android自定义View---生成虚线的View

1.在res/values/目录下 新建文件 attrs.xml

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

<  resources >

 

     < declare-styleable  name  =  "dashedline" >

         < attr  name  =  "lineColor"   format =  "color"   />

     </ declare-styleable  >

 

</  resources >

 

2.创建自定义View，DashedLine.java

public  class  DashedLine  extends  View {

            private  Paint  paint  =  null ;

            private  Path  path  =  null ;

            private  PathEffect  pe  =  null ;

 

            public  DashedLine(Context paramContext) {

                     this (paramContext,  null );

          }

 

            public  DashedLine(Context paramContext, AttributeSet paramAttributeSet) {

                     super (paramContext, paramAttributeSet);

                       //通过R.styleable.dashedline获得我们在attrs.xml中定义的

//<declare- styleable  name=" dashedline ">  TypedArray

                   TypedArray a = paramContext.obtainStyledAttributes(paramAttributeSet, R.styleable.  dashedline );

                     //我们在attrs.xml中<declare- styleable  name=" dashedline ">节点下

//添加了<attr name="lineColor" format="color" />

                     //表示这个属性名为lineColor类型为color。当用户在布局文件中对它有设定值时

                     //可通过TypedArray获得它的值当用户无设置值是采用默认值0XFF00000

                     int  lineColor = a.getColor(R.styleable.  dashedline_lineColor , 0XFF000000);

                   a.recycle();

                     this .  paint  =  new  Paint();

                     this .  path  =  new  Path();

                     this .  paint .setStyle(Paint.Style.  STROKE );

                     this .  paint .setColor(lineColor);

                     this .  paint .setAntiAlias(  true );

                     this .  paint .setStrokeWidth(BitmapHelper.  dip2px (getContext(), 2.0F));

                     float [] arrayOfFloat =  new   float [4];

                   arrayOfFloat[0] = BitmapHelper.  dip2px (getContext(), 2.0F);

                   arrayOfFloat[1] = BitmapHelper.  dip2px (getContext(), 2.0F);

                   arrayOfFloat[2] = BitmapHelper.  dip2px (getContext(), 2.0F);

                   arrayOfFloat[3] = BitmapHelper.  dip2px (getContext(), 2.0F);

                     this .  pe  =  new  DashPathEffect(arrayOfFloat, BitmapHelper. dip2px (getContext(), 1.0F));

          }

 

            @Override

            protected   void  onDraw(Canvas canvas) {

                     super .onDraw(canvas);

                     this .  path .moveTo(0.0F, 0.0F);

                     this .  path .lineTo(getMeasuredWidth(), 0.0F);

                     this .  paint .setPathEffect(  this .  pe );

                   canvas.drawPath(  this .  path ,  this .  paint );

          }

 

}

3.新建布局文件dashedline.xml

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

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

     xmlns:dash =  "http://schemas.android.com/apk/res/com.example.martixtest"

     android:layout_width =  "fill_parent"

     android:layout_height =  "fill_parent"

     android:background =  "#eee"

     android:orientation =  "vertical"   >

 

     < com.example.martixtest.myview.DashedLine

         android:layout_width =  "fill_parent"

         android:layout_height =  "1dip"

         android:layout_margin =  "10dip"

         dash:lineColor =  "#ff50f8"   />

 

     < com.example.martixtest.myview.DashedLine

         android:layout_width =  "fill_parent"

         android:layout_height =  "1dip"

         android:layout_margin =  "10dip" />

 

     < com.example.martixtest.myview.DashedLine

         android:layout_width =  "fill_parent"

         android:layout_height =  "1dip"

         android:layout_margin =  "10dip"

         dash:lineColor =  "#f34f71"   />

 

</  LinearLayout >

4.最终运行效果如下: