如何在Android TextView中调整文字字距?

有没有一种方法来调整Android TextView字符间距? 我相信这通常被称为“kerning”。

我知道的android:textScaleX属性,但压缩字符与间距。

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AFAIK,你不能在TextView调整字距。 如果使用2DgraphicsAPI在Canvas上绘制文本,则可以调整字距。

我构build了一个扩展TextView的自定义类,并添加了一个“setSpacing”方法。 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,而SpannedString更改空格的TextScaleX,允许正负间距。

希望能帮助别人^^

 /** * 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来将字距应用于任何string(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build一个自定义字体,其中字形提前被改变。

这是我的解决scheme,它增加了每个字符之间的统一间距(以像素为单位)。 这个范围假定所有的文本都在一行中。 这基本上实现@commonsWarebuild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parsing它并更改每个单词的字符间距

这个答案对于那些想在Canvas上绘制文本并使用drawText(这不是TextView中的文本)有帮助。

由于棒棒糖,setLetterSpacing方法在Paint上可用。 如果SDK是LOLLIPOP,则使用setLetterSpacing。 否则,会调用一个类似于上面的@ dgmltn的build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; } 

有一个@Pedro Barros答案的小编辑。 如果你使用SpannableString来设置它,这是很有用的,例如,如果你想对某些字符做不同的颜色:

 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,但通过定义什么间距应在像素。

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开发者的初学者,如果这不好,请随时告诉我。

多一个解决scheme。

 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> 

要设置空间使用代码,如下所示:

 textView.setText(getSpacedSpannable(context, textView.getText().toString(), <Your spacing DP>), TextView.BufferType.SPANNABLE);