如何在 Android 中制作虚线/虚线？

Question

我正在尝试画一条虚线。我现在正在使用它作为实线：

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，但点而不是实心。我想避免在透明布局和实体布局之间交替使用数百个布局。

Answer 1

没有java代码：

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" />

效果：

Answer 2

在绘制对象上设置路径效果

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

您可以通过在 int[] 数组中提供更多数字来创建各种点状图案，它指定了破折号和间隙的比率。这是一条简单的同样虚线。

Answer 3

使用 XML 创建虚线。
在 drawable 文件夹中创建 xml 并将该背景赋予要设置虚线边框的项目。

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>

为项目添加背景：

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

Answer 4

创建 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>

设置为视图的背景：

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

Answer 5

当我想画虚线时，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背景为 dash_line 的视图。注意要包含android:layerType="software"，否则不起作用。

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

Answer 6

我自定义了一个支持水平和垂直虚线的虚线。代码如下：

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);
    }

}
}

Answer 7

如果您正在寻找一条垂直线，请使用此可绘制对象。

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item
        android:top="-8dp"
        android:bottom="-8dp"
        android:left="-8dp">
        <shape>
            <solid android:color="@android:color/transparent"/>
            <stroke
                android:width="4dp"
                android:color="#ffffff"
                android:dashGap="4dp"
                android:dashWidth="4dp"/>
        </shape>
    </item>
</layer-list>

负的 top bottom 和 left 值删除了形状不需要的边，留下一条虚线。

在这样的视图中使用它。

<View
android:layout_width="4dp"
android:layout_height="match_parent"
android:background="@drawable/dash_line_vertical"
android:layerType="software" />

Answer 8

通过使用此类，您可以将“虚线和下划线”效果应用于多行文本。要使用 DashPathEffect，您必须关闭 TextView 的 hardwareAccelerated（尽管 DashPathEffect 方法存在长文本问题）。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：

Answer 9

对于画布上的虚线效果，将此属性设置为绘画对象：

paint.setPathEffect(new DashPathEffect(new float[] {0,30}, 0));

并根据您的渲染情况更改值 30：它代表每个点之间的“距离”。

Answer 10

我使用以下作为布局的背景：

<?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>

Answer 11

我为 EditText 创建了点划线。干得好。 创建新的 xml。例如 dashed_border.xml 这里的代码：

<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
<item
    android:bottom="1dp"
    android:left="-2dp"
    android:right="-2dp"
    android:top="-2dp">
    <shape android:shape="rectangle">
        <stroke
            android:width="2dp"
            android:color="#000000"
            android:dashGap="3dp"
            android:dashWidth="1dp" />

        <solid android:color="#00FFFFFF" />

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

并在 EditText 中使用新的 xml 文件，例如：

<EditText
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@drawable/dashed_border"/>

干杯！ :)

Answer 12

使用 ShapeDrawable 代替 LinearLayout 并使用 dashWidth 和 dashGap

http://developer.android.com/guide/topics/resources/drawable-resource.html#Shape

Answer 13

完美运行虚线背景的最佳解决方案

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

Answer 14

我喜欢Ruidge 的解决方案，但我需要更多来自 XML 的控制。所以我把它改成了 Kotlin 并添加了属性。

1) 复制 Kotlin 类：

import android.content.Context
import android.graphics.*
import android.util.AttributeSet
import android.view.View

class DashedDividerView : View {
constructor(context: Context) : this(context, null, 0)
constructor(context: Context, attributeSet: AttributeSet) : this(context, attributeSet, 0)

companion object {
    const val DIRECTION_VERTICAL = 0
    const val DIRECTION_HORIZONTAL = 1
}

private var dGap = 5.25f
private var dWidth = 5.25f
private var dColor = Color.parseColor("#EE0606")
private var direction = DIRECTION_HORIZONTAL
private val paint = Paint()
private val path = Path()

constructor(context: Context, attrs: AttributeSet?, defStyleAttr: Int) : super(
    context,
    attrs,
    defStyleAttr
) {
    val typedArray = context.obtainStyledAttributes(
        attrs,
        R.styleable.DashedDividerView,
        defStyleAttr,
        R.style.DashedDividerDefault
    )

