经过大量搜索自动调整TextView大小的最佳解决方案（根据内容，大小，最小和最大行数以及字体大小限制），我已经为它创建了一个合并的解决方案，{ {3}}
注意：我没有使用其他解决方案，因为它们不能很好地工作，每个都有自己的问题（不支持某些内容，文本超出TextView，文本被截断，... 。）。
它的演示有效：
在某些情况下，一行的最后一个字符换行到下一行，如下所示：
https://raw.githubusercontent.com/AndroidDeveloperLB/AutoFitTextView/master/animationPreview.gif
绿色是TextView的边界，红色是它的外部。
基本上，考虑到TextView的大小，其最小和最大字体大小以及最小和最大行数以及应该在其中的内容（文本），它会找到（使用二进制搜索）什么字体大小应该适合TextView的边界。
代码在Github中已经可用了，但这里只是以防万一：
public class AutoResizeTextView extends AppCompatTextView {
private static final int NO_LINE_LIMIT = -1;
private final RectF _availableSpaceRect = new RectF();
private final SizeTester _sizeTester;
private float _maxTextSize, _spacingMult = 1.0f, _spacingAdd = 0.0f, _minTextSize;
private int _widthLimit, _maxLines;
private boolean _initialized = false;
private TextPaint _paint;
private interface SizeTester {
/**
* @param suggestedSize Size of text to be tested
* @param availableSpace available space in which text must fit
* @return an integer < 0 if after applying {@code suggestedSize} to
* text, it takes less space than {@code availableSpace}, > 0
* otherwise
*/
int onTestSize(int suggestedSize, RectF availableSpace);
}
public AutoResizeTextView(final Context context) {
this(context, null, android.R.attr.textViewStyle);
}
public AutoResizeTextView(final Context context, final AttributeSet attrs) {
this(context, attrs, android.R.attr.textViewStyle);
}
public AutoResizeTextView(final Context context, final AttributeSet attrs, final int defStyle) {
super(context, attrs, defStyle);
// using the minimal recommended font size
_minTextSize = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, 12, getResources().getDisplayMetrics());
_maxTextSize = getTextSize();
_paint = new TextPaint(getPaint());
if (_maxLines == 0)
// no value was assigned during construction
_maxLines = NO_LINE_LIMIT;
// prepare size tester:
_sizeTester = new SizeTester() {
final RectF textRect = new RectF();
@TargetApi(Build.VERSION_CODES.JELLY_BEAN)
@Override
public int onTestSize(final int suggestedSize, final RectF availableSPace) {
_paint.setTextSize(suggestedSize);
final TransformationMethod transformationMethod = getTransformationMethod();
final String text;
if (transformationMethod != null)
text = transformationMethod.getTransformation(getText(), AutoResizeTextView.this).toString();
else
text = getText().toString();
final boolean singleLine = getMaxLines() == 1;
if (singleLine) {
textRect.bottom = _paint.getFontSpacing();
textRect.right = _paint.measureText(text);
} else {
final StaticLayout layout = new StaticLayout(text, _paint, _widthLimit, Alignment.ALIGN_NORMAL, _spacingMult, _spacingAdd, true);
// return early if we have more lines
if (getMaxLines() != NO_LINE_LIMIT && layout.getLineCount() > getMaxLines())
return 1;
textRect.bottom = layout.getHeight();
int maxWidth = -1;
for (int i = 0; i < layout.getLineCount(); i++)
if (maxWidth < layout.getLineRight(i) - layout.getLineLeft(i))
maxWidth = (int) layout.getLineRight(i) - (int) layout.getLineLeft(i);
textRect.right = maxWidth;
}
textRect.offsetTo(0, 0);
if (availableSPace.contains(textRect))
// may be too small, don't worry we will find the best match
return -1;
// else, too big
return 1;
}
};
_initialized = true;
}
@Override
public void setAllCaps(boolean allCaps) {
super.setAllCaps(allCaps);
adjustTextSize();
}
@Override
public void setTypeface(final Typeface tf) {
super.setTypeface(tf);
adjustTextSize();
}
@Override
public void setTextSize(final float size) {
_maxTextSize = size;
adjustTextSize();
}
@Override
public void setMaxLines(final int maxlines) {
super.setMaxLines(maxlines);
_maxLines = maxlines;
adjustTextSize();
}
@Override
public int getMaxLines() {
return _maxLines;
}
@Override
public void setSingleLine() {
super.setSingleLine();
_maxLines = 1;
adjustTextSize();
}
@Override
public void setSingleLine(final boolean singleLine) {
