<!-- drawable 文件 -->
<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
 android:shape="line">
 <stroke
 android:width="1dp"
 android:color="@color/dash_line"
 android:dashGap="2dp"
 android:dashWidth="3dp"/>
</shape>

<!-- 布局文件 -->
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
 xmlns:android="http://schemas.android.com/apk/res/android"
 xmlns:tools="http://schemas.android.com/tools"
 android:id="@+id/activity_main"
 android:layout_width="match_parent"
 android:layout_height="wrap_content"
 android:orientation="vertical"
 android:gravity="center"
 tools:context="hope.example.dashlinedemo.MainActivity">

 <TextView
 android:layout_width="match_parent"
 android:layout_height="40dp"
 android:gravity="center"
 android:text="分享给微信好友"/>

 <View
 android:layout_width="match_parent"
 android:layout_height="2dp"
 android:background="@drawable/dash_line" />

 <TextView
 android:layout_width="match_parent"
 android:layout_height="40dp"
 android:gravity="center"
 android:text="分享至朋友圈" />
</LinearLayout>

<View
 android:layout_width="match_parent"
 android:layout_height="2dp"
 android:background="@drawable/dash_line"
 android:layerType="software"/>

public class DashLineView extends View {

 private Paint mPaint;

 public DashLineView(Context context, AttributeSet attrs) {
 super(context, attrs);

 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
 mPaint.setColor(getResources().getColor(R.color.dash_line));
 mPaint.setStrokeWidth(3);
 mPaint.setPathEffect(new DashPathEffect(new float[] {5, 5}, 0));

 }

 @Override
 protected void onDraw(Canvas canvas) {
 int centerY = getHeight() / 2;
 canvas.drawLine(0, centerY, getWidth(), centerY, mPaint);
 }
}

@Override
protected void onDraw(Canvas canvas) {
 int centerY = getHeight() / 2;
 setLayerType(LAYER_TYPE_SOFTWARE, null);
 canvas.drawLine(0, centerY, getWidth(), centerY, mPaint);
}

public class DashLineView extends View {

 private Paint mPaint;
 private Path mPath;

 public DashLineView(Context context, AttributeSet attrs) {
 super(context, attrs);

 mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
 mPaint.setColor(getResources().getColor(R.color.dash_line));
 // 需要加上这句，否则画不出东西
 mPaint.setStyle(Paint.Style.STROKE);
 mPaint.setStrokeWidth(3);
 mPaint.setPathEffect(new DashPathEffect(new float[] {15, 5}, 0));

 mPath = new Path();
 }

 @Override
 protected void onDraw(Canvas canvas) {
 int centerY = getHeight() / 2;
 mPath.reset();
 mPath.moveTo(0, centerY);
 mPath.lineTo(getWidth(), centerY);
 canvas.drawPath(mPath, mPaint);
 }
}

Path path = new Path();
path.addCircle(0, 0, 3, Path.Direction.CW);
mPaint.setPathEffect(new PathDashPathEffect(path, 15, 0, PathDashPathEffect.Style.ROTATE));

// 其它方法还是不变
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
 super.onSizeChanged(w, h, oldw, oldh);

 // 前四个参数没啥好讲的，就是起点和终点而已。
 // color数组的意思是从透明 -> 黑 -> 黑 -> 透明。
 // float数组与color数组对应：
 // 0 -> 0.3 (透明 -> 黑)
 // 0.3 - 0.7 (黑 -> 黑，即不变色)
 // 0.7 -> 1 (黑 -> 透明)
 mPaint.setShader(new LinearGradient(0, 0, getWidth(), 0,
  new int[] {Color.TRANSPARENT, Color.BLACK, Color.BLACK, Color.TRANSPARENT},
  new float[] {0, 0.3f, 0.7f, 1f}, Shader.TileMode.CLAMP));
}