如何在Android TextView中调整文本字距调整?

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

我知道android:textScaleX属性,但是压缩字符和间距。

Related of "如何在Android TextView中调整文本字距调整?"

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

我构建了一个扩展TextView的自定义类,并添加了一个方法“setSpacing”。 解决方法类似于@Noah所说的。 该方法在String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。

希望能帮助某人^^

 /** * 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); 

如果有人正在寻找一种简单的方法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; } 

我发现调整字距的唯一方法是创建一个自定义字体,其中字形前进被更改。

这是我的解决方案,它在每个字符之间添加均匀的间距(以像素为单位)。 此范围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; } } } 

您也可以尝试使用SpannedString但是您需要解析它并更改每个单词的字符间距

这个答案可能对想要使用drawText在Canvas上绘制文字的人有用(这不是关于TextView中的文本)。

从Lollipop开始,方法setLetterSpacing在Paint上可用。 如果SDK是LOLLIPOP并且打开,则使用setLetterSpacing。 否则,调用一个类似于@dgmltn上面建议的方法:

  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; } 

@Pedro Barros答案有一个小编辑。 如果您使用SpannableString来设置它,这很有用,例如,如果您想要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); } 

我想使用@PedroBarros答案,但是通过定义像素中的间距应该是什么。

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,如果不好,请随时告诉我!

还有一个解决方案

 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; } 

pixel_1dp是XML的位置:

 < ?xml version="1.0" encoding="utf-8"?>     

要设置间距,请使用以下代码:

 textView.setText(getSpacedSpannable(context, textView.getText().toString(), ), TextView.BufferType.SPANNABLE); 

在使用TextView时,很难调整字符之间的间距。 但是如果你能自己处理绘图,应该有一些方法可以做到这一点。

我对这个问题的回答是: 使用你的自定义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; } } } 

说明:

构建自己的Span可以帮助您实现许多惊人的效果,例如模糊TextView,更改TextView的背景或前景,甚至制作一些animation。 我从这篇文章中学到了很多东西。

因为要为每个字符添加间距,所以我们应该使用字符级别基础跨度,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间作为parameter passing。

构建自定义范围时,需要至少覆盖​​两个方法getSizedraw 。 在我们为整个charsequence添加间距后, getSize方法应返回最终宽度,并且在draw方法块内,您可以控制Canvas来执行所需的绘制。

那么我们如何使用这个LetterSpacingSpan? 这很容易:

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。