iText- ColumnText在Rectangle中设置文本适合大小

Question

我想将文本添加到矩形(x,y,w,h)中.文本应该适合矩形的大小(意味着它具有最大尺寸,但它仍然包含在矩形中).
我试着测量文本大小基础BaseFont.getWidthPoint()问题是最终文本大小不能适合rect.它看起来像这样:

这是我的尝试:

  PdfContentByte cb = writer.getDirectContent();