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
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" />
使用ShapeDrawable代替LinearLayout，使用dashWidth和dashGap
http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape
我不知道为什么，但投票的答案不适合我。我这样写，效果很好。 定义一个自定义视图:
public class XDashedLineView extends View {
private Paint mPaint;
private Path mPath;
private int vWidth;
private int vHeight;
public XDashedLineView(Context context) {
super(context);
init();
}
public XDashedLineView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public XDashedLineView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mPaint = new Paint();
mPaint.setColor(Color.parseColor("#3F577C"));
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setPathEffect(new DashPathEffect(new float[] {10,10}, 0));
mPath = new Path();
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
this.vWidth = getMeasuredWidth();
this.vHeight = getMeasuredHeight();
mPath.moveTo(0, this.vHeight / 2);
mPath.quadTo(this.vWidth / 2, this.vHeight / 2, this.vWidth, this.vHeight / 2);
}
@Override
protected void onDraw(Canvas canvas) {
super.onDraw(canvas);
canvas.drawPath(mPath, mPaint);
}
}
然后你可以在你的xml中使用它:
<com.YOUR_PACKAGE_NAME.XDashedLineView
android:layout_width="690dp"
android:layout_height="1dp"
android:layout_marginLeft="30dp"
android:layout_marginTop="620dp"/>
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);
}
}
}
通过使用这个类，您可以对多行文本应用“虚线和下划线”效果。使用dashpatheeffect你必须关闭你的TextView的hardwareAccelerated(虽然dashpatheeffect方法有一个长文本的问题)。你可以在这里找到我的示例项目:https://github.com/jintoga/Dashed-Underlined-TextView/blob/master/Untitled.png。
public class DashedUnderlineSpan implements LineBackgroundSpan, LineHeightSpan {
private Paint paint;
private TextView textView;
private float offsetY;
private float spacingExtra;
public DashedUnderlineSpan(TextView textView, int color, float thickness, float dashPath,
float offsetY, float spacingExtra) {
this.paint = new Paint();
this.paint.setColor(color);
this.paint.setStyle(Paint.Style.STROKE);
this.paint.setPathEffect(new DashPathEffect(new float[] { dashPath, dashPath }, 0));
this.paint.setStrokeWidth(thickness);
this.textView = textView;
this.offsetY = offsetY;
this.spacingExtra = spacingExtra;
}
@Override
public void chooseHeight(CharSequence text, int start, int end, int spanstartv, int v,
Paint.FontMetricsInt fm) {
fm.ascent -= spacingExtra;
fm.top -= spacingExtra;
fm.descent += spacingExtra;
fm.bottom += spacingExtra;
}
@Override
public void drawBackground(Canvas canvas, Paint p, int left, int right, int top, int baseline,
int bottom, CharSequence text, int start, int end, int lnum) {
int lineNum = textView.getLineCount();
for (int i = 0; i < lineNum; i++) {
Layout layout = textView.getLayout();
canvas.drawLine(layout.getLineLeft(i), layout.getLineBottom(i) - spacingExtra + offsetY,
layout.getLineRight(i), layout.getLineBottom(i) - spacingExtra + offsetY,
this.paint);
}
}
}
结果:
