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
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:
其他回答
我已经创建了一个带有自定义视图的库来解决这个问题，它使用起来应该非常简单。详见https://github.com/Comcast/DahDit。你可以像这样添加虚线:
<com.xfinity.dahdit.DashedLine
android:layout_width="250dp"
android:layout_height="wrap_content"
app:dashHeight="4dp"
app:dashLength="8dp"
app:minimumDashGap="3dp"
app:layout_constraintRight_toRightOf="parent"
android:id="@+id/horizontal_dashes"/>
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:
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);
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:
对于画布上的点状效果，将此属性设置为paint对象:
paint.setPathEffect(new DashPathEffect(new float[] {0,30}, 0));
并根据你的渲染效果改变值30:它代表每个点之间的“距离”。
