我们需要为自动适应的TextView来给它的界限的字体多次。

Many times we need to auto-fit the font of the TextView to the boundaries given to it.

可悲的是，尽管有许多主题帖子（和建议的解决方案）谈论这个问题（例如here ，here和这里），他们没有实际工作。

Sadly, even though there are many threads and posts (and suggested solutions) talking about this problem (example here , here and here), none of them actually work well.

这就是为什么，我决定测试他们每个人，直到我找到了真正的交易。

That's why, I've decided to test each of them till I find the real deal.

我觉得从这样一个TextView的要求应该是：

I think that the requirements from such a textView should be:

如果允许使用任何字体，字体，样式和字符集。

Should allow using any font,typeface,style and set of characters .

应该处理宽度和高度

没有截断，除非文本不适合，因为的限制，我们已经 给它（例如：太长的文字，太小可用大小）。但是，我们可以为水平/垂直滚动条要求，如果我们希望，只是这些情况。

No truncation unless text cannot fit because of the limitation, we've given to it (example: too long text, too small available size). However, we could request for horizontal/vertical scrollbar if we wish, just for those cases.

应该让多行或单行。如果多行的，允许最大和放大器;分线

Should allow multi-line or single-line. In case of multi-line, allow max&min lines.

不应该在计算速度慢。使用寻找最佳尺寸的循环？至少进行优化，并且不增加每一次你的取样1。

Should not be slow in computation. Using a loop for finding the best size? At least optimize it and don't increment your sampling by 1 each time.

在的情况下的多线的，应该允许preFER调整大小或使用更多的行，和/或允许通过使用\ n字符来选择线路自己

In case of multi-line, should allow to prefer resizing or using more lines , and/or allow to choose the lines ourselves by using the "\n" character .

我试过这么多的样本（包括那些环节，我已经写了），我也试着修改它们处理的情况下，我谈到过，但没有真正发挥作用。

What I've tried

I've tried so many samples (including those of the links, I've written about), and I've also tried to modify them to handle the cases, I've talked about, but none really work.

我做了一个示例项目，让我直观地看到，如果TextView的正确自动适应。

I've made a sample project that allows me to visually see if the TextView auto-fits correctly.

目前，我的样本项目只是随机的文字（英文字母和数字）和TextView的大小，让它留在单行线，但即使这样不会对任何我有样品的正常工作试过了。

Currently, my sample project only randomize the text (the English alphabet plus digits) and the size of the textView, and let it stay with single line, but even this doesn't work well on any of the samples I've tried.

这里的code（也可这里）：

Here's the code (also available here) :

RES /布局/ activity_main.xml

res/layout/activity_main.xml

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
  xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"
  android:layout_height="match_parent" tools:context=".MainActivity">
  <Button android:id="@+id/button1" android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true" android:text="Button" />
  <FrameLayout android:layout_width="match_parent"
    android:layout_height="wrap_content" android:layout_above="@+id/button1"
    android:layout_alignParentLeft="true" android:background="#ffff0000"
    android:layout_alignParentRight="true" android:id="@+id/container"
    android:layout_alignParentTop="true" />

</RelativeLayout>

SRC /.../ MainActivity.java

src/.../MainActivity.java

public class MainActivity extends Activity
  {
  private final Random        _random            =new Random();
  private static final String ALLOWED_CHARACTERS ="qwertyuiopasdfghjklzxcvbnmQWERTYUIOPASDFGHJKLZXCVBNM1234567890";

  @Override
  protected void onCreate(final Bundle savedInstanceState)
    {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final ViewGroup container=(ViewGroup)findViewById(R.id.container);
    findViewById(R.id.button1).setOnClickListener(new OnClickListener()
      {
        @Override
        public void onClick(final View v)
          {
          container.removeAllViews();
          final int maxWidth=container.getWidth();
          final int maxHeight=container.getHeight();
          final FontFitTextView fontFitTextView=new FontFitTextView(MainActivity.this);
          final int width=_random.nextInt(maxWidth)+1;
          final int height=_random.nextInt(maxHeight)+1;
          fontFitTextView.setLayoutParams(new LayoutParams(width,height));
          fontFitTextView.setSingleLine();
          fontFitTextView.setBackgroundColor(0xff00ff00);
          final String text=getRandomText();
          fontFitTextView.setText(text);
          container.addView(fontFitTextView);
          Log.d("DEBUG","width:"+width+" height:"+height+" text:"+text);
          }
      });
    }

  private String getRandomText()
    {
    final int textLength=_random.nextInt(20)+1;
    final StringBuilder builder=new StringBuilder();
    for(int i=0;i<textLength;++i)
      builder.append(ALLOWED_CHARACTERS.charAt(_random.nextInt(ALLOWED_CHARACTERS.length())));
    return builder.toString();
    }
  }

问题

有谁知道这个常见问题的解决方案是实际工作的？

The question

Does anybody know of a solution for this common problem that actually work?

即使是一个解决方案，有什么我已经写少得多的功能，例如，一个具有文本行只是一个常数，并调整其字体根据其大小，但永远不会有奇怪的毛刺和具有相比，它的可用空间的文字过于大/小。

Even a solution that has much less features that what I've written about, for example one that has just a constant number of lines of text, and adjusts its font according to its size , yet never have weird glitches and having the text get too large/small compared to its available space.

编辑：因为这是一个非常重要的TextView，我决定发布一个图书馆，让每个人都可以轻松地使用它，并作出贡献，的 此处 。

since this is such an important TextView, I've decided to publish a library, so that everyone could easily use it, and contribute to it, here.

推荐答案

更新：由于MartinH的简单修复的这里，这code也需要照顾安卓drawableLeft ，安卓drawableRight ， 安卓drawableTop 和安卓drawableBottom 标签

UPDATE: Thanks to MartinH's simple fix here, this code also takes care of android:drawableLeft, android:drawableRight, android:drawableTop and android:drawableBottom tags.

在这里我的回答应该让你快乐Auto规模的TextView文本界内适合

My answer here should make you happy Auto Scale TextView Text to Fit within Bounds

我已经修改了你的测试案例：

I have modified your test case:

@Override
protected void onCreate(final Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final ViewGroup container = (ViewGroup) findViewById(R.id.container);
    findViewById(R.id.button1).setOnClickListener(new OnClickListener() {
        @Override
        public void onClick(final View v) {
            container.removeAllViews();
            final int maxWidth = container.getWidth();
            final int maxHeight = container.getHeight();
            final AutoResizeTextView fontFitTextView = new AutoResizeTextView(MainActivity.this);
            final int width = _random.nextInt(maxWidth) + 1;
            final int height = _random.nextInt(maxHeight) + 1;
            fontFitTextView.setLayoutParams(new FrameLayout.LayoutParams(
                    width, height));
            int maxLines = _random.nextInt(4) + 1;
            fontFitTextView.setMaxLines(maxLines);
            fontFitTextView.setTextSize(500);// max size
            fontFitTextView.enableSizeCache(false);
            fontFitTextView.setBackgroundColor(0xff00ff00);
            final String text = getRandomText();
            fontFitTextView.setText(text);
            container.addView(fontFitTextView);
            Log.d("DEBUG", "width:" + width + " height:" + height
                    + " text:" + text + " maxLines:" + maxLines);
        }
    });
}

更新：

我在这里张贴code，每 Android开发的的要求：

I am posting code here at per android developer's request:

最终效果：

布局示例文件：

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="16dp" >

<com.vj.widgets.AutoResizeTextView
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:ellipsize="none"
    android:maxLines="2"
    android:text="Auto Resized Text, max 2 lines"
    android:textSize="100sp" /> <!-- maximum size -->

<com.vj.widgets.AutoResizeTextView
    android:layout_width="match_parent"
    android:layout_height="100dp"
    android:ellipsize="none"
    android:gravity="center"
    android:maxLines="1"
    android:text="Auto Resized Text, max 1 line"
    android:textSize="100sp" /> <!-- maximum size -->

<com.vj.widgets.AutoResizeTextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="Auto Resized Text"
    android:textSize="500sp" /> <!-- maximum size -->

</LinearLayout>

和Java code：

import android.annotation.TargetApi;
import android.content.Context;
import android.content.res.Resources;
import android.graphics.RectF;
import android.os.Build;
import android.text.Layout.Alignment;
import android.text.StaticLayout;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.util.SparseIntArray;
import android.util.TypedValue;
import android.widget.TextView;

public class AutoResizeTextView extends TextView {
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
     */
    public int onTestSize(int suggestedSize, RectF availableSpace);
}

private RectF mTextRect = new RectF();

private RectF mAvailableSpaceRect;

private SparseIntArray mTextCachedSizes;

private TextPaint mPaint;

private float mMaxTextSize;

private float mSpacingMult = 1.0f;

private float mSpacingAdd = 0.0f;

private float mMinTextSize = 20;

private int mWidthLimit;

private static final int NO_LINE_LIMIT = -1;
private int mMaxLines;

private boolean mEnableSizeCache = true;
private boolean mInitiallized;

public AutoResizeTextView(Context context) {
    super(context);
    initialize();
}

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

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

private void initialize() {
    mPaint = new TextPaint(getPaint());
    mMaxTextSize = getTextSize();
    mAvailableSpaceRect = new RectF();
    mTextCachedSizes = new SparseIntArray();
    if (mMaxLines == 0) {
        // no value was assigned during construction
        mMaxLines = NO_LINE_LIMIT;
    }
    mInitiallized = true;
}

@Override
public void setText(final CharSequence text, BufferType type) {
    super.setText(text, type);
    adjustTextSize(text.toString());
}

@Override
public void setTextSize(float size) {
    mMaxTextSize = size;
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

@Override
public void setMaxLines(int maxlines) {
    super.setMaxLines(maxlines);
    mMaxLines = maxlines;
    reAdjust();
}

public int getMaxLines() {
    return mMaxLines;
}

@Override
public void setSingleLine() {
    super.setSingleLine();
    mMaxLines = 1;
    reAdjust();
}

@Override
public void setSingleLine(boolean singleLine) {
    super.setSingleLine(singleLine);
    if (singleLine) {
        mMaxLines = 1;
    } else {
        mMaxLines = NO_LINE_LIMIT;
    }
    reAdjust();
}

@Override
public void setLines(int lines) {
    super.setLines(lines);
    mMaxLines = lines;
    reAdjust();
}

@Override
public void setTextSize(int unit, float size) {
    Context c = getContext();
    Resources r;

    if (c == null)
        r = Resources.getSystem();
    else
        r = c.getResources();
    mMaxTextSize = TypedValue.applyDimension(unit, size,
            r.getDisplayMetrics());
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

@Override
public void setLineSpacing(float add, float mult) {
    super.setLineSpacing(add, mult);
    mSpacingMult = mult;
    mSpacingAdd = add;
}

/**
 * Set the lower text size limit and invalidate the view
 * 
 * @param minTextSize
 */
public void setMinTextSize(float minTextSize) {
    mMinTextSize = minTextSize;
    reAdjust();
}

private void reAdjust() {
    adjustTextSize(getText().toString());
}

private void adjustTextSize(String string) {
    if (!mInitiallized) {
        return;
    }
    int startSize = (int) mMinTextSize;
    int heightLimit = getMeasuredHeight() - getCompoundPaddingBottom()
            - getCompoundPaddingTop();
    mWidthLimit = getMeasuredWidth() - getCompoundPaddingLeft()
            - getCompoundPaddingRight();
    mAvailableSpaceRect.right = mWidthLimit;
    mAvailableSpaceRect.bottom = heightLimit;
    super.setTextSize(
            TypedValue.COMPLEX_UNIT_PX,
            efficientTextSizeSearch(startSize, (int) mMaxTextSize,
                    mSizeTester, mAvailableSpaceRect));
}

private final SizeTester mSizeTester = new SizeTester() {
    @TargetApi(Build.VERSION_CODES.JELLY_BEAN)
    @Override
    public int onTestSize(int suggestedSize, RectF availableSPace) {
        mPaint.setTextSize(suggestedSize);
        String text = getText().toString();
        boolean singleline = getMaxLines() == 1;
        if (singleline) {
            mTextRect.bottom = mPaint.getFontSpacing();
            mTextRect.right = mPaint.measureText(text);
        } else {
            StaticLayout layout = new StaticLayout(text, mPaint,
                    mWidthLimit, Alignment.ALIGN_NORMAL, mSpacingMult,
                    mSpacingAdd, true);
            // return early if we have more lines
            if (getMaxLines() != NO_LINE_LIMIT
                    && layout.getLineCount() > getMaxLines()) {
                return 1;
            }
            mTextRect.bottom = layout.getHeight();
            int maxWidth = -1;
            for (int i = 0; i < layout.getLineCount(); i++) {
                if (maxWidth < layout.getLineWidth(i)) {
                    maxWidth = (int) layout.getLineWidth(i);
                }
            }
            mTextRect.right = maxWidth;
        }

        mTextRect.offsetTo(0, 0);
        if (availableSPace.contains(mTextRect)) {
            // may be too small, don't worry we will find the best match
            return -1;
        } else {
            // too big
            return 1;
        }
    }
};

/**
 * Enables or disables size caching, enabling it will improve performance
 * where you are animating a value inside TextView. This stores the font
 * size against getText().length() Be careful though while enabling it as 0
 * takes more space than 1 on some fonts and so on.
 * 
 * @param enable
 *            enable font size caching
 */
public void enableSizeCache(boolean enable) {
    mEnableSizeCache = enable;
    mTextCachedSizes.clear();
    adjustTextSize(getText().toString());
}

private int efficientTextSizeSearch(int start, int end,
        SizeTester sizeTester, RectF availableSpace) {
    if (!mEnableSizeCache) {
        return binarySearch(start, end, sizeTester, availableSpace);
    }
    String text = getText().toString();
    int key = text == null ? 0 : text.length();
    int size = mTextCachedSizes.get(key);
    if (size != 0) {
        return size;
    }
    size = binarySearch(start, end, sizeTester, availableSpace);
    mTextCachedSizes.put(key, size);
    return size;
}

private static int binarySearch(int start, int end, SizeTester sizeTester,
        RectF availableSpace) {
    int lastBest = start;
    int lo = start;
    int hi = end - 1;
    int mid = 0;
    while (lo <= hi) {
        mid = (lo + hi) >>> 1;
        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);
    reAdjust();
}

@Override
protected void onSizeChanged(int width, int height, int oldwidth,
        int oldheight) {
    mTextCachedSizes.clear();
    super.onSizeChanged(width, height, oldwidth, oldheight);
    if (width != oldwidth || height != oldheight) {
        reAdjust();
    }
}
}

警告： 当心这解决的在Android的蜂窝（平台3.1），但。错误