29

有没有办法调整 Android 中字符之间的间距TextView?我相信这通常被称为“字距调整”。

我知道该android:textScaleX属性,但这会压缩字符和间距。

4

12 回答 12

71

我构建了一个自定义类,它扩展了 TextView 并添加了一个方法“setSpacing”。解决方法类似于@Noah 所说的。该方法在字符串的每个字母之间添加一个空格,并使用SpannedString更改空格的 TextScaleX,允许正负间距。

希望对某人有所帮助^^

/**
 * Text view that allows changing the letter spacing of the text.
 * 
 * @author Pedro Barros (pedrobarros.dev at gmail.com)
 * @since May 7, 2013
 */

import android.content.Context;
import android.text.Spannable;
import android.text.SpannableString;
import android.text.style.ScaleXSpan;
import android.util.AttributeSet;
import android.widget.TextView;

public class LetterSpacingTextView extends TextView {

    private float spacing = Spacing.NORMAL;
    private CharSequence originalText = "";


    public LetterSpacingTextView(Context context) {
        super(context);
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs){
        super(context, attrs);
    }

    public LetterSpacingTextView(Context context, AttributeSet attrs, int defStyle){
        super(context, attrs, defStyle);
    }

    public float getSpacing() {
        return this.spacing;
    }

    public void setSpacing(float spacing) {
        this.spacing = spacing;
        applySpacing();
    }

    @Override
    public void setText(CharSequence text, BufferType type) {
        originalText = text;
        applySpacing();
    }

    @Override
    public CharSequence getText() {
        return originalText;
    }

    private void applySpacing() {
        if (this == null || this.originalText == null) return;
        StringBuilder builder = new StringBuilder();
        for(int i = 0; i < originalText.length(); i++) {
            builder.append(originalText.charAt(i));
            if(i+1 < originalText.length()) {
                builder.append("\u00A0");
            }
        }
        SpannableString finalText = new SpannableString(builder.toString());
        if(builder.toString().length() > 1) {
            for(int i = 1; i < builder.toString().length(); i+=2) {
                finalText.setSpan(new ScaleXSpan((spacing+1)/10), i, i+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
            }
        }
        super.setText(finalText, BufferType.SPANNABLE);
    }

    public class Spacing {
        public final static float NORMAL = 0;
    }
}

使用它:

LetterSpacingTextView textView = new LetterSpacingTextView(context);
textView.setSpacing(10); //Or any float. To reset to normal, use 0 or LetterSpacingTextView.Spacing.NORMAL
textView.setText("My text");
//Add the textView in a layout, for instance:
((LinearLayout) findViewById(R.id.myLinearLayout)).addView(textView);
于 2013-05-07T22:40:05.250 回答
14

如果有人正在寻找一种简单的方法来将字距调整应用于任何字符串(技术上,CharSequence)而不使用TextView

public static Spannable applyKerning(CharSequence src, float kerning)
{
    if (src == null) return null;
    final int srcLength = src.length();
    if (srcLength < 2) return src instanceof Spannable
                              ? (Spannable)src
                              : new SpannableString(src);

    final String nonBreakingSpace = "\u00A0";
    final SpannableStringBuilder builder = src instanceof SpannableStringBuilder
                                           ? (SpannableStringBuilder)src
                                           : new SpannableStringBuilder(src);
    for (int i = src.length() - 1; i >= 1; i--)
    {
        builder.insert(i, nonBreakingSpace);
        builder.setSpan(new ScaleXSpan(kerning), i, i + 1,
                        Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
    }

    return builder;
}
于 2013-11-29T19:59:04.853 回答
12

AFAIK,您无法在TextView. Canvas如果您使用 2D 图形 API在自己上绘制文本,则可以调整字距。

于 2009-10-29T14:18:27.583 回答
5

从 Android 21 开始,您可以使用设置letterSpacing属性。

<TextView
    android:width="..."
    android:height="..."
    android:letterSpacing="1.3"/>
于 2019-06-18T07:53:37.057 回答
4

这是我的解决方案,它在每个字符之间添加了统一的间距(以像素为单位)。此跨度假定所有文本都在一行中。这基本上实现了@commonsWare 的建议。

SpannableStringBuilder builder = new SpannableStringBuilder("WIDE normal");
builder.setSpan(new TrackingSpan(20), 0, 4, Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
...

