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

这里还有另一个解决方案,只是为了好玩。它可能不是很有效,但它确实处理了文本的高度和宽度,以及有标记的文本。

@Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec)
{
    if ((MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
            && (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)) {

        final float desiredWidth = MeasureSpec.getSize(widthMeasureSpec);
        final float desiredHeight = MeasureSpec.getSize(heightMeasureSpec);

        float textSize = getTextSize();
        float lastScale = Float.NEGATIVE_INFINITY;
        while (textSize > MINIMUM_AUTO_TEXT_SIZE_PX) {
            // Measure how big the textview would like to be with the current text size.
            super.onMeasure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);

            // Calculate how much we'd need to scale it to fit the desired size, and
            // apply that scaling to the text size as an estimate of what we need.
            final float widthScale = desiredWidth / getMeasuredWidth();
            final float heightScale = desiredHeight / getMeasuredHeight();
            final float scale = Math.min(widthScale, heightScale);

            // If we don't need to shrink the text, or we don't seem to be converging, we're done.
            if ((scale >= 1f) || (scale <= lastScale)) {
                break;
            }

            // Shrink the text size and keep trying.
            textSize = Math.max((float) Math.floor(scale * textSize), MINIMUM_AUTO_TEXT_SIZE_PX);
            setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
            lastScale = scale;
        }
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

其他回答

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。

这个解决方案适合我们:

public class CustomFontButtonTextFit extends CustomFontButton
{
    private final float DECREMENT_FACTOR = .1f;

    public CustomFontButtonTextFit(Context context) {
        super(context);
    }

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

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

    private synchronized 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();

            while(size > availableWidth)
            {
                setTextSize( getTextSize() - DECREMENT_FACTOR );
                tp = getPaint();

                tp.getTextBounds(text, 0, text.length(), rect);
                size = rect.width();
            }
        }
    }

    @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);

        if(parentWidth < getSuggestedMinimumWidth())
            parentWidth = getSuggestedMinimumWidth();

        if(parentHeight < getSuggestedMinimumHeight())
            parentHeight = getSuggestedMinimumHeight();

        this.setMeasuredDimension(parentWidth, parentHeight);
    }

    @Override
    protected void onTextChanged(final CharSequence text, final int start,
            final int before, final int after) 
    {
        super.onTextChanged(text, start, before, after);

        refitText(text.toString(), this.getWidth());
    }

    @Override
    protected void onSizeChanged(int w, int h, int oldw, int oldh)
    {
        super.onSizeChanged(w, h, oldw, oldh);

        if (w != oldw) 
            refitText(this.getText().toString(), w);
    }
}

参考ScalableTextView.java这里自动适合Android的TextView。我已经添加了代码来根据文本长度收缩和扩展TextView

AppcompatTextView现在支持从支持库26.0开始自动调整大小。TextView在Android O也以同样的方式工作。更多信息可以在这里找到。一个简单的演示程序可以在这里找到。

<LinearLayout
      xmlns:android="http://schemas.android.com/apk/res/android"
      xmlns:app="http://schemas.android.com/apk/res-auto"
      android:layout_width="match_parent"
      android:layout_height="wrap_content">

      <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        app:autoSizeTextType="uniform"
        app:autoSizeMinTextSize="12sp"
        app:autoSizeMaxTextSize="100sp"
        app:autoSizeStepGranularity="2sp"
      />

</LinearLayout>

这里还有另一个解决方案,只是为了好玩。它可能不是很有效,但它确实处理了文本的高度和宽度,以及有标记的文本。

@Override
protected void onMeasure(final int widthMeasureSpec, final int heightMeasureSpec)
{
    if ((MeasureSpec.getMode(widthMeasureSpec) != MeasureSpec.UNSPECIFIED)
            && (MeasureSpec.getMode(heightMeasureSpec) != MeasureSpec.UNSPECIFIED)) {

        final float desiredWidth = MeasureSpec.getSize(widthMeasureSpec);
        final float desiredHeight = MeasureSpec.getSize(heightMeasureSpec);

        float textSize = getTextSize();
        float lastScale = Float.NEGATIVE_INFINITY;
        while (textSize > MINIMUM_AUTO_TEXT_SIZE_PX) {
            // Measure how big the textview would like to be with the current text size.
            super.onMeasure(MeasureSpec.UNSPECIFIED, MeasureSpec.UNSPECIFIED);

            // Calculate how much we'd need to scale it to fit the desired size, and
            // apply that scaling to the text size as an estimate of what we need.
            final float widthScale = desiredWidth / getMeasuredWidth();
            final float heightScale = desiredHeight / getMeasuredHeight();
            final float scale = Math.min(widthScale, heightScale);

            // If we don't need to shrink the text, or we don't seem to be converging, we're done.
            if ((scale >= 1f) || (scale <= lastScale)) {
                break;
            }

            // Shrink the text size and keep trying.
            textSize = Math.max((float) Math.floor(scale * textSize), MINIMUM_AUTO_TEXT_SIZE_PX);
            setTextSize(TypedValue.COMPLEX_UNIT_PX, textSize);
            lastScale = scale;
        }
    }
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}