我要画一条虚线。我现在用这个来画实线:

LinearLayout divider = new LinearLayout( this );
LinearLayout.LayoutParams params = new LinearLayout.LayoutParams( LinearLayout.LayoutParams.FILL_PARENT, 2 );
divider.setLayoutParams( params );
divider.setBackgroundColor( getResources().getColor( R.color.grey ) );

我需要这样的东西,但不是实心的,而是虚线的。我想避免在透明布局和固体布局之间交替制作数百个布局。


当前回答

我使用下面的作为布局的背景:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">
<stroke
   android:width="1dp"
    android:dashWidth="10px"
   android:dashGap="10px"
    android:color="android:@color/black" 
   />
</shape>

其他回答

我使用下面的作为布局的背景:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">
<stroke
   android:width="1dp"
    android:dashWidth="10px"
   android:dashGap="10px"
    android:color="android:@color/black" 
   />
</shape>

我自定义了一个虚线,支持水平和垂直虚线。下面的代码:

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);
    }

}
}

创建xml (view_line_dot .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>

设置为视图背景:

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

路径效果设置在绘制对象上

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

你可以通过在int[]数组中提供更多的数字来创建各种各样的点状图案,它指定了破折号和缺口的比例。这是一条简单的虚线。

当我想要绘制虚线时,我所做的是定义一个可绘制的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>

然后在布局中定义一个带背景的视图为dash_line。注意要包括android:layerType="software",否则它将无法工作。

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