
    	 android:dividerHeight="0dip"
    	 android:fadingEdgeLength="0.0sp" 
   	/>
    

</RelativeLayout>

二、自寫的istview的Adapter(關鍵程式碼)
package com.example.gridinlist;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.Vector;
import android.annotation.SuppressLint;
import android.content.Context;
import android.database.DataSetObserver;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.BaseAdapter;
import android.widget.GridView;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

public class MyAdapter extends BaseAdapter
{
	private static final String TAG = "MyAdapter";
	private LayoutInflater inflater;
	private Context context;
	private Vector<String> vector;
	private int numGridShowLimit = 4; //Gridview限定顯示數目
	
	/**
	 * 搜尋Adapter初始化
	 */
	public MyAdapter(Context context,LayoutInflater inflater,Vector<String> vector) 
	{
		this.context = context;
		this.inflater = inflater;
		this.vector = vector;
	}

	/**
	 * 初始化View
	 */
	private static class ViewHolder
	{
		private TextView  titleTextView;
		private GridView  contentGridView;
		private GridView  contentMoreGridView;
	}
	
	/**
	 * 新增資料
	 */
	@SuppressLint("InflateParams")
	@Override
	public View getView(int position, View convertView, ViewGroup parent) 
	{
		final ViewHolder viewHolder;
		if( convertView == null )
		{
			convertView = inflater.inflate(R.layout.adapter_listview,null);
			viewHolder = new ViewHolder();
			viewHolder.titleTextView  = (TextView) convertView.findViewById(R.id.list_txt_title);
			viewHolder.contentGridView = (GridView) convertView.findViewById(R.id.list_grid);
			viewHolder.contentMoreGridView = (GridView) convertView.findViewById(R.id.list_grid_more);
			convertView.setTag(viewHolder);
		}
		else viewHolder = (ViewHolder) convertView.getTag();
		
		try 
		{
			if(vector != null && vector.size() > 0)
			{
				final String category = vector.get(position);
				if(category != null)
				{
					viewHolder.titleTextView.setText("list item "+category);
				}
				
				if (vector.size() > 0) {
					final ArrayList<HashMap<String, Object>> categoryList = new ArrayList<HashMap<String, Object>>();
					final ArrayList<HashMap<String, Object>> categorySubList1 = new ArrayList<HashMap<String, Object>>();
					final ArrayList<HashMap<String, Object>> categorySubList2 = new ArrayList<HashMap<String, Object>>();
					//先封裝整個資料向量到categoryList
					if (vector != null && vector.size() > 0) {
						for (int i = 0; i < vector.size(); i++) {
							String o = vector.get(i);
							if (o != null) {
								HashMap<String, Object> map = new HashMap<String, Object>();
								map.put("ItemText", "grid" + o);
								categoryList.add(map);
							}
						}
					}
					final int mypos = position;
					
					//當資料向量長度大於限定顯示的grid數目時,將整個資料向量分成兩段
					if (vector.size() > numGridShowLimit) {
						
						//封裝前段資料到categorySubList1
						for (int i = 0; i < numGridShowLimit; i++) {
							String o = vector.get(i);
							if (o != null) {
								if (i==numGridShowLimit-1) {
									HashMap<String, Object> map = new HashMap<String, Object>();
									if (viewHolder.contentMoreGridView.getVisibility()==View.GONE) {
										//若處於摺疊狀態則將限定數目的位置的資料修改為“+”(用於點選展開)
										map.put("ItemText", "" + "+");
									}else {
										//若處於展開狀態則限定數目的位置的資料正常顯示
										map.put("ItemText", "grid" + o);
									}
									categorySubList1.add(map);
								}else {
									HashMap<String, Object> map = new HashMap<String, Object>();
									map.put("ItemText", "grid" + o);
									categorySubList1.add(map);
								}
								
							}
						}
						
						//封裝後段資料到categorySubList2
						for (int i = numGridShowLimit; i < vector.size(); i++) {
							String o = vector.get(i);
							if (o != null) {
								HashMap<String, Object> map = new HashMap<String, Object>();
								map.put("ItemText", "grid" + o);
								categorySubList2.add(map);
							}
						}
						HashMap<String, Object> map = new HashMap<String, Object>();
						map.put("ItemText", "-"); //在第二段的最後新增一個“-”資料(用於點選摺疊)
						categorySubList2.add(map);
						
