17

我想在 TextView 中显示一个有序列表，例如：
1）第 1 项
2） 第 2 项

使用以下布局：

<TextView
    android:text="<ol><li>item 1\n</li><li>item 2\n</li></ol>
    />

我得到：

  • 第 1 项
  • 第 2 项

如何将项目符号更改为数字？

谢谢。

4

8 回答 8

14

我认为您必须在代码中执行此操作。我必须继承LeadingMarginSpan 才能让它工作。这是我的做法。

private class NumberIndentSpan implements LeadingMarginSpan {

    private final int gapWidth;
    private final int leadWidth;
    private final int index;

    public NumberIndentSpan(int leadGap, int gapWidth, int index) {
        this.leadWidth = leadGap;
        this.gapWidth = gapWidth;
        this.index = index;
    }

    public int getLeadingMargin(boolean first) {
        return leadWidth + gapWidth;
    }

    public void drawLeadingMargin(Canvas c, Paint p, int x, int dir, int top, int baseline, int bottom, CharSequence text, int start, int end, boolean first, Layout l) {
        if (first) {
            Paint.Style orgStyle = p.getStyle();
            p.setStyle(Paint.Style.FILL);
            float width = p.measureText("4.");
            c.drawText(index + ".", (leadWidth + x - width / 2) * dir, bottom - p.descent(), p);
            p.setStyle(orgStyle);
        }
    }
}

掌握你的观点，并像这样使用它：

SpannableStringBuilder content = new SpannableStringBuilder();
for(String text : list) {
    int contentStart = content.length();
    content.append(text);
    content.setSpan(new NumberIndentSpan(15, 15, number), contentStart, content.length(), 0);
}

TextView view = findViewById(R.id.....);
view.setText(content);
于 2014-12-18T07:22:59.277 回答
4

我按照@jk2K的回答进行了回答，并对 他的代码进行了修改。因为我需要为每个项目符号点缩进，

String[] textArray = {
    "dfsdljjlfsdsdfjsdjldssdfidfsjdljasdfjfds\n",
    "sdfjdfjlkfdjdfkfjiwejojodljfldsjodsjfsdjdlf\n",
    "djsdfjsdffjdflljfjsadfdjfldfjl"
};

SpannableStringBuilder content = new SpannableStringBuilder();
int number = 1;
for (String t1 : textArray) {
    int contentStart = content.length();

    content.append(t1);

    int contentEnd = content.length();
    content.setSpan(
            new BulletSpan(10),
            contentStart,
            contentEnd,
            Spannable.SPAN_INCLUSIVE_EXCLUSIVE
    );

    number++;
}

我使用了android 库中的 BulletSpan 类，并new LeadingMarginSpan.Standard(0, 66)用new BulletSpan(10)它创建了一个具有宽度的 BulletSpan。如BulletSpan 类文档中所述

BulletSpan(int gapWidth)

Creates a BulletSpan based on a gap width

因此，您不再需要附加@jk2K 的答案中提到的项目符号，

 String leadingString = number + ". ";
 content.append(leadingString);
于 2019-01-13T21:27:50.290 回答
3

  1. 转到 res/values/strings.xml 然后粘贴下面的代码

    <string name="list">
  <li>1) Item 1</li>\n
  <li>2) Item 2</li>\n
  <li>3) Item 3</li>\n
</string>

  2. 然后转到包含 TextView 的布局文件并替换为以下代码

    <TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="@string/list" />
于 2018-03-11T10:14:20.920 回答
2

您可以改用这种方式：

&#8226; foo<br/>
&#8226; bar<br/>
&#8226; baz<br/>
于 2013-05-19T04:01:36.627 回答
1

我们可以直接使用LeadingMarginSpan

例如

String[] textArray = {
    "dfsdljjlfsdsdfjsdjldssdfidfsjdljasdfjfds\n",
    "sdfjdfjlkfdjdfkfjiwejojodljfldsjodsjfsdjdlf\n",
    "djsdfjsdffjdflljfjsadfdjfldfjl"
};

SpannableStringBuilder content = new SpannableStringBuilder();
int number = 1;
for (String t1 : textArray) {
    int contentStart = content.length();

    String leadingString = number + ". ";
    content.append(leadingString);
    content.append(t1);

    int contentEnd = content.length();
    content.setSpan(
            new LeadingMarginSpan.Standard(0, 66),
            contentStart,
            contentEnd,
            Spannable.SPAN_INCLUSIVE_EXCLUSIVE
    );

    number++;
}
于 2017-06-20T07:58:17.907 回答
1

这是我使用的解决方案。您可以将其复制并粘贴到活动中以查看其工作方式，但您应该使用变量更改所有属性以进行生产。您可以根据需要使用填充参数来缩进它。如果您想要项目符号列表，您可以使用项目符号字符而不是数字。

<LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >

            <TextView
                android:id="@+id/bullet1"
                android:textStyle="bold"
                android:layout_width="30dp"
                android:gravity="right"
                android:layout_height="wrap_content"
                android:paddingRight="5dp"
                android:text="1"
                android:textSize="20dp" />

            <TextView
                android:id="@+id/bullet1Text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="10dp"
                android:text="First bullet. First bullet. First bullet. First bullet. First bullet. First bullet. First bullet. First bullet. "
                android:textSize="15dp" />
        </LinearLayout>



        <LinearLayout
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal" >

            <TextView
                android:id="@+id/bullet2"
                android:textStyle="bold"
                android:layout_width="30dp"
                android:gravity="right"
                android:layout_height="wrap_content"
                android:paddingRight="5dp"
                android:text="2"
                android:textSize="20dp" />

