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Android适配器Adapter学习

2013年09月06日 ⁄ 综合 ⁄ 共 6967字 ⁄ 字号 评论关闭

转自:http://www.2cto.com/kf/201112/113035.html

在开发中我们需要绑定一些数据展现到桌面上,这是就需要AdapterView。AdapterView是ViewGroup的子类,它决定了怎么展现视图通过Adapter来绑定特殊的数据类型。AdapterView是非常有帮助的当你展现数据在你的布局中。Gallery,ListView和Spinner是AdapterView的子类。

 

      下面看一下AdapterView的结构图:

      \     

 

 

      然后再看一下Adapter的结构图:

 

    \

 

    上面已经充分展现了他们的子类和父类的基础关系。

 

     下面我们看一个ListViewDemo的例子:

 

    先来看一个简单的adapter的例子:

 

  

 

 

public class SimpleList extends ListActivity { 

    private String[] mListString={"姓名:王魁锋","性别:男","年龄:23", 

            "居住地:上海市普陀区","邮箱:wangkuifeng0118@126.com"}; 

    private ListView mListView=null; 

    @Override 

    protected void onCreate(Bundle savedInstanceState) { 

        // TODO Auto-generated method stub 

        super.onCreate(savedInstanceState); 

        mListView=this.getListView(); 

        setListAdapter(new ArrayAdapter<String>(this, 

            android.R.layout.simple_list_item_1,mListString)); 

        mListView.setOnItemClickListener(new OnItemClickListener() { 

 

            @Override 

            public void onItemClick(AdapterView<?> parent, View view, 

                    int position, long id) { 

                // TODO Auto-generated method stub 

            Toast.makeText(SimpleList.this, "你选择了:"+mListString[position], 1).show(); 

            } 

        }); 

    } 

 

  这里用到了系统定义好的适配模式,当然这只能用来简单的数据适配,下面看一下效果:

     \

 

    接下来看一个稍微复杂点的,SimpleAdapter怎么适配:

 

  

 

 

public class IconList extends ListActivity { 

 

     private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};   

        private String[] mListStr = { "王魁锋", "男", "23", "上海市普陀区",   

            "wangkuifeng0118@126.com"};   

        ListView mListView = null;   

        ArrayList<Map<String,Object>> mData= new ArrayList<Map<String,Object>>();;   

       

        @Override 

        protected void onCreate(Bundle savedInstanceState) { 

            // TODO Auto-generated method stub 

             mListView = getListView();   

                 

            int lengh = mListTitle.length;   

            for(int i =0; i < lengh; i++) {   

                Map<String,Object> item = new HashMap<String,Object>();   

                item.put("image", R.drawable.portrait);   

                item.put("title", mListTitle[i]);   

                item.put("text", mListStr[i]);   

                mData.add(item);    

            }   

            SimpleAdapter adapter = new SimpleAdapter(this,mData,R.layout.iconlist,   

                new String[]{"image","title","text"},new int[]{R.id.image,R.id.title,R.id.text});    

                setListAdapter(adapter);   

            mListView.setOnItemClickListener(new OnItemClickListener() {   

                @Override 

                public void onItemClick(AdapterView<?> parent, View view, 

                        int position, long id) { 

                    // TODO Auto-generated method stub 

                     Toast.makeText(IconList.this,"您选择了标题:" + mListTitle[position] + "    内容:"+mListStr[position], Toast.LENGTH_LONG).show();   

                      

                }   

            });   

            super.onCreate(savedInstanceState); 

        } 

    上面的数据可以是同数据库读取的也可以是从网络获取的,这里不做过多介绍,看下效果:

   \

 

      哈哈 看起来美观了些,如果要做更复杂的布局,哪就要用BaseAdapter了。先看一下布局文件:

 

 

 

<?xml version="1.0" encoding="utf-8"?>   

   

