我正在寻找一种最佳的方法来调整包装文本在一个TextView，使它将适合它的getHeight和getWidth界限。我不是简单地寻找一种方法来包装文本-我想确保它既包装，又足够小，完全适合在屏幕上。
我在StackOverflow上看到了一些需要自动调整大小的情况，但它们要么是非常特殊的情况下的hack解决方案，没有解决方案，或涉及重新绘制TextView递归直到它足够小(这是内存紧张，迫使用户观看文本收缩一步一步与每次递归)。
但我相信有人已经找到了一个很好的解决方案，它不涉及我正在做的事情:编写几个繁重的例程来解析和测量文本，调整文本的大小，然后重复，直到找到一个合适的小尺寸。
TextView使用什么例程来包装文本?难道这些不能用来预测文本是否足够小吗?
是否有一个最佳实践的方法来自动调整TextView的大小，以适应，包装，在它的getHeight和getWidth边界?
当前回答
我的方法是:
public void changeTextSize(int initialSize, TextView tv) {
DisplayMetrics displayMetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displayMetrics);
double width = displayMetrics.widthPixels / displayMetrics.xdpi;
double height = displayMetrics.heightPixels / displayMetrics.ydpi;
Log.i("LOG", "The width of the tested emulator is: " + width);
Log.i("LOG", "The height of the tested emulator is: " + height);
double scale = Math.min(width / 2.25, height / 4.0); //See the logcat >>> width = 2.25 and heigt = 4.0
tv.setTextSize(TypedValue.COMPLEX_UNIT_SP, (int) (initialSize * scale));
}
例如:
changeTextSize(16, findViewById(R.id.myTextView));
changeTextSize(12, findViewById(R.id.myEditText));
其他回答
警告，Android蜂巢和冰淇淋三明治有bug
android版本:3.1 - 4.04有一个错误，setTextSize()内部的TextView只工作第一次(第一次调用)。
Bug描述如下:http://code.google.com/p/android/issues/detail?id=22493 http://code.google.com/p/android/issues/detail?id=17343#c9
解决方法是添加新的行字符文本分配给TextView之前改变大小:
final String DOUBLE_BYTE_SPACE = "\u3000";
textView.append(DOUBLE_BYTE_SPACE);
我在我的代码中使用它如下:
final String DOUBLE_BYTE_SPACE = "\u3000";
AutoResizeTextView textView = (AutoResizeTextView) view.findViewById(R.id.aTextView);
String fixString = "";
if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.HONEYCOMB_MR1
&& android.os.Build.VERSION.SDK_INT <= android.os.Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
fixString = DOUBLE_BYTE_SPACE;
}
textView.setText(fixString + "The text" + fixString);
我将这个“\u3000”字符添加到文本的左侧和右侧，以保持文本居中。如果你把它对齐到左边，那么只追加到右边。当然，它也可以嵌入到AutoResizeTextView小部件中，但我希望将修复代码保留在外部。
实际上解决方案是在谷歌的DialogTitle类…虽然它不如公认的方法有效，但它更简单，也更容易适应。
public class SingleLineTextView extends TextView {
public SingleLineTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
setSingleLine();
setEllipsize(TruncateAt.END);
}
public SingleLineTextView(Context context, AttributeSet attrs) {
super(context, attrs);
setSingleLine();
setEllipsize(TruncateAt.END);
}
public SingleLineTextView(Context context) {
super(context);
setSingleLine();
setEllipsize(TruncateAt.END);
}
@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
final Layout layout = getLayout();
if (layout != null) {
final int lineCount = layout.getLineCount();
if (lineCount > 0) {
final int ellipsisCount = layout.getEllipsisCount(lineCount - 1);
if (ellipsisCount > 0) {
final float textSize = getTextSize();
// textSize is already expressed in pixels
setTextSize(TypedValue.COMPLEX_UNIT_PX, (textSize - 1));
super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}
}
}
}
}
我需要调整文本的大小，以完美地适应视图边界。Chase的解决方案只是减小文本大小，如果有足够的空间，这个方案也会扩大文本。
为了使所有的快速和精确，我使用了平分方法而不是迭代while，正如你可以在resizeText()方法中看到的那样。这就是为什么你也有一个MAX_TEXT_SIZE选项。我还附上了onoelle的建议。
Android 4.4测试
/**
* DO WHAT YOU WANT TO PUBLIC LICENSE
* Version 2, December 2004
*
* Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
*
* Everyone is permitted to copy and distribute verbatim or modified
* copies of this license document, and changing it is allowed as long
* as the name is changed.