            <TextView
                android:id="@+id/bullet2Text"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:paddingBottom="10dp"
                android:text="Second bullet. Second bullet. Second bullet. Second bullet. Second bullet. Second bullet. Second bullet. "
                android:textSize="15dp" />
        </LinearLayout>
于 2015-08-06T23:16:13.410 回答
0

此类处理 TextView 和 EditText 中的编号，并根据文本的大小缩放数字：

import android.graphics.Canvas
import android.graphics.Paint
import android.text.Layout
import android.text.Spanned
import android.text.style.AbsoluteSizeSpan
import android.text.style.LeadingMarginSpan

/**
 * Paragraph numbering.
 *
 *
 * Android seems to add the leading margin for an empty paragraph to the previous paragraph
 * (]0, 4][4, 4] --> the leading margin of the second span is added to the ]0, 4] paragraph
 * regardless of the Spanned.flags) --> therefore we ignore the leading margin for the last,
 * empty paragraph unless it's the only one
 */
class NumberSpan(nr: Int, gapWidth: Int, isEmpty: Boolean, isFirst: Boolean, isLast: Boolean)
    : LeadingMarginSpan {

    private val mNr: Int = nr
    private val mGapWidth: Int = gapWidth
    private val mIgnoreSpan: Boolean = isEmpty && isLast && !isFirst

    private var mWidth: Float = 0.toFloat()

    val value: Boolean?
        get() = java.lang.Boolean.TRUE

    override fun getLeadingMargin(first: Boolean): Int {
        return if (mIgnoreSpan) 0 else Math.max(Math.round(mWidth + 2), mGapWidth)
    }

    override fun drawLeadingMargin(c: Canvas, p: Paint, x: Int, dir: Int, top: Int, baseline: Int, bottom: Int,
                                   text: CharSequence, start: Int, end: Int, first: Boolean, l: Layout) {

        val spanned = text as Spanned
        if (!mIgnoreSpan && spanned.getSpanStart(this) == start) {
            // set paint
            val oldStyle = p.style
            val oldTextSize = p.textSize
            p.style = Paint.Style.FILL
            val textSize = determineTextSize(spanned, start, end, oldTextSize)
            p.textSize = textSize
            mWidth = p.measureText(mNr.toString() + ".")

            // draw the number
            c.drawText(mNr.toString() + ".", x.toFloat(), baseline.toFloat(), p)

            // restore paint
            p.style = oldStyle
            p.textSize = oldTextSize
        }
    }

    private fun determineTextSize(spanned: Spanned, start: Int, end: Int, defaultTextSize: Float): Float {
        // If the text size is different from default use that to determine the indicator size
        // That is determined by finding the first visible character within the list item span
        // and checking its size
        val position = firstVisibleCharIndex(spanned, start, end)
        if (position >= 0) {
            val absoluteSizeSpans = spanned.getSpans(position, position, AbsoluteSizeSpan::class.java)
            if (absoluteSizeSpans.isNotEmpty()) {
                val absoluteSizeSpan = absoluteSizeSpans[absoluteSizeSpans.size - 1]
                return absoluteSizeSpan.size.toFloat()
            }
        }

        // If there are no spans or no visible characters yet use the default calculation
        return defaultTextSize
    }

    private fun firstVisibleCharIndex(spanned: Spanned, start: Int, end: Int): Int {
        var newStart = start
        while (newStart < end) {
            if (isVisibleChar(spanned[newStart])) {
                return newStart
            }
            newStart++
        }

        return -1
    }

    private fun isVisibleChar(c: Char): Boolean {
        return when (c) {
            '\u200B', '\uFFEF' -> false
            else -> true
        }
    }

}

代码来自这个库https://github.com/1gravity/Android-RTEditor（从 Java 翻译成 Kotlin）。我是那个图书馆的作者。

于 2018-05-15T01:22:15.203 回答
0

遵循@Håvard 的回答并面临与@Vivek modi 相同的问题，我实现了下一个工作解决方案，该解决方案考虑了自定义字体+行间距附加功能，并用 Kotlin 编写：

https://gist.github.com/marcelpallares/ae6285ee0dcb3f04493991dcb18d01bd

class NumberIndentSpan(
    private val number: Int,
    private val leadWidth: Int = 15,
    private val gapWidth: Int = 30,
) : LeadingMarginSpan {
    override fun getLeadingMargin(first: Boolean): Int {
        return leadWidth + gapWidth
    }

    override fun drawLeadingMargin(
        canvas: Canvas,
        paint: Paint,
        x: Int,
        dir: Int,
        top: Int,
        baseline: Int,
        bottom: Int,
        t: CharSequence?,
        start: Int,
        end: Int,
        first: Boolean,
        layout: Layout?
    ) {
        if (first) {
            val text = "$number."
            val width = paint.measureText(text)

            val yPosition = baseline.toFloat()
            val xPosition = (leadWidth + x - width / 2) * dir

            canvas.drawText(text, xPosition, yPosition, paint)
        }
    }
}

我还添加了一个扩展方法来使用它：

fun TextView.setNumberedText(list: List<String>) {
    val content = SpannableStringBuilder()
    val gap = context.resources.getDimensionPixelSize(R.dimen.margin_16)

    list.forEachIndexed { index, text ->
        val contentStart = content.length
        content.appendLine(text)
        content.setSpan(NumberIndentSpan(index + 1, gapWidth = gap), contentStart, content.length, 0)
    }

    text = content
}

最后一个自定义 TextView 能够从 XML 布局中使用它

class OrderedListTextView @JvmOverloads constructor(
    context: Context, attrs: AttributeSet? = null
) : AppCompatTextView(context, attrs) {

    init {
        setNumberedText(text.lines())
    }
}
于 2021-12-08T12:03:05.220 回答