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"   

    android:layout_width="fill_parent" android:layout_height="wrap_content">   

    <ImageView android:id="@+id/color_image"   

        android:layout_width="wrap_content" android:layout_height="fill_parent"   

        android:layout_alignParentTop="true" android:layout_alignParentBottom="true"   

        android:adjustViewBounds="true"   

        android:padding="2dip" />   

    <TextView android:id="@+id/color_title"   

        android:layout_width="fill_parent" android:layout_height="wrap_content"   

        android:layout_toRightOf="@+id/color_image"   

        android:layout_alignParentTop="true"   

        android:layout_alignParentRight="true" android:singleLine="true"   

        android:ellipsize="marquee"    

        android:textSize="15dip"  />   

    <TextView android:id="@+id/color_text"   

        android:layout_width="fill_parent" android:layout_height="wrap_content"   

        android:layout_toRightOf="@+id/color_image"   

        android:layout_below="@+id/color_title"   

        android:layout_alignParentBottom="true"   

        android:layout_alignParentRight="true"    

        android:singleLine="true"   

        android:ellipsize="marquee"    

        android:textSize="20dip" />   

</RelativeLayout>   

  

下面是核心代码:

 

 

 

public class ColorList extends ListActivity { 

     private String[] mListTitle = { "姓名", "性别", "年龄", "居住地","邮箱"};   

     private String[] mListText={"王魁锋","男","23","上海市普陀区","wangkuifeng0118@126.com"}; 

     private ListView mListView=null; 

     private MyListAdapter myAdapter=null; 

    @Override 

    protected void onCreate(Bundle savedInstanceState) { 

        // TODO Auto-generated method stub 

         mListView=this.getListView(); 

         myAdapter=new MyListAdapter(this); 

         this.setListAdapter(myAdapter); 

          

         mListView.setOnItemClickListener(new OnItemClickListener() { 

 

            @Override 

            public void onItemClick(AdapterView<?> parent, View view, 

                    int position, long id) { 

                // TODO Auto-generated method stub 

                View v=parent.getChildAt(position); 

                v.setBackgroundColor(Color.RED); 

                Toast.makeText(ColorList.this, "你选择了"+mListText[position], 1).show(); 

            } 

        }); 

        super.onCreate(savedInstanceState); 

    } 

    private class MyListAdapter extends BaseAdapter{ 

        private Context mContext; 

        private int[] colors=new int[]{0xff626569,0xff4f5257 }; 

         public MyListAdapter(Context context){ 

             mContext=context; 

         } 

        @Override 

        public int getCount() { 

            // TODO Auto-generated method stub 

            return mListText.length; 

        } 

 

        @Override 

        public Object getItem(int position) { 

            // TODO Auto-generated method stub 

            return position; 

        } 

 

        @Override 

        public long getItemId(int position) { 

            // TODO Auto-generated method stub 

            return position; 

        } 

 

        @Override 

        public View getView(int position, View convertView, ViewGroup parent) { 

            ImageView image=null; 

            TextView title=null; 

            TextView  content=null; 

            if(convertView==null){ 

                convertView=LayoutInflater.from(mContext).inflate(R.layout.colorlist, null); 

                image=(ImageView) convertView.findViewById(R.id.color_image); 

                title=(TextView) convertView.findViewById(R.id.color_title); 

                content=(TextView) convertView.findViewById(R.id.color_text); 

            } 

            int colorPos=position%colors.length; 

            convertView.setBackgroundColor(colors[colorPos]); 

            title.setText(mListTitle[position]); 

            content.setText(mListText[position]); 

            image.setImageResource(R.drawable.portrait); 

             

            return convertView; 

        } 

         

    } 

 

     BaseAdapter可以让我们做比较复杂的布局,只要在xml文件中设置好布局格式,在getView中分别取出放入相应的值就可以了。下面看一些效果:

  \

 

    还有一些SpinnerAdapter和SimpleCursorAdapter等系统自带的适配器,都是比较简单的,可以看下API自行练习一下,这里特别说明一下,从数据库里取出的数据最好直接放入SimpleCursorAdapter很方便的

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