*
* DO WHAT YOU WANT TO PUBLIC LICENSE
* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
*
* 0. You just DO WHAT YOU WANT TO.
*/
import android.content.Context;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
/**
* Text view that auto adjusts text size to fit within the view.
* If the text size equals the minimum text size and still does not
* fit, append with an ellipsis.
*
* @author Chase Colburn
* @since Apr 4, 2011
*/
public class AutoResizeTextView extends TextView {
// Minimum text size for this text view
public static final float MIN_TEXT_SIZE = 26;
// Maximum text size for this text view
public static final float MAX_TEXT_SIZE = 128;
private static final int BISECTION_LOOP_WATCH_DOG = 30;
// Interface for resize notifications
public interface OnTextResizeListener {
public void onTextResize(TextView textView, float oldSize, float newSize);
}
// Our ellipse string
private static final String mEllipsis = "...";
// Registered resize listener
private OnTextResizeListener mTextResizeListener;
// Flag for text and/or size changes to force a resize
private boolean mNeedsResize = false;
// Text size that is set from code. This acts as a starting point for resizing
private float mTextSize;
// Temporary upper bounds on the starting text size
private float mMaxTextSize = MAX_TEXT_SIZE;
// Lower bounds for text size
private float mMinTextSize = MIN_TEXT_SIZE;
// Text view line spacing multiplier
private float mSpacingMult = 1.0f;
// Text view additional line spacing
private float mSpacingAdd = 0.0f;
// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;
// Default constructor override
public AutoResizeTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public AutoResizeTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTextSize = getTextSize();
}
/**
* When text changes, set the force resize flag to true and reset the text size.
*/
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
mNeedsResize = true;
// Since this view may be reused, it is good to reset the text size
resetTextSize();
}
/**
* If the text view size changed, set the force resize flag to true
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
if (w != oldw || h != oldh) {
mNeedsResize = true;
}
}
/**
* Register listener to receive resize notifications
* @param listener
*/
public void setOnResizeListener(OnTextResizeListener listener) {
mTextResizeListener = listener;
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(float size) {
super.setTextSize(size);
mTextSize = getTextSize();
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(int unit, float size) {
super.setTextSize(unit, size);
mTextSize = getTextSize();
}
/**
* Override the set line spacing to update our internal reference values
*/
@Override
public void setLineSpacing(float add, float mult) {
super.setLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
/**
* Set the upper text size limit and invalidate the view
* @param maxTextSize
*/
public void setMaxTextSize(float maxTextSize) {
mMaxTextSize = maxTextSize;
requestLayout();
invalidate();
}
/**
* Return upper text size limit
* @return
*/
public float getMaxTextSize() {
return mMaxTextSize;
}
/**
* Set the lower text size limit and invalidate the view
* @param minTextSize
*/
public void setMinTextSize(float minTextSize) {
mMinTextSize = minTextSize;
requestLayout();
invalidate();
}
/**
* Return lower text size limit
* @return
*/
public float getMinTextSize() {
return mMinTextSize;
}
/**
* Set flag to add ellipsis to text that overflows at the smallest text size
* @param addEllipsis
*/
public void setAddEllipsis(boolean addEllipsis) {
mAddEllipsis = addEllipsis;
}
/**
* Return flag to add ellipsis to text that overflows at the smallest text size
* @return
*/
public boolean getAddEllipsis() {
return mAddEllipsis;
}
/**
* Reset the text to the original size
*/
public void resetTextSize() {
if(mTextSize > 0) {
super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
//mMaxTextSize = mTextSize;
}
}
/**
* Resize text after measuring
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
if(changed || mNeedsResize) {
int widthLimit = (right - left) - getCompoundPaddingLeft() - getCompoundPaddingRight();
int heightLimit = (bottom - top) - getCompoundPaddingBottom() - getCompoundPaddingTop();
resizeText(widthLimit, heightLimit);
