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: