如何在TextView中的部分文本周围设置矩形虚线/虚线轮廓？

Question

背景

有很多方法可以为TextView中显示的部分文本设置样式,例如设置其前景色(此处)和其他(此处).

问题

我无法确定是否有办法在TextView 的部分文本上设置矩形虚线/虚线轮廓.像这样的东西:

我试过的

我试图寻找这样的解决方案,并且我也尝试阅读CharacterStyle的文档.尽管如此,我认为任何可用的跨度都不适合这种风格.

这个问题

是否有内置的解决方案,或者我是否需要使用自定义的实现？

---

我使用了下面建议的修改版本,它在POC上运行良好,但出于某种原因,在实际项目中,文本两侧的垂直虚线是粗体:

这是当前的代码:

要使用的字符串

<string name="text_to_format">test &#160;&#160;%1$s test</string>

使用代码

        final String textToDash="DASHED";
        String formattedStr = getString(R.string.text_to_format, textToDash+ "<bc/>");
        Spanned textToShow = Html.fromHtml(formattedStr, null, new TagHandler() {
            int start;

            @Override
            public void handleTag(final boolean opening, final String tag, Editable output, final XMLReader xmlReader) {
                switch (tag) {
                    case "bc":
                        if (!opening)
                            start = output.length() - textToDash.length();
                        break;
                    case "html":
                        if (!opening)
                            output.setSpan(
                                    new DrawableSpan(ResourcesCompat.getDrawable(getResources(), R.drawable.dashed_border_shape, null)),
                                    start, start + textToDash.length(), 0);
                }
            }
        });
        textView.setText(textToShow);

DrawableSpan

public class DrawableSpan extends ReplacementSpan {
    private Drawable mDrawable;
    private final Rect mPadding;

    public DrawableSpan(Drawable drawable) {
        super();
        mDrawable = drawable;
        mPadding = new Rect();
        mDrawable.getPadding(mPadding);
    }

    @Override
    public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {
        RectF rect = new RectF(x, top, x + measureText(paint, text, start, end), bottom);
        mDrawable.setBounds((int) rect.left - mPadding.left, (int) rect.top - mPadding.top, (int) rect.right + mPadding.right, (int) rect.bottom + mPadding.bottom);
        canvas.drawText(text, start, end, x, y, paint);
        mDrawable.draw(canvas);
    }

    @Override
    public int getSize(Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) {
        return Math.round(paint.measureText(text, start, end));
    }

    private float measureText(Paint paint, CharSequence text, int start, int end) {
        return paint.measureText(text, start, end);
    }
}

RES /抽拉/ dashed_border_shape.xml

<shape xmlns:android="http://schemas.android.com/apk/res/android"
       android:shape="rectangle">
    <padding
        android:bottom="1dp"
        android:left="4dp"
        android:right="4dp"
        android:top="1dp"/>
    <solid android:color="@android:color/transparent"/>
    <stroke
        android:width="2dp"
        android:color="#ff474747"
        android:dashGap="10px"
        android:dashWidth="10px"/>
</shape>

textView没有任何特殊之处:

            <TextView
                android:id="@+id/..."
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:layout_marginBottom="20dp"
                android:layout_marginLeft="8dp"
                android:layout_marginRight="8dp"
                android:layout_marginTop="30dp"
                android:gravity="center_horizontal"
                android:textSize="20sp"/>

我甚至为这个视图的多个父母设置了android:clipChildren ="false",android:clipToPadding ="false"(认为它没有像它试图那样绘制).什么都没有帮助.

怎么来,我该怎么做才能解决它？

Answer 1

解决方案1

1 - 为破折号创建一个drawable.像这样:

<shape android:shape="rectangle" xmlns:android="http://schemas.android.com/apk/res/android">
    <corners android:radius="5dp" />
    <solid android:color="@android:color/transparent" />
    <stroke
        android:color="@android:color/black"
        android:dashWidth="20px"
        android:dashGap="10px"
        android:width="3dp"/>
</shape>

2 - 将其设置为文本视图的背景,它可以只是一个单词.

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:padding="8dp">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello!"/>

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/button_shape"
        android:padding="4dp"
        android:text="world!"/>

</LinearLayout>

结果:

重要提示:此解决方案仅适用于小文本,例如在游戏中显示分数或小消息.它不会适应大文本.

解决方案2

如果您需要一个适用于大文本的更复杂的解决方案,您可以使用Spannable.

1 - >创建自定义ReplacementSpan

  public class DashedBorderSpan extends ReplacementSpan {

    private Drawable mDrawable;
    private int mPadding;


    public DashedBorderSpan(Drawable drawable, int padding) {
        super();

        mDrawable = drawable;
        mPadding = padding;
    }

    @Override
    public void draw(Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, Paint paint) {
        RectF rect = new RectF(x - mPadding, top - mPadding, x + measureText(paint, text, start, end) + mPadding, bottom + mPadding);

        mDrawable.setBounds((int) rect.left, (int)rect.top, (int)rect.right, (int)rect.bottom);

        canvas.drawText(text, start, end, x, y, paint);
        mDrawable.draw(canvas);
    }

    @Override
    public int getSize(Paint paint, CharSequence text, int start, int end, Paint.FontMetricsInt fm) {
        return Math.round(paint.measureText(text, start, end));
    }

    private float measureText(Paint paint, CharSequence text, int start, int end) {
        return paint.measureText(text, start, end);
    }
}

2 - >应用Spannable

TextView textView = (TextView) findViewById(R.id.textasd);

        String hello = "Dashed!";

        SpannableStringBuilder stringBuilder = new SpannableStringBuilder();

        stringBuilder.append(hello);
        stringBuilder.setSpan(new DrawableSpan(getDrawable(R.drawable.dashed_border_shape)),
                0,
                stringBuilder.length(),
                Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

        stringBuilder.append("not dashed... boring");

        textView.setText(stringBuilder);

该解决方案适用于所有情况.这是一个更好的解决方案,虽然它更复杂.

示例 如果您想将它与占位符一起使用,请使用如下所示:

    String someText = "Some Text!";

//R.string.placeholder = Hello: %s
            String formatedText = String.format(getString(R.string.placeholder), someText);

            SpannableStringBuilder stringBuilderPlaceHolder = new SpannableStringBuilder();
            stringBuilderPlaceHolder.append(formatedText);

            stringBuilderPlaceHolder.setSpan(new DashedBorderSpan(getDrawable(R.drawable.dashed_border_shape), 10),
                    formatedText.length() - someText.length(),
                    formatedText.length(),
                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

            textViewPlaceHolder.setText(stringBuilderPlaceHolder);

结果:

这样,跨度将仅设置在占位符上.如果你有一个更复杂的持有人使用相同的逻辑来实现你所需要的.

编辑

解决方案2存在一个小问题,但有一个解决方案.

你必须小心填充虚线边框drawable.如果在虚线边框中使用填充,则需要在使用Span的TextView中设置填充.在问题的作者提供的图像中,您可以看到上边线和下边线被切割(如果增加填充,线将完全消失),以避免在textview中使用填充.像这样:

<TextView
        android:id="@+id/text"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_marginBottom="20dp"
        android:layout_marginLeft="8dp"
        android:layout_marginRight="8dp"
        android:layout_marginTop="30dp"
        android:paddingTop="3dp" <!-- This will fix the problem!  -->
        android:paddingBottom="3dp" <!-- This will fix the problem!  -->
        android:gravity="center_horizontal"
        android:text="blabla"
        android:textSize="20sp"/>

这将解决问题=]快乐编码!