}
super.onLayout(changed, left, top, right, bottom);
}
/**
* Resize the text size with default width and height
*/
public void resizeText() {
int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
resizeText(widthLimit, heightLimit);
}
/**
* Resize the text size with specified width and height
* @param width
* @param height
*/
public void resizeText(int width, int height) {
CharSequence text = getText();
// Do not resize if the view does not have dimensions or there is no text
if(text == null || text.length() == 0 || height <= 0 || width <= 0 || mTextSize == 0) {
return;
}
// Get the text view's paint object
TextPaint textPaint = getPaint();
// Store the current text size
float oldTextSize = textPaint.getTextSize();
// Bisection method: fast & precise
float lower = mMinTextSize;
float upper = mMaxTextSize;
int loop_counter=1;
float targetTextSize = (lower+upper)/2;
int textHeight = getTextHeight(text, textPaint, width, targetTextSize);
while(loop_counter < BISECTION_LOOP_WATCH_DOG && upper - lower > 1) {
targetTextSize = (lower+upper)/2;
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
if(textHeight > height)
upper = targetTextSize;
else
lower = targetTextSize;
loop_counter++;
}
targetTextSize = lower;
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
// If we had reached our minimum text size and still don't fit, append an ellipsis
if(mAddEllipsis && targetTextSize == mMinTextSize && textHeight > height) {
// Draw using a static layout
// modified: use a copy of TextPaint for measuring
TextPaint paintCopy = new TextPaint(textPaint);
paintCopy.setTextSize(targetTextSize);
StaticLayout layout = new StaticLayout(text, paintCopy, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
// Check that we have a least one line of rendered text
if(layout.getLineCount() > 0) {
// Since the line at the specific vertical position would be cut off,
// we must trim up to the previous line
int lastLine = layout.getLineForVertical(height) - 1;
// If the text would not even fit on a single line, clear it
if(lastLine < 0) {
setText("");
}
// Otherwise, trim to the previous line and add an ellipsis
else {
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
float lineWidth = layout.getLineWidth(lastLine);
float ellipseWidth = paintCopy.measureText(mEllipsis);
// Trim characters off until we have enough room to draw the ellipsis
while(width < lineWidth + ellipseWidth) {
lineWidth = paintCopy.measureText(text.subSequence(start, --end + 1).toString());
}
setText(text.subSequence(0, end) + mEllipsis);
}
}
}
// Some devices try to auto adjust line spacing, so force default line spacing
// and invalidate the layout as a side effect
setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize);
setLineSpacing(mSpacingAdd, mSpacingMult);
// Notify the listener if registered
if(mTextResizeListener != null) {
mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
}
// Reset force resize flag
mNeedsResize = false;
}
// Set the text size of the text paint object and use a static layout to render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint, int width, float textSize) {
// modified: make a copy of the original TextPaint object for measuring
// (apparently the object gets modified while measuring, see also the
// docs for TextView.getPaint() (which states to access it read-only)
TextPaint paint = new TextPaint(originalPaint);
// Update the text paint object
paint.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paint, width, Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
}
我结合了上面的一些建议，用二分法制作了一个上下伸缩的图。它还在宽度范围内缩放。
/**
* DO WHAT YOU WANT TO PUBLIC LICENSE
* Version 2, December 2004
*
* Copyright (C) 2004 Sam Hocevar <sam@hocevar.net>
*
* Everyone is permitted to copy and distribute verbatim or modified
* copies of this license document, and changing it is allowed as long
* as the name is changed.
*
* DO WHAT YOU WANT TO PUBLIC LICENSE
* TERMS AND CONDITIONS FOR COPYING, DISTRIBUTION AND MODIFICATION
*
* 0. You just DO WHAT YOU WANT TO.
*/
import android.content.Context;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.TypedValue;
import android.widget.TextView;
/**
* Text view that auto adjusts text size to fit within the view. If the text
* size equals the minimum text size and still does not fit, append with an
* ellipsis.
