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));

我希望这对你有所帮助

import android.content.Context;
import android.graphics.Rect;
import android.text.TextPaint;
import android.util.AttributeSet;
import android.widget.TextView;

/* Based on 
 * from http://stackoverflow.com/questions/2617266/how-to-adjust-text-font-size-to-fit-textview
 */
public class FontFitTextView extends TextView {

private static float MAX_TEXT_SIZE = 20;

public FontFitTextView(Context context) {
    this(context, null);
}

public FontFitTextView(Context context, AttributeSet attrs) {
    super(context, attrs);

    float size = this.getTextSize();
    if (size > MAX_TEXT_SIZE)
        setTextSize(MAX_TEXT_SIZE);
}

private void refitText(String text, int textWidth) {
    if (textWidth > 0) {
        float availableWidth = textWidth - this.getPaddingLeft()
                - this.getPaddingRight();

        TextPaint tp = getPaint();
        Rect rect = new Rect();
        tp.getTextBounds(text, 0, text.length(), rect);
        float size = rect.width();

        if (size > availableWidth)
            setTextScaleX(availableWidth / size);
    }
}

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
    int parentWidth = MeasureSpec.getSize(widthMeasureSpec);
    int parentHeight = MeasureSpec.getSize(heightMeasureSpec);
    refitText(this.getText().toString(), parentWidth);
    this.setMeasuredDimension(parentWidth, parentHeight);
}

@Override
protected void onTextChanged(final CharSequence text, final int start,
        final int before, final int after) {
    refitText(text.toString(), this.getWidth());
}

@Override
protected void onSizeChanged(int w, int h, int oldw, int oldh) {
    if (w != oldw) {
        refitText(this.getText().toString(), w);
    }
}
}

注意:我使用MAX_TEXT_SIZE在文本大小大于20的情况下，因为我不想让大字体适用于我的视图，如果这不是你的情况下，你可以简单地删除它。

我为此写了一篇博客。

我根据Kirill Grouchnikov关于在新的android market应用中使用的自定义组件的博客文章创建了一个名为ResizableButton的组件。我把src代码放在这里。

另一方面，mosabua读了我的文章，并告诉我他将开源他的实现，这比我的更快。我希望他能尽快发布:)

如果有人需要它，这里是相同的代码片段，但Xamarin.Android。

/**
 *               DO WHAT YOU WANT TO PUBLIC LICENSE
 *                    Version 1, December 2017
 * 
 * Copyright (C) 2017 Nathan Westfall
 * 
 * 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.
 */

using Android.Content;
using Android.Runtime;
using Android.Widget;
using Android.Util;
using Android.Text;

using Java.Lang;

namespace My.Text
{
    public class AutoResizeTextView : TextView
    {
        public const float MIN_TEXT_SIZE = 20;

        public interface OnTextResizeListener
        {
            void OnTextResize(TextView textView, float oldSize, float newSize);
        }

        private const string mEllipsis = "...";

        private OnTextResizeListener mTextResizeListener;

        private bool mNeedsResize = false;

        private float mTextSize;

        private float mMaxTextSize = 0;

        private float mMinTextSize = MIN_TEXT_SIZE;

        private float mSpacingMult = 1.0f;

        private float mSpacingAdd = 0.0f;

        public bool AddEllipsis { get; set; } = true;

        public AutoResizeTextView(Context context) : this(context, null) { }

        public AutoResizeTextView(Context context, IAttributeSet attrs) : this(context, attrs, 0) { }

        public AutoResizeTextView(Context context, IAttributeSet attrs, int defStyle): base(context, attrs, defStyle)
        {
            mTextSize = TextSize;
        }

        protected override void OnTextChanged(ICharSequence text, int start, int lengthBefore, int lengthAfter)
        {
            base.OnTextChanged(text, start, lengthBefore, lengthAfter);

            mNeedsResize = true;

            ResetTextSize();
        }

        protected override void OnSizeChanged(int w, int h, int oldw, int oldh)
        {
            base.OnSizeChanged(w, h, oldw, oldh);

            if (w != oldw || h != oldh)
                mNeedsResize = true;
        }

        public void SetOnResizeListener(OnTextResizeListener listener)
        {
            mTextResizeListener = listener;
        }

        public override void SetTextSize([GeneratedEnum] ComplexUnitType unit, float size)
        {
            base.SetTextSize(unit, size);

            mTextSize = TextSize;
        }

        public override void SetLineSpacing(float add, float mult)
        {
            base.SetLineSpacing(add, mult);

            mSpacingMult = mult;
            mSpacingAdd = add;
        }

        public void SetMaxTextSize(float maxTextSize)
        {
            mMaxTextSize = maxTextSize;
            RequestLayout();
            Invalidate();
        }

        public float GetMaxTextSize()
        {
            return mMaxTextSize;
        }

        public void SetMinTextSize(float minTextSize)
        {
            mMinTextSize = minTextSize;
            RequestLayout();
            Invalidate();
        }

        public float GetMinTextSize()
        {
            return mMinTextSize;
        }

        public void ResetTextSize()
        {
            if(mTextSize > 0)
            {
                base.SetTextSize(ComplexUnitType.Px, mTextSize);
                mMaxTextSize = mTextSize;
            }
        }

