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);
}
}
}
其他回答
无需java代码:
可拉的/ 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" />
效果:
使用XML创建虚线。 在可绘制文件夹中创建xml，并给你想要设置虚线边界的项目提供背景。
创建XML背景"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>
添加背景到项目:
<Button
android:id="@+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="@drawable/dashed_border"/>
这些答案对我都没用。大多数答案都给出了一个半透明的边框。为了避免这种情况，您需要再次用另一个具有您喜欢的颜色的容器包装您的容器。这里有一个例子:
这就是它的样子
dashed_border_layout.xml
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:backgroundTint="@color/black"
android:background="@drawable/dashed_border_out">
<LinearLayout
android:layout_width="150dp"
android:layout_height="50dp"
android:padding="5dp"
android:background="@drawable/dashed_border_in"
android:orientation="vertical">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="This is Dashed Container"
android:textSize="16sp" />
</LinearLayout>
dashed_border_in.xml
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item>
<shape>
<corners android:radius="10dp" />
<solid android:color="#ffffff" />
<stroke
android:dashGap="5dp"
android:dashWidth="5dp"
android:width="3dp"
android:color="#0000FF" />
<padding
android:bottom="5dp"
android:left="5dp"
android:right="5dp"
android:top="5dp" />
</shape>
</item>
dashed_border_out.xml
<layer-list xmlns:android="http://schemas.android.com/apk/res/android" >
<item>
<shape>
<corners android:radius="12dp" />
</shape>
</item>
唯一对我有用的方法，我认为这是最简单的方法，就是使用Path和一个paint对象，就像这样:
Paint paintDash = new Paint();
paintDash.setARGB(255, 0, 0, 0);
paintDash.setStyle(Paint.Style.STROKE);
paintDash.setPathEffect(new DashPathEffect(new float[]{10f,10f}, 0));
paintDash.setStrokeWidth(2);
Path pathDashLine = new Path();
然后onDraw():(重要调用重置，如果你改变这些点之间的onDraw调用，导致路径保存所有的移动)
pathDashLine.reset();
pathDashLine.moveTo(porigenX, porigenY);
pathDashLine.lineTo(cursorX,cursorY);
c.drawPath(pathDashLine, paintDash);
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" />
