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

我喜欢Ruidge的解决方案,但我需要XML提供更多的控制。所以我把它改为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

 <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)在styles文件中添加一个样式

 <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)现在你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"
    />

或者在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"/>

其他回答

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:

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&#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>

使用ShapeDrawable代替LinearLayout,使用dashWidth和dashGap

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

我已经为EditText创建了虚线。给你。 创建新的xml。代码如下:

<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>

并使用您的新xml文件在您的EditText例如:

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

干杯!:)

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。