在项目中我们会经常遇到这种圆角效果,因为直角的看起来确实不那么雅观,可能大家会想到用图片实现,试想上中下要分别做三张图片,这样既会是自己的项目增大也会增加内存使用量,所以使用shape来实现不失为一种更好的实现方式。在这里先看一下shape的使用:
- <? xml version = "1.0" encoding = "utf-8" ?>
- < shape xmlns:android = "http://schemas.android.com/apk/res/android"
- android:shape = "rectangle"
- >
- <!--渐变-->
- < gradient
- android:startColor = "#B5E7B8"
- android:endColor = "#76D37B"
- android:angle = "270"
- />
- <!--描边-->
- <!-- < stroke android:width = "1dip"
- android:color = "@color/blue"
- /> -- >
- <!--实心-->
- <!-- < solid android:color = "#FFeaeaea"
- /> -- >
- <!--圆角-->
- < corners
- android:bottomRightRadius = "4dip"
- android:bottomLeftRadius = "4dip"
- android:topLeftRadius = "4dip"
- android:topRightRadius = "4dip"
- />
- </ shape >
solid:实心,就是填充的意思
android:color指定填充的颜色
gradient:渐变
android:startColor和android:endColor分别为起始和结束颜色,ndroid:angle是渐变角度,必须为45的整数倍。
另外渐变默认的模式为android:type="linear",即线性渐变,可以指定渐变为径向渐变,android:type="radial",径向渐变需要指定半径android:gradientRadius="50"。
stroke:描边
android:width="2dp" 描边的宽度,android:color 描边的颜色。
我们还可以把描边弄成虚线的形式,设置方式为:
android:dashWidth="5dp"
android:dashGap="3dp"
其中android:dashWidth表示'-'这样一个横线的宽度,android:dashGap表示之间隔开的距离。
corners:圆角
android:radius为角的弧度,值越大角越圆。
OK,下面开始自定义listview实现圆角的例子:
首先在drawable下定义只有一项的选择器app_list_corner_round.xml:
- <? xml version = "1.0" encoding = "utf-8" ?>
- < shape xmlns:android = "http://schemas.android.com/apk/res/android"
- android:shape = "rectangle"
- >
- <!--渐变-->
- < gradient
- android:startColor = "#B5E7B8"
- android:endColor = "#76D37B"
- android:angle = "270"
- />
- <!--描边-->
- <!-- < stroke android:width = "1dip"
- android:color = "@color/blue"
- /> -- >
- <!--实心-->
- <!-- < solid android:color = "#FFeaeaea"
- /> -- >
- <!--圆角-->
- < corners
- android:bottomRightRadius = "4dip"
- android:bottomLeftRadius = "4dip"
- android:topLeftRadius = "4dip"
- android:topRightRadius = "4dip"
- />
- </ shape >
- <? xml version = "1.0" encoding = "utf-8" ?>
- < shape xmlns:android = "http://schemas.android.com/apk/res/android"
- android:shape = "rectangle"
- >
- < gradient
- android:startColor = "#B5E7B8"
- android:endColor = "#76D37B"
- android:angle = "270"
- />
- <!-- < stroke android:width = "1dip"
- android:color = "@color/blue"
- /> -- >
- <!-- < solid android:color = "#FFeaeaea"
- /> -- >
- < corners
- android:topLeftRadius = "4dip"
- android:topRightRadius = "4dip"
- />
- </ shape >
如果是底部最后一项,则下面两个角为圆角,app_list_corner_round_bottom.xml:
- <? xml version = "1.0" encoding = "utf-8" ?>
- < shape xmlns:android = "http://schemas.android.com/apk/res/android"
- android:shape = "rectangle"
- >
- < gradient
- android:startColor = "#B5E7B8"
- android:endColor = "#76D37B"
- android:angle = "270"
- />
- <!-- < stroke android:width = "1dip"
- android:color = "@color/blue"
- /> -- >
- <!-- < solid android:color = "#FFeaeaea"
- /> -- >
- < corners
- android:bottomRightRadius = "4dip"
- android:bottomLeftRadius = "4dip"
- />
- </ shape >
如果是中间项,则应该不需要圆角, app_list_corner_round_center.xml:
- <? xml version = "1.0" encoding = "utf-8" ?>
- < shape xmlns:android = "http://schemas.android.com/apk/res/android"
- android:shape = "rectangle"
- >
- < gradient
- android:startColor = "#B5E7B8"
- android:endColor = "#76D37B"
- android:angle = "270"
- />
- <!-- < stroke android:width = "1dip"
- android:color = "@color/blue"
- /> -- >
- <!-- < solid android:color = "#FFeaeaea"
- /> -- >
- <!-- < corners
- android:bottomRightRadius = "4dip"
- android:bottomLeftRadius = "4dip"
- /> -- >
- </ shape >
listview的背景图片大家可以使用stroke描述,这里我使用了一张9PNG的图片,因为9PNG图片拉伸不失真。
定义好了圆角的shape接下来是自定义listview的实现:
- packagecn.com.karl.view;
- importcn.com.karl.test.R;
- importandroid.content.Context;
- importandroid.util.AttributeSet;
- importandroid.view.MotionEvent;
- importandroid.widget.AdapterView;
- importandroid.widget.ListView;
- /**
- *圆角ListView
- */
- publicclassCornerListViewextendsListView{
- publicCornerListView(Contextcontext){
- super(context);
- }
