【Android进阶学习】shape和selector的结合使用（转）-阿里云开发者社区

原创作品，允许转载，转载时请务必以超链接形式标明文章原始出处、作者信息和本声明。否则将追究法律责任。 http://liangruijun.blog.51cto.com/3061169/732310

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">
<item android:drawable="@drawable/pic1" />
<item
android:state_window_focused="false"
android:drawable="@drawable/pic_blue"
/>
<item
android:state_focused="true"
android:state_pressed="true"
android:drawable= "@drawable/pic_red"
/>
<item
android:state_focused="false"
android:state_pressed="true"
android:drawable="@drawable/pic_pink"
/>
<item
android:state_selected="true"
android:drawable="@drawable/pic_orange"
/>
<item
android:state_focused="true"
android:drawable="@drawable/pic_green"
/>
</selector>

第一个例子：圆角的Button

http://liangruijun.blog.51cto.com/3061169/630051

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

先看看这个例子的结构：

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;
}
}