How do I make a dotted/dashed line in Android?

Question

Without java code:

drawable/dotted.xml:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
android:shape="line">

    <stroke
       android:color="#FF00FF"
       android:dashWidth="10px"
       android:dashGap="10px"
       android:width="1dp"/>
</shape>

view.xml:

<ImageView
    android:layout_width="match_parent"
    android:layout_height="5dp"
    android:src="@drawable/dotted"
    android:layerType="software" />

Effect:

the path effect is set on the paint object

Paint fgPaintSel = new Paint();
fgPaintSel.setARGB(255, 0, 0,0);
fgPaintSel.setStyle(Style.STROKE);
fgPaintSel.setPathEffect(new DashPathEffect(new float[] {10f,20f}, 0f));

you can create all sorts of dotted patterns by supplying more numbers in the int[] array it specifies the ratios of dash and gap. This is a simple, equally dashed, line.

Creating dotted line using XML.
Create xml in drawable folder and give that background to the item to which you want to set dotted border.

Creating XML Background "dashed_border":

<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
    <item>
        <shape>
            <solid android:color="#ffffff" />
            <stroke
                android:dashGap="5dp"
                android:dashWidth="5dp"
                android:width="1dp"
                android:color="#0000FF" />
            <padding
                android:bottom="5dp"
                android:left="5dp"
                android:right="5dp"
                android:top="5dp" />
        </shape>
    </item>
</layer-list>

Adding that background to item:

<Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/dashed_border"/>

Create xml (view_line_dotted.xml):

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
        <item
            android:bottom="-1dp"
            android:left="-1dp"
            android:right="-1dp"
            android:top="0dp">

            <shape android:shape="rectangle">
                <stroke
                    android:width="1dp"
                    android:color="#ffff0017"
                    android:dashGap="3dp"
                    android:dashWidth="1dp" />

                <solid android:color="@android:color/transparent" />

                <padding
                    android:bottom="10dp"
                    android:left="10dp"
                    android:right="10dp"
                    android:top="10dp" />
            </shape>
        </item>
</layer-list>

Set as background of your view:

<View
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="@drawable/view_line_dotted" />

What I did when I wanted to draw a dotted line is to define a drawable dash_line.xml:

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

And then in the layout just define a view with background as dash_line. Note to include android:layerType="software", otherwise it won't work.

<View
            android:layout_width="match_parent"
            android:layout_height="5dp"
            android:background="@drawable/dash_line"
            android:layerType="software" />

I have custom a dashline which support horizontal&verical dash line . code below:

public class DashedLineView extends View
{
private float density;
private Paint paint;
private Path path;
private PathEffect effects;

public DashedLineView(Context context)
{
    super(context);
    init(context);
}

public DashedLineView(Context context, AttributeSet attrs)
{
    super(context, attrs);
    init(context);
}

public DashedLineView(Context context, AttributeSet attrs, int defStyle)
{
    super(context, attrs, defStyle);
    init(context);
}

private void init(Context context)
{
    density = DisplayUtil.getDisplayDensity(context);
    paint = new Paint();
    paint.setStyle(Paint.Style.STROKE);
    paint.setStrokeWidth(density * 4);
    //set your own color
    paint.setColor(context.getResources().getColor(R.color.XXX));
    path = new Path();
    //array is ON and OFF distances in px (4px line then 2px space)
    effects = new DashPathEffect(new float[] { 4, 2, 4, 2 }, 0);

}

@Override
protected void onDraw(Canvas canvas)
{
    // TODO Auto-generated method stub
    super.onDraw(canvas);
    paint.setPathEffect(effects);
    int measuredHeight = getMeasuredHeight();
    int measuredWidth = getMeasuredWidth();
    if (measuredHeight <= measuredWidth)
    {
        // horizontal
        path.moveTo(0, 0);
        path.lineTo(measuredWidth, 0);
        canvas.drawPath(path, paint);
    }
    else
    {
        // vertical
        path.moveTo(0, 0);
        path.lineTo(0, measuredHeight);
        canvas.drawPath(path, paint);
    }

}
}