[转]Android开发教程：shape和selector的结合使用

shape和selector是Android UI设计中经常用到的，比如我们要自定义一个圆角Button，点击Button有些效果的变化，就要用到shape和selector。可以这样说，shape和selector在美化控件中的作用是至关重要的。

1.Shape

简介

作用：XML中定义的几何形状

位置：res/drawable/文件的名称.xml

使用的方法：

Java代码中：R.drawable.文件的名称

XML中：Android:background="@drawable/文件的名称"

属性：

<shape>  Android:shape=["rectangle" | "oval" | "line" | "ring"]

其中rectagle矩形，oval椭圆，line水平直线，ring环形

<shape>中子节点的常用属性：

<gradient>  渐变

Android:startColor  起始颜色

Android:endColor  结束颜色             

Android:angle  渐变角度，0从上到下，90表示从左到右，数值为45的整数倍默认为0；

Android:type  渐变的样式 liner线性渐变 radial环形渐变 sweep

<solid >  填充

Android:color  填充的颜色

<stroke > 描边

Android:width 描边的宽度

Android:color 描边的颜色

Android:dashWidth 表示'-'横线的宽度

Android:dashGap 表示'-'横线之间的距离

<corners > 圆角

Android:radius  圆角的半径 值越大角越圆

Android:topRightRadius  右上圆角半径

Android:bottomLeftRadius 右下圆角角半径

Android:topLeftRadius 左上圆角半径

Android:bottomRightRadius 左下圆角半径

2.Selector

简介

位置：res/drawable/文件的名称.xml

使用的方法：

Java代码中：R.drawable.文件的名称

XML中：Android:background="@drawable/文件的名称"

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

<selector xmlns:Android="http://schemas.android.com/apk/res/android">   

<!-- 默认时的背景图片-->    

<item Android:drawable="@drawable/pic1" />      

<!-- 没有焦点时的背景图片 -->    

<item 

   Android:state_window_focused="false"      

   android:drawable="@drawable/pic_blue" 

   />     

<!-- 非触摸模式下获得焦点并单击时的背景图片 -->    

<item 

   Android:state_focused="true" 

   android:state_pressed="true"   

   android:drawable= "@drawable/pic_red" 

   />   

<!-- 触摸模式下单击时的背景图片-->    

<item 

   Android:state_focused="false" 

   Android:state_pressed="true"   

   Android:drawable="@drawable/pic_pink" 

   />    

<!--选中时的图片背景-->    

<item 

   Android:state_selected="true" 

   android:drawable="@drawable/pic_orange" 

   />     

<!--获得焦点时的图片背景-->    

<item 

   Android:state_focused="true" 

   Android:drawable="@drawable/pic_green" 

   />     

</selector> 

第一个例子：圆角的Button

第二个例子：shape+selector综合使用的例子 漂亮的ListView

selector.xml

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

<selector xmlns:Android="http://schemas.android.com/apk/res/android"> 

    <item Android:state_selected="true"> 

        <shape> 

            <gradient Android:angle="270" android:endColor="#99BD4C" 

                android:startColor="#A5D245" /> 

            <size Android:height="60dp" android:width="320dp" /> 

            <corners android:radius="8dp" /> 

        </shape> 

    </item> 

    <item Android:state_pressed="true"> 

        <shape> 

            <gradient Android:angle="270" android:endColor="#99BD4C" 

                android:startColor="#A5D245"/> 

            <size Android:height="60dp" android:width="320dp" /> 

            <corners android:radius="8dp" /> 

        </shape> 

    </item> 

    <item> 

        <shape> 

            <gradient Android:angle="270" android:endColor="#A8C3B0" 

                android:startColor="#C6CFCE"  /> 

            <size Android:height="60dp" android:width="320dp" /> 

            <corners android:radius="8dp" /> 

        </shape> 

    </item> 

</selector> 

list_item.xml

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

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

    android:orientation="horizontal"   

    Android:layout_width="fill_parent"    

    android:layout_height="wrap_content" 

    Android:background="@drawable/selector" 

    >                     

    <ImageView   

        Android:id="@+id/img"    

        Android:layout_width="wrap_content"   

        android:layout_height="wrap_content"              

        Android:layout_gravity="center_vertical" 

        android:layout_marginLeft="20dp"          

        />                            

        <TextView   

            Android:text="data"   

            android:id="@+id/title" 

            Android:layout_width="fill_parent"   

            android:layout_height="wrap_content"   

            Android:gravity="center_vertical"    

            android:layout_marginLeft="20dp"   

            Android:layout_marginTop="20dp"   

            android:textSize="14sp"                           

            Android:textStyle="bold" 

            android:textColor="@color/black"                          

            > 

        </TextView>           

 </LinearLayout> 

main.xml

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

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

        android:orientation="vertical"   

        Android:layout_width="fill_parent"    

        android:layout_height="wrap_content" 

        Android:background="#253853" 

        >                                 

        <ListView   

          Android:id="@+id/list"   

          Android:layout_width="match_parent"   

          android:layout_height="match_parent" 

          Android:cacheColorHint="#00000000" 

          android:divider="#2A4562" 

          Android:dividerHeight="3px" 

          android:listSelector="#264365" 

          Android:drawSelectorOnTop="false"  

          > 

        </ListView>   

</LinearLayout> 

colors.xml

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

<resources> 

    <color name="white">#FFFFFFFF</color> 

    <color name="transparency">#00000000</color> 

    <color name="title_bg">#1C86EE</color> 

    <color name="end_color">#A0cfef83</color> 

    <color name="black">#464646</color> 

</resources> 

MainActivity.xml

package com.lingdududu.customlist;  
import java.util.ArrayList;  
import java.util.HashMap;  
import xb.customlist.R;  
import Android.R.array;  
import android.app.Activity;  
import Android.os.Bundle;  
import android.widget.ArrayAdapter;  
import Android.widget.ListView;  
import android.widget.SimpleAdapter;  
public class MainActivity extends Activity {  
    ListView list;  
    String data[] = new String[]{  
            "China","UK","USA","Japan","German","Canada","ET","Narotu"    
    };  
    /** Called when the activity is first created. */ 
    @Override 
    public void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.main);  
        list =(ListView) findViewById(R.id.list);          
        SimpleAdapter adapter = new SimpleAdapter(this, getData(), R.layout.list_item,   
                new String[]{"title","img"}, new int[]{R.id.title,R.id.img});  
        list.setAdapter(adapter);          
    }  
    private ArrayList<HashMap<String, Object>> getData() {        
        ArrayList<HashMap<String, Object>> dlist = new ArrayList<HashMap<String,Object>>();  
        for(int i =0;i<data.length;i++){  
            HashMap<String, Object>map = new HashMap<String, Object>();           
            map.put("title", data[i]);  
            map.put("img", R.drawable.item_left2);  
            dlist.add(map);   
        }  
        return dlist;  
    }  
}

转自：http://www.cnblogs.com/top5/archive/2012/05/10/2494763.html