    dGap = typedArray.getDimension(R.styleable.DashedDividerView_dividerDashGap, dGap)
    dWidth = typedArray.getDimension(R.styleable.DashedDividerView_dividerDashWidth, dWidth)
    dColor = typedArray.getColor(R.styleable.DashedDividerView_dividerDashColor, dColor)
    direction =
        typedArray.getInt(R.styleable.DashedDividerView_dividerDirection, DIRECTION_HORIZONTAL)

    paint.color = dColor
    paint.style = Paint.Style.STROKE
    paint.pathEffect = DashPathEffect(floatArrayOf(dWidth, dGap), 0f)
    paint.strokeWidth = dWidth

    typedArray.recycle()
}

override fun onDraw(canvas: Canvas) {
    super.onDraw(canvas)
    path.moveTo(0f, 0f)

    if (direction == DIRECTION_HORIZONTAL) {
        path.lineTo(measuredWidth.toFloat(), 0f)
    } else {
        path.lineTo(0f, measuredHeight.toFloat())
    }
    canvas.drawPath(path, paint)
}

}

2) 在 /res 目录下创建一个 attr 文件并添加这个

 <declare-styleable name="DashedDividerView">
    <attr name="dividerDashGap" format="dimension" />
    <attr name="dividerDashWidth" format="dimension" />
    <attr name="dividerDashColor" format="reference|color" />
    <attr name="dividerDirection" format="enum">
        <enum name="vertical" value="0" />
        <enum name="horizontal" value="1" />
    </attr>
</declare-styleable>

3) 将样式添加到 styles 文件

 <style name="DashedDividerDefault">
    <item name="dividerDashGap">2dp</item>
    <item name="dividerDashWidth">2dp</item>
    <!-- or any color -->
    <item name="dividerDashColor">#EE0606</item>
    <item name="dividerDirection">horizontal</item>
</style>

4) 现在可以使用默认样式了

<!-- here will be your path to the class -->
<com.your.package.app.DashedDividerView
    android:layout_width="match_parent"
    android:layout_height="2dp"
    />

或在 XML 中设置属性

<com.your.package.app.DashedDividerView
    android:layout_width="match_parent"
    android:layout_height="2dp"
    app:dividerDirection="horizontal"
    app:dividerDashGap="2dp"
    app:dividerDashWidth="2dp"
    app:dividerDashColor="@color/light_gray"/>

Answer 15

这些答案都不适合我。这些答案中的大多数都给你一个半透明的边框。为避免这种情况，您需要用另一个具有您喜欢的颜色的容器再次包裹您的容器。这是一个例子：

This is how it looks

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&#10;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>

Answer 16

唯一对我有用并且我认为这是最简单的方法是使用带有这样的绘画对象的路径：

    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()：（如果你在 ondraw 调用之间更改这些点，重要的调用重置，导致 Path 保存所有动作）

    pathDashLine.reset();
    pathDashLine.moveTo(porigenX, porigenY);
    pathDashLine.lineTo(cursorX,cursorY);
    c.drawPath(pathDashLine, paintDash);

Answer 17

我不知道为什么，但投票的答案对我不起作用。我这样写，效果很好。
定义自定义视图：

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"/>

Answer 18

我创建了一个带有自定义视图的库来解决这个问题，它应该非常易于使用。有关更多信息，请参阅https://github.com/Comcast/DahDit。您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"/>

Answer 19

类似于tier777，这里有一个水平线的解决方案：

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <item android:top="-1dp">
        <shape android:shape="line">
            <stroke
                android:width="1dp"
                android:color="#111"
                android:dashWidth="8dp"
                android:dashGap="2dp"
                />
            <solid android:color="@android:color/transparent" />
        </shape>
    </item>
</layer-list>

线索是<item android:top="-1dp">。

为了在旧设备 (android:layerType="software" 创建一个视图（请参阅 Android dashed line drawable potential ICS bug）：

<?xml version="1.0" encoding="utf-8"?>
<View xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="@drawable/dashed_line"
    android:layerType="software"
    />

您还可以将不带android:layerType="software" 的相同视图添加到layout-v23 以获得更好的性能，但我不确定它是否适用于所有具有API 23 的设备。