super.setSingleLine(singleLine);
if (singleLine)
_maxLines = 1;
else _maxLines = NO_LINE_LIMIT;
adjustTextSize();
}
@Override
public void setLines(final int lines) {
super.setLines(lines);
_maxLines = lines;
adjustTextSize();
}
@Override
public void setTextSize(final int unit, final float size) {
final Context c = getContext();
Resources r;
if (c == null)
r = Resources.getSystem();
else r = c.getResources();
_maxTextSize = TypedValue.applyDimension(unit, size, r.getDisplayMetrics());
adjustTextSize();
}
@Override
public void setLineSpacing(final float add, final float mult) {
super.setLineSpacing(add, mult);
_spacingMult = mult;
_spacingAdd = add;
}
/**
* Set the lower text size limit and invalidate the view
*
* @param minTextSize
*/
public void setMinTextSize(final float minTextSize) {
_minTextSize = minTextSize;
adjustTextSize();
}
private void adjustTextSize() {
// This is a workaround for truncated text issue on ListView, as shown here: https://github.com/AndroidDeveloperLB/AutoFitTextView/pull/14
// TODO think of a nicer, elegant solution.
// post(new Runnable()
// {
// @Override
// public void run()
// {
if (!_initialized)
return;
final int startSize = (int) _minTextSize;
final int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom() - getCompoundPaddingTop();
_widthLimit = getMeasuredWidth() - getCompoundPaddingLeft() - getCompoundPaddingRight();
if (_widthLimit <= 0)
return;
_paint = new TextPaint(getPaint());
_availableSpaceRect.right = _widthLimit;
_availableSpaceRect.bottom = heightLimit;
superSetTextSize(startSize);
// }
// });
}
private void superSetTextSize(int startSize) {
int textSize = binarySearch(startSize, (int) _maxTextSize, _sizeTester, _availableSpaceRect);
super.setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
}
private int binarySearch(final int start, final int end, final SizeTester sizeTester, final RectF availableSpace) {
int lastBest = start, lo = start, hi = end - 1, mid;
while (lo <= hi) {
mid = lo + hi >>> 1;
final int midValCmp = sizeTester.onTestSize(mid, availableSpace);
if (midValCmp < 0) {
lastBest = lo;
lo = mid + 1;
} else if (midValCmp > 0) {
hi = mid - 1;
lastBest = hi;
} else return mid;
}
// make sure to return last best
// this is what should always be returned
return lastBest;
}
@Override
protected void onTextChanged(final CharSequence text, final int start, final int before, final int after) {
super.onTextChanged(text, start, before, after);
adjustTextSize();
}
@Override
protected void onSizeChanged(final int width, final int height, final int oldwidth, final int oldheight) {
super.onSizeChanged(width, height, oldwidth, oldheight);
if (width != oldwidth || height != oldheight)
adjustTextSize();
}
}
为什么会发生？我该怎么做才能解决这个问题？
答案 0 :(得分：0)
我的项目中遇到过类似的问题。长时间的谷歌搜索，StackOverflow（与您的问题等）。什么都没有。
我的最终“解决方案”是BreakIterator用于单词+测量它们以检查这种情况。
更新（2018-08-10）：
static public boolean isTextFitWidth(final @Nullable String source, final @NonNull BreakIterator bi, final @NonNull TextPaint paint, final int width, final float textSize)
{
if (null == source || source.length() <= 0) {
return true;
}
TextPaint paintCopy = new TextPaint();
paintCopy.set(paint);
paintCopy.setTextSize(textSize);
bi.setText(source);
int start = bi.first();
for (int end = bi.next(); BreakIterator.DONE != end; start = end, end = bi.next()) {
int wordWidth = (int)Math.ceil(paintCopy.measureText(source, start, end));
if (wordWidth > width) {
return false;
}
}
return true;
}
static public boolean isTextFitWidth(final @NonNull TextView textView, final @NonNull BreakIterator bi, final int width, final @Nullable Float textSize)
{
final int textWidth = width - textView.getPaddingLeft() - textView.getPaddingRight();
return isTextFitWidth(textView.getText().toString(), bi, textView.getPaint(), textWidth,
null != textSize ? textSize : textView.getTextSize());
}
答案 1 :(得分：0)