        protected override void OnLayout(bool changed, int left, int top, int right, int bottom)
        {
            if(changed || mNeedsResize)
            {
                int widthLimit = (right - left) - CompoundPaddingLeft - CompoundPaddingRight;
                int heightLimit = (bottom - top) - CompoundPaddingBottom - CompoundPaddingTop;
                ResizeText(widthLimit, heightLimit);
            }
            base.OnLayout(changed, left, top, right, bottom);

            base.OnLayout(changed, left, top, right, bottom);
        }

        public void ResizeText()
        {
            int heightLimit = Height - PaddingBottom - PaddingTop;
            int widthLimit = Width - PaddingLeft - PaddingRight;
            ResizeText(widthLimit, heightLimit);
        }

        public void ResizeText(int width, int height)
        {
            var text = TextFormatted;
            if (text == null || text.Length() == 0 || height <= 0 || width <= 0 || mTextSize == 0)
                return;

            if (TransformationMethod != null)
                text = TransformationMethod.GetTransformationFormatted(TextFormatted, this);

            TextPaint textPaint = Paint;

            float oldTextSize = textPaint.TextSize;
            float targetTextSize = mMaxTextSize > 0 ? System.Math.Min(mTextSize, mMaxTextSize) : mTextSize;

            int textHeight = GetTextHeight(text, textPaint, width, targetTextSize);

            while(textHeight > height && targetTextSize > mMinTextSize)
            {
                targetTextSize = System.Math.Max(targetTextSize - 2, mMinTextSize);
                textHeight = GetTextHeight(text, textPaint, width, targetTextSize);
            }

            if(AddEllipsis && targetTextSize == mMinTextSize && textHeight > height)
            {
                TextPaint paint = new TextPaint(textPaint);

                StaticLayout layout = new StaticLayout(text, paint, width, Layout.Alignment.AlignNormal, mSpacingMult, mSpacingAdd, false);
                if(layout.LineCount > 0)
                {
                    int lastLine = layout.GetLineForVertical(height) - 1;
                    if (lastLine < 0)
                        SetText("", BufferType.Normal);
                    else
                    {
                        int start = layout.GetLineStart(lastLine);
                        int end = layout.GetLineEnd(lastLine);
                        float lineWidth = layout.GetLineWidth(lastLine);
                        float ellipseWidth = textPaint.MeasureText(mEllipsis);

                        while (width < lineWidth + ellipseWidth)
                            lineWidth = textPaint.MeasureText(text.SubSequence(start, --end + 1).ToString());
                        SetText(text.SubSequence(0, end) + mEllipsis, BufferType.Normal);
                    }
                }
            }

            SetTextSize(ComplexUnitType.Px, targetTextSize);
            SetLineSpacing(mSpacingAdd, mSpacingMult);

            mTextResizeListener?.OnTextResize(this, oldTextSize, targetTextSize);

            mNeedsResize = false;
        }

        private int GetTextHeight(ICharSequence source, TextPaint paint, int width, float textSize)
        {
            TextPaint paintCopy = new TextPaint(paint);
            paintCopy.TextSize = textSize;
            StaticLayout layout = new StaticLayout(source, paintCopy, width, Layout.Alignment.AlignNormal, mSpacingMult, mSpacingAdd, false);
            return layout.Height;
        }
    }
}

我从Chase的解决方案开始，但在我的设备(Galaxy Nexus, Android 4.1)上正常工作之前，我必须调整两件事:

using a copy of TextPaint for measuring layout The documentation for TextView.getPaint() states that it should be used read-only, so I made a copy in both places where we use the paint object for measuring: // 1. in resizeText() if (mAddEllipsis && targetTextSize == mMinTextSize && textHeight > height) { // Draw using a static layout // modified: use a copy of TextPaint for measuring TextPaint paint = new TextPaint(textPaint); // 2. in getTextHeight() 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); ... adding a unit to setting the text size // modified: setting text size via this.setTextSize (instead of textPaint.setTextSize(targetTextSize)) setTextSize(TypedValue.COMPLEX_UNIT_PX, targetTextSize); setLineSpacing(mSpacingAdd, mSpacingMult);

With these two modifications the solution is working perfectly for me, thanks Chase! I don't know whether it is due to Android 4.x that the original solution was not working. In case you want to see it in action or test whether it really works on your device, you can have a look at my flashcard app Flashcards ToGo where I use this solution to scale the text of a flashcard. The text can have arbitrary length, and the flashcards are displayed in different activities, sometimes smaller sometimes bigger, plus in landscape + portrait mode, and I haven't found any corner case where the solution would not work properly...

以下是我为那些还在找工作的人找到的一些东西:

1)这里有一个解决方案，递归重新绘制的textview，直到它适合。这意味着字面上看着你的文本缩小到合适的位置，但至少当它完成时它是合适的。代码需要一些调整才能实现，但基本上已经完成了。

2)你可以试着把一个自定义的解决方案像这样，或dunni的类在这里，这是我所做的使用getPaint().measureText(str)来搜索正确的大小，但它得到了很多混乱，因为我需要它只包装在空白…

3)你可以继续寻找——我已经尝试了数不清的选择。泰德关于StaticLayout的建议对我来说没有回报，但也许有一些东西;我尝试使用StaticLayout.getEllipsis(line)来确定文本是否离开屏幕，但没有效果。在这里可以看到我的帖子(目前没有回复)。