*
* @author Chase Colburn
* @since Apr 4, 2011
*/
public class AutoResizeTextView extends TextView {
// Minimum text size for this text view
public static final float MIN_TEXT_SIZE = 10;
// Minimum text size for this text view
public static final float MAX_TEXT_SIZE = 128;
private static final int BISECTION_LOOP_WATCH_DOG = 30;
// Interface for resize notifications
public interface OnTextResizeListener {
public void onTextResize(TextView textView, float oldSize, float newSize);
}
// Our ellipse string
private static final String mEllipsis = "...";
// Registered resize listener
private OnTextResizeListener mTextResizeListener;
// Flag for text and/or size changes to force a resize
private boolean mNeedsResize = false;
// Text size that is set from code. This acts as a starting point for
// resizing
private float mTextSize;
// Temporary upper bounds on the starting text size
private float mMaxTextSize = MAX_TEXT_SIZE;
// Lower bounds for text size
private float mMinTextSize = MIN_TEXT_SIZE;
// Text view line spacing multiplier
private float mSpacingMult = 1.0f;
// Text view additional line spacing
private float mSpacingAdd = 0.0f;
// Add ellipsis to text that overflows at the smallest text size
private boolean mAddEllipsis = true;
// Default constructor override
public AutoResizeTextView(Context context) {
this(context, null);
}
// Default constructor when inflating from XML file
public AutoResizeTextView(Context context, AttributeSet attrs) {
this(context, attrs, 0);
}
// Default constructor override
public AutoResizeTextView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
mTextSize = getTextSize();
}
/**
* When text changes, set the force resize flag to true and reset the text
* size.
*/
@Override
protected void onTextChanged(final CharSequence text, final int start,
final int before, final int after) {
mNeedsResize = true;
// Since this view may be reused, it is good to reset the text size
resetTextSize();
}
/**
* If the text view size changed, set the force resize flag to true
*/
@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
if (w != oldw || h != oldh) {
mNeedsResize = true;
}
}
/**
* Register listener to receive resize notifications
*
* @param listener
*/
public void setOnResizeListener(OnTextResizeListener listener) {
mTextResizeListener = listener;
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(float size) {
super.setTextSize(size);
mTextSize = getTextSize();
}
/**
* Override the set text size to update our internal reference values
*/
@Override
public void setTextSize(int unit, float size) {
super.setTextSize(unit, size);
mTextSize = getTextSize();
}
/**
* Override the set line spacing to update our internal reference values
*/
@Override
public void setLineSpacing(float add, float mult) {
super.setLineSpacing(add, mult);
mSpacingMult = mult;
mSpacingAdd = add;
}
/**
* Set the upper text size limit and invalidate the view
*
* @param maxTextSize
*/
public void setMaxTextSize(float maxTextSize) {
mMaxTextSize = maxTextSize;
requestLayout();
invalidate();
}
/**
* Return upper text size limit
*
* @return
*/
public float getMaxTextSize() {
return mMaxTextSize;
}
/**
* Set the lower text size limit and invalidate the view
*
* @param minTextSize
*/
public void setMinTextSize(float minTextSize) {
mMinTextSize = minTextSize;
requestLayout();
invalidate();
}
/**
* Return lower text size limit
*
* @return
*/
public float getMinTextSize() {
return mMinTextSize;
}
/**
* Set flag to add ellipsis to text that overflows at the smallest text size
*
* @param addEllipsis
*/
public void setAddEllipsis(boolean addEllipsis) {
mAddEllipsis = addEllipsis;
}
/**
* Return flag to add ellipsis to text that overflows at the smallest text
* size
*
* @return
*/
public boolean getAddEllipsis() {
return mAddEllipsis;
}
/**
* Reset the text to the original size
*/
public void resetTextSize() {
if (mTextSize > 0) {
super.setTextSize(TypedValue.COMPLEX_UNIT_PX, mTextSize);
// mMaxTextSize = mTextSize;
}
}
/**
* Resize text after measuring
*/
@Override
protected void onLayout(boolean changed, int left, int top, int right,
int bottom) {
if (changed || mNeedsResize) {
int widthLimit = (right - left) - getCompoundPaddingLeft()
- getCompoundPaddingRight();
int heightLimit = (bottom - top) - getCompoundPaddingBottom()
- getCompoundPaddingTop();
resizeText(widthLimit, heightLimit);
}
super.onLayout(changed, left, top, right, bottom);
}
/**
* Resize the text size with default width and height
*/
public void resizeText() {
// Height and width with a padding as a percentage of height
int heightLimit = getHeight() - getPaddingBottom() - getPaddingTop();