private static class TrackingSpan extends ReplacementSpan {
    private float mTrackingPx;

    public TrackingSpan(float tracking) {
        mTrackingPx = tracking;
    }

    @Override
    public int getSize(Paint paint, CharSequence text, 
        int start, int end, Paint.FontMetricsInt fm) {
        return (int) (paint.measureText(text, start, end) 
            + mTrackingPx * (end - start - 1));
    }

    @Override
    public void draw(Canvas canvas, CharSequence text, 
        int start, int end, float x, int top, int y, 
        int bottom, Paint paint) {
        float dx = x;
        for (int i = start; i < end; i++) {
            canvas.drawText(text, i, i + 1, dx, y, paint);
            dx += paint.measureText(text, i, i + 1) + mTrackingPx;
        }
    }
}
于 2014-07-15T23:29:07.530 回答
3

我发现调整字距的唯一方法是创建一个自定义字体,其中字形推进被改变。

于 2013-01-10T11:01:13.810 回答
2

当您使用 TextView 时,很难调整字符之间的间距。但是,如果您可以自己处理绘图,则应该有某种方法可以做到这一点。

我对这个问题的回答是: 使用您的自定义 Span

我的代码:

public class LetterSpacingSpan extends ReplacementSpan {
    private int letterSpacing = 0;

    public LetterSpacingSpan spacing(int space) {
        letterSpacing = space;

        return this;
    }


    @Override
    public int getSize(@NonNull Paint paint, CharSequence text, int start, int end, @Nullable Paint.FontMetricsInt fm) {
        return (int) paint.measureText(text, start, end) + (text.length() - 1) * letterSpacing;
    }


    @Override
    public void draw(@NonNull Canvas canvas, CharSequence text, int start, int end, float x, int top, int y, int bottom, @NonNull Paint paint) {
        int length = text.length();
        float currentX = x;

        for (int i = 1; i < length; i++) {          
            canvas.drawText(text, i, i + 1, currentX, y, paint);
            currentX += paint.measureText(text, i, i + 1) + letterSpacing;
         }
    }
}

解释:

构建你自己的Span可以帮助你实现许多惊人的效果,比如制作一个模糊的 TextView,改变你的 TextView 的背景或前景,甚至制作一些动画。我从这篇文章中学到了很多东西跨越一个强大的概念

因为您要为每个字符添加间距,所以我们应该使用字符级别的基本跨度,在这种情况下,ReplacementSpan 是最佳选择。我添加了一个spacing方法,因此在使用它时,您可以简单地将每个字符所需的空格作为参数传递。

在构建自定义跨度时,您需要覆盖至少两个方法,getSize并且draw. 在我们为整个字符序列添加间距后,该getSize方法应该返回最终宽度,并且在draw方法块内,您可以控制Canvas进行您想要的绘图。

那么我们如何使用这个 LetterSpacingSpan 呢?这简单:

用法:

TextView textView;
Spannable content = new SpannableString("This is the content");
textView.setSpan(new LetterSpacingSpan(), 0, 4, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
textView.setText(content);

就是这样。

于 2018-06-14T08:22:15.903 回答
1

您也可以尝试使用SpannedString但您需要对其进行解析并更改每个单词的字符间距

于 2011-01-25T23:27:34.077 回答
1

这个答案可能对想要使用 drawText 在 Canvas 上使用字距绘制文本的人有所帮助(这与 TextView 中的文本无关)。

从 Lollipop 开始,方法 setLetterSpacing 在 Paint 上可用。如果 SDK 是 LOLLIPOP 和 on,则使用 setLetterSpacing。否则,将调用一个类似于@dgmltn 上述建议的方法:

    if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.LOLLIPOP) {
        paint.setLetterSpacing(-0.04f);  // setLetterSpacing is only available from LOLLIPOP and on
        canvas.drawText(text, xOffset, yOffset, paint);
    } else {
        float spacePercentage = 0.05f;
        drawKernedText(canvas, text, xOffset, yOffset, paint, spacePercentage);
    }