						//建立第一部分GridView的adapter
						final SimpleAdapter simpleAdapter1 = new SimpleAdapter(context, categorySubList1,
								R.layout.adapter_gridview,
								new String[] { "ItemText" }, // 對應map的Key
								new int[] { R.id.ItemText }); // 對應R的Id
						viewHolder.contentGridView.setAdapter(simpleAdapter1);
						
						//建立第二部分GridView的adapter
						final SimpleAdapter simpleAdapter2 = new SimpleAdapter(context, categorySubList2,
								R.layout.adapter_gridview,
								new String[] { "ItemText" }, // 對應map的Key
								new int[] { R.id.ItemText }); // 對應R的Id
						viewHolder.contentMoreGridView.setAdapter(simpleAdapter2);
						
						//設定第二部分GridView的adapter中的具體item點選事件
						viewHolder.contentMoreGridView.setOnItemClickListener(new OnItemClickListener() {
							public void onItemClick(AdapterView<?> AdapterView, View view,int pos, long row) {
								if (categoryList.size()>numGridShowLimit && pos==categoryList.size()-numGridShowLimit) {
									//若點選末尾的“-”,則將gridview摺疊,並修改第一部分最後位置為“+”(可展開狀態)
									View rel =  (View) viewHolder.contentGridView.getChildAt(numGridShowLimit-1);
									TextView tv =  (TextView) rel.findViewById(R.id.ItemText);
									tv.setText("+");
									viewHolder.contentMoreGridView.setVisibility(View.GONE);
								}else {
									view.setTag(mypos*100+numGridShowLimit+pos);
									Toast.makeText(context, " list position:"+ mypos+"\ngrid position:"+pos, Toast.LENGTH_SHORT).show();
								}
							}
						});
					}
					else {
						//若資料向量數目不大於限定的顯示數目,則正常建立第一部分GridView的adapter(直接使用整體資料categoryList)
						final SimpleAdapter simpleAdapter = new SimpleAdapter(context, categoryList,
								R.layout.adapter_gridview,
								new String[] { "ItemText" }, // 對應map的Key
								new int[] { R.id.ItemText }); // 對應R的Id
						viewHolder.contentGridView.setAdapter(simpleAdapter);
					}
					
					//設定第一部分GridView的adapter中的具體item點選事件
					viewHolder.contentGridView.setOnItemClickListener(new OnItemClickListener() {
						public void onItemClick(AdapterView<?> AdapterView, View view,int pos, long row) {
							if (categoryList.size()>numGridShowLimit && pos==numGridShowLimit-1) {
								TextView tv =  (TextView) view.findViewById(R.id.ItemText);
								String content = tv.getText().toString();
								if (content.equals("+")) {
									//若點選“+”,則進行展開操作,即顯示第二部分gridview,並修改最後位置為“+”
									tv.setText("grid"+vector.get(numGridShowLimit-1));
									viewHolder.contentMoreGridView.setVisibility(View.VISIBLE);
								}else {
									view.setTag(mypos*100+pos);
									Toast.makeText(context, " list position:"+ mypos+"\ngrid position:"+pos, Toast.LENGTH_SHORT).show();
								}
							}else {
								view.setTag(mypos*100+pos);
								Toast.makeText(context, " list position:"+ mypos+"\ngrid position:"+pos, Toast.LENGTH_SHORT).show();
							}
						}
					});
				}
			}
		} 
		catch (Exception e) 
		{
			e.printStackTrace();
			Log.e(TAG, "Exception");
		}
		
		return convertView;
	}
	
	@Override
	public int getCount() 
	{
	    return vector.size();
	}
	
	@Override
	public Object getItem(int position) {
		return null;
	}

	@Override
	public long getItemId(int position) {
		return 0;
	}
	
	@Override
	public void unregisterDataSetObserver(DataSetObserver observer) 
	{
		 if (observer != null) {
	         super.unregisterDataSetObserver(observer);
	     }
	}
}
    具體步驟請看程式碼中的註釋,需要注意的是,裡面的GridView使用的是自寫的控制元件,因為若使用Android自帶的GridView,會出現在ListView中只顯示一行grid的情況,這是因為ListView無法動態獲取GridView的數目而無法確定它的高度,因此預設認為只有一行資料。