- publicCornerListView(Contextcontext,AttributeSetattrs,intdefStyle){
- super(context,attrs,defStyle);
- }
- publicCornerListView(Contextcontext,AttributeSetattrs){
- super(context,attrs);
- }
- @Override
- publicbooleanonInterceptTouchEvent(MotionEventev){
- switch(ev.getAction()){
- caseMotionEvent.ACTION_DOWN:
- int x =(int)ev.getX();
- int y =(int)ev.getY();
- int itemnum = pointToPosition (x,y);
- if( itemnum ==AdapterView.INVALID_POSITION)
- break;
- else{
- if( itemnum ==0){
- if( itemnum ==(getAdapter().getCount()-1)){
- //只有一项
- setSelector(R.drawable.app_list_corner_round);
- }else{
- //第一项
- setSelector(R.drawable.app_list_corner_round_top);
- }
- }elseif( itemnum ==(getAdapter().getCount()-1))
- //最后一项
- setSelector(R.drawable.app_list_corner_round_bottom);
- else{
- //中间项
- setSelector(R.drawable.app_list_corner_round_center);
- }
- }
- break;
- caseMotionEvent.ACTION_UP:
- break;
- }
- returnsuper.onInterceptTouchEvent(ev);
- }
- }
下面看一下列表布局文件setting。xml:
- <? 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 = "fill_parent"
- android:orientation = "vertical" >
- < include layout = "@layout/head" />
- < cn.com.karl.view.CornerListView
- android:id = "@+id/setting_list"
- android:layout_width = "fill_parent"
- android:layout_height = "wrap_content"
- android:layout_margin = "10dip"
- android:background = "@drawable/corner_list_bg"
- android:cacheColorHint = "#00000000" />
- </ LinearLayout >
自定义Listview对应的item文件 main_tab_setting_list_item.xml
- <? 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" >
- < RelativeLayout
- android:layout_width = "fill_parent"
- android:layout_height = "50dp"
- android:gravity = "center_horizontal" >
- < TextView
- android:id = "@+id/tv_system_title"
- android:layout_width = "wrap_content"
- android:layout_height = "wrap_content"
- android:layout_alignParentLeft = "true"
- android:layout_centerVertical = "true"
- android:layout_marginLeft = "10dp"
- android:text = "分享"
- android:textColor = "@color/black" />
- < ImageView
- android:id = "@+id/iv_system_right"
- android:layout_width = "wrap_content"
- android:layout_height = "wrap_content"
- android:layout_alignParentRight = "true"
- android:layout_centerVertical = "true"
- android:layout_marginRight = "10dp"
- android:src = "@drawable/arrow1" />
- </ RelativeLayout >
- </ LinearLayout >
最后是在activity中填充适配器:
- packagecn.com.karl.test;
- importjava.util.ArrayList;
- importjava.util.HashMap;
- importjava.util.List;
- importjava.util.Map;
- importcn.com.karl.view.CornerListView;
- importandroid.os.Bundle;
- importandroid.view.View;
- importandroid.widget.SimpleAdapter;
- publicclassSettingActivityextendsBaseActivity{
- privateCornerListView cornerListView = null ;
- privateList < Map < String ,String > > listData = null ;
- privateSimpleAdapter adapter = null ;
- @Override
- protectedvoidonCreate(BundlesavedInstanceState){
- //TODOAuto-generatedmethodstub
- super.onCreate(savedInstanceState);
- setContentView(R.layout.setting);
- cornerListView =(CornerListView)findViewById(R.id.setting_list);
- setListData();
- adapter = new SimpleAdapter(getApplicationContext(),listData,R.layout.main_tab_setting_list_item,
- newString[]{"text"},newint[]{R.id.tv_system_title});
- cornerListView.setAdapter(adapter);
- initHead();
- btn_leftTop.setVisibility(View.INVISIBLE);
- tv_head.setText("设置");
- }
- /**
- *设置列表数据
- */
- privatevoidsetListData(){
- listData = new ArrayList < Map < String ,String > > ();
- Map < String ,String > map = new HashMap < String ,String > ();
- map.put("text","分享");
- listData.add(map);
- map = new HashMap < String ,String > ();
- map.put("text","检查新版本");
- listData.add(map);
- map = new HashMap < String ,String > ();
- map.put("text","反馈意见");
- listData.add(map);
- map = new HashMap < String ,String > ();
- map.put("text","关于我们");
- listData.add(map);
- map = new HashMap < String ,String > ();
- map.put("text","支持我们,请点击这里的广告");
- listData.add(map);
- }
- }
这样就完成了,虽然过程较繁杂,但是当做一个好的模板以后使用会方便很多,最后看一下实现效果和我们用图片实现的一样吗