/**
 * Programatically drawn kerned text by drawing the text string character by character with a space in between.
 * Return the width of the text.
 * If canvas is null, the text won't be drawn, but the width will still be returned
 * kernPercentage determines the space between each letter. If it's 0, there will be no space between letters.
 * Otherwise, there will be space between each letter. The  value is a fraction of the width of a blank space.
 */
private int drawKernedText(Canvas canvas, String text, float xOffset, float yOffset, Paint paint, float kernPercentage) {
    Rect textRect = new Rect();
    int width = 0;
    int space = Math.round(paint.measureText(" ") * kernPercentage);
    for (int i = 0; i < text.length(); i++) {
        if (canvas != null) {
            canvas.drawText(String.valueOf(text.charAt(i)), xOffset, yOffset, paint);
        }
        int charWidth;
        if (text.charAt(i) == ' ') {
            charWidth = Math.round(paint.measureText(String.valueOf(text.charAt(i)))) + space;
        } else {
            paint.getTextBounds(text, i, i + 1, textRect);
            charWidth = textRect.width() + space;
        }
        xOffset += charWidth;
        width += charWidth;
    }
    return width;
}
于 2016-03-27T06:21:43.033 回答
0

@Pedro Barros 的答案有一个小编辑。如果您使用 SpannableString 来设置它,它会很有用,例如,如果您想为某些字符制作不同的颜色:

private void applySpacing() {
    SpannableString finalText;

    if (!(originalText instanceof SpannableString)) {
        if (this.originalText == null) return;
        StringBuilder builder = new StringBuilder();
        for (int i = 0; i < originalText.length(); i++) {
            builder.append(originalText.charAt(i));
            if (i + 1 < originalText.length()) {
                builder.append("\u00A0");
            }
        }
        finalText = new SpannableString(builder.toString());
    } else {
        finalText = (SpannableString) originalText;
    }

    for (int i = 1; i < finalText.length(); i += 2) {
        finalText.setSpan(new ScaleXSpan((spacing + 1) / 10), i, i + 1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
    }
    super.setText(finalText, TextView.BufferType.SPANNABLE);
}
于 2015-10-01T09:44:40.320 回答
0

我想使用@PedroBarros 答案,但是通过定义间距应该是像素。

这是我对 applySpacing 方法的编辑:

private void applySpacing() {
    if (this == null || this.originalText == null) return;

    Paint testPaint = new Paint();
    testPaint.set(this.getPaint());
    float spaceOriginalSize = testPaint.measureText("\u00A0");
    float spaceScaleXFactor = ( spaceOriginalSize > 0 ? spacing/spaceOriginalSize : 1);

    StringBuilder builder = new StringBuilder();
    for(int i = 0; i < originalText.length(); i++) {
        builder.append(originalText.charAt(i));
        if(i+1 < originalText.length()) {
            builder.append("\u00A0");
        }
    }
    SpannableString finalText = new SpannableString(builder.toString());
    if(builder.toString().length() > 1) {
        for(int i = 1; i < builder.toString().length(); i+=2) {
            finalText.setSpan(new ScaleXSpan(spaceScaleXFactor), i, i+1, Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
    }
    super.setText(finalText, BufferType.SPANNABLE);
}

我是 Android 开发人员的初学者,如果这不好,请随时告诉我!

于 2015-10-20T18:57:41.520 回答
0

另一种解决方案。

public static SpannableStringBuilder getSpacedSpannable(Context context, String text, int dp) {
        if (text == null) return null;
        if (dp < 0) throw new RuntimeException("WRONG SPACING " + dp);
        Canvas canvas = new Canvas();
        Drawable drawable = ContextCompat.getDrawable(context, R.drawable.pixel_1dp);
        Bitmap main = Bitmap.createBitmap(drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight(), Bitmap.Config.ARGB_8888);
        canvas.setBitmap(main);
        drawable.setBounds(0, 0, drawable.getIntrinsicWidth(), drawable.getIntrinsicHeight());
        drawable.draw(canvas);
        SpannableStringBuilder builder = new SpannableStringBuilder();
        char[] array = text.toCharArray();
        Bitmap bitmap = Bitmap.createScaledBitmap(main, dp * main.getWidth(), main.getHeight(), false);
        for (char ch : array) {
            builder.append(ch);
            builder.append(" ");
            ImageSpan imageSpan = new ImageSpan(context, bitmap);
            builder.setSpan(imageSpan, builder.length() - 1, builder.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
        }
        return builder;
    }

其中 pixel_1dp 是 XML:

<?xml version="1.0" encoding="utf-8"?>
<shape xmlns:android="http://schemas.android.com/apk/res/android">

    <solid android:color="@android:color/transparent"/>
    <size android:height="1dp" android:width="1dp"/>

</shape>

要设置间距,请使用如下代码:

textView.setText(getSpacedSpannable(context, textView.getText().toString(), <Your spacing DP>), TextView.BufferType.SPANNABLE);
于 2017-03-21T04:25:26.960 回答