解決方法是:在自寫的GridView裡面,需要重寫onMeasure方法,這樣就可以得到GridView的高度了,程式碼如下:

package com.example.gridinlist;

import android.widget.GridView;

public class MyGridView extends GridView  
{  
    public MyGridView(android.content.Context context,  
            android.util.AttributeSet attrs)  
    {  
        super(context, attrs);  
    }  

	/**
	 * 重寫的onMeasure方法
	 */
    public void onMeasure(int widthMeasureSpec, int heightMeasureSpec)  
    {  
        int expandSpec = MeasureSpec.makeMeasureSpec(Integer.MAX_VALUE >> 2,  
                MeasureSpec.AT_MOST);  
        super.onMeasure(widthMeasureSpec, expandSpec);  
  
    }  
  
}

ListView的item佈局檔案:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:layout_marginTop="1dip"
    android:layout_marginBottom="1dip"
    android:orientation="vertical"
    android:baselineAligned="false"
    android:background="#ffffff"
>

    <RelativeLayout 
    	android:id="@+id/list_rel"
    	android:layout_width="fill_parent"
    	android:layout_height="wrap_content"
    	android:layout_marginTop="10dip"
    	android:layout_marginBottom="10dip"
    >
    
        <ImageView
            android:id="@+id/list_img_icon"
            android:layout_width="3dip"
            android:layout_height="17dip"
            android:layout_marginLeft="15dip"
            android:contentDescription="@null"
            android:scaleType="fitXY"
            android:layout_centerVertical="true"
            android:src="@drawable/selected_orange"
            android:visibility="visible" />
    
        <TextView 
	    	android:id="@+id/list_txt_title"
	    	android:layout_width="wrap_content"
	    	android:layout_height="wrap_content"
	    	android:layout_toRightOf="@+id/list_img_icon"
	    	android:layout_marginLeft="7dip"
	    	android:layout_marginRight="7dip"
	    	android:gravity="center"
	    	android:layout_centerVertical="true"
	    	android:singleLine="true"
	    />
        
    </RelativeLayout>
    
    <com.example.gridinlist.MyGridView
        android:id="@+id/list_grid"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_marginBottom="1dip"
        android:columnWidth="70dip"
        android:horizontalSpacing="10dip"
        android:verticalSpacing="10dip"
        android:listSelector="@android:color/transparent"
        android:numColumns="4"
        android:paddingLeft="15dip"
        android:paddingRight="15dip"
        android:scrollbars="none"
        android:stretchMode="columnWidth"
        android:visibility="visible" >
    </com.example.gridinlist.MyGridView>
    
    <com.example.gridinlist.MyGridView
        android:id="@+id/list_grid_more"
        android:layout_width="fill_parent"
        android:layout_height="fill_parent"
        android:layout_marginTop="10dip"
        android:layout_marginBottom="1dip"
        android:columnWidth="70dip"
        android:horizontalSpacing="10dip"
        android:verticalSpacing="10dip"
        android:listSelector="@android:color/transparent"
        android:numColumns="4"
        android:paddingLeft="15dip"
        android:paddingRight="15dip"
        android:scrollbars="none"
        android:stretchMode="columnWidth"
        android:visibility="gone" >
    </com.example.gridinlist.MyGridView>
    
</LinearLayout>
裡面包含一個標題,以及兩個自寫的GridView(一個顯示前面部分,另一個顯示剩下的,點選展開與摺疊其實就是第二個GridView的顯示與隱藏

GridView的item佈局檔案:

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >
    
    <TextView 
        android:id="@+id/ItemText"
        android:layout_width="70dip"
        android:layout_height="32dip"
        android:background="@drawable/btn_txt_bg"
        android:text=""
        android:gravity="center"
        />

</RelativeLayout>
只是簡單的一個TextView,使用者想擴充套件或豐富可自行修改。

程式碼下載連線:http://download.csdn.net/detail/duguju/9233759