int widthLimit = getWidth() - getPaddingLeft() - getPaddingRight();
resizeText(widthLimit, heightLimit);
}
/**
* Resize the text size with specified width and height
*
* @param width
* @param height
*/
public void resizeText(int width, int height) {
CharSequence text = getText();
// Do not resize if the view does not have dimensions or there is no
// text
if (text == null || text.length() == 0 || height <= 0 || width <= 0
|| mTextSize == 0) {
return;
}
// Get the text view's paint object
TextPaint textPaint = getPaint();
// Store the current text size
float oldTextSize = textPaint.getTextSize();
// Bisection method: fast & precise
float lower = mMinTextSize;
float upper = mMaxTextSize;
int loop_counter = 1;
float targetTextSize = (lower + upper) / 2;
int textHeight = getTextHeight(text, textPaint, width, targetTextSize);
int textWidth = getTextWidth(text, textPaint, width, targetTextSize);
while (loop_counter < BISECTION_LOOP_WATCH_DOG && upper - lower > 1) {
targetTextSize = (lower + upper) / 2;
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
textWidth = getTextWidth(text, textPaint, width, targetTextSize);
if (textHeight > (height) || textWidth > (width))
upper = targetTextSize;
else
lower = targetTextSize;
loop_counter++;
}
targetTextSize = lower;
textHeight = getTextHeight(text, textPaint, width, targetTextSize);
// If we had reached our minimum text size and still don't fit, append
// an ellipsis
if (mAddEllipsis && targetTextSize == mMinTextSize
&& textHeight > height) {
// Draw using a static layout
// modified: use a copy of TextPaint for measuring
TextPaint paintCopy = new TextPaint(textPaint);
paintCopy.setTextSize(targetTextSize);
StaticLayout layout = new StaticLayout(text, paintCopy, width,
Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, false);
// Check that we have a least one line of rendered text
if (layout.getLineCount() > 0) {
// Since the line at the specific vertical position would be cut
// off,
// we must trim up to the previous line
int lastLine = layout.getLineForVertical(height) - 1;
// If the text would not even fit on a single line, clear it
if (lastLine < 0) {
setText("");
}
// Otherwise, trim to the previous line and add an ellipsis
else {
int start = layout.getLineStart(lastLine);
int end = layout.getLineEnd(lastLine);
float lineWidth = layout.getLineWidth(lastLine);
float ellipseWidth = paintCopy.measureText(mEllipsis);
// Trim characters off until we have enough room to draw the
// ellipsis
while (width < lineWidth + ellipseWidth) {
lineWidth = paintCopy.measureText(text.subSequence(
start, --end + 1).toString());
}
setText(text.subSequence(0, end) + mEllipsis);
}
}
}
// Some devices try to auto adjust line spacing, so force default line
// spacing
// and invalidate the layout as a side effect
setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize);
setLineSpacing(mSpacingAdd, mSpacingMult);
// Notify the listener if registered
if (mTextResizeListener != null) {
mTextResizeListener.onTextResize(this, oldTextSize, targetTextSize);
}
// Reset force resize flag
mNeedsResize = false;
}
// Set the text size of the text paint object and use a static layout to
// render text off screen before measuring
private int getTextHeight(CharSequence source, TextPaint originalPaint,
int width, float textSize) {
// modified: make a copy of the original TextPaint object for measuring
// (apparently the object gets modified while measuring, see also the
// docs for TextView.getPaint() (which states to access it read-only)
TextPaint paint = new TextPaint(originalPaint);
// Update the text paint object
paint.setTextSize(textSize);
// Measure using a static layout
StaticLayout layout = new StaticLayout(source, paint, width,
Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return layout.getHeight();
}
// Set the text size of the text paint object and use a static layout to
// render text off screen before measuring
private int getTextWidth(CharSequence source, TextPaint originalPaint,
int width, float textSize) {
// Update the text paint object
TextPaint paint = new TextPaint(originalPaint);
// Draw using a static layout
paint.setTextSize(textSize);
StaticLayout layout = new StaticLayout(source, paint, width,
Alignment.ALIGN_NORMAL, mSpacingMult, mSpacingAdd, true);
return (int) layout.getLineWidth(0);
}
}
Android 4.x的一个变通方案:
我找到了AutoResizeTextView，它在我的Android 2.1模拟器上工作得很好。我非常喜欢它。但不幸的是，它在我自己的4.0.4手机和4.1模拟器上失败了。经过尝试，我发现它可以通过在xml中的AutoResizeTextView类中添加以下属性轻松解决:
android：ellipsize=“none” android：singleLine=“true”
有了上面的两行，现在AutoResizeTextView在我的2.1和4.1模拟器和我自己的4.0.4手机上完美地工作。
希望这对你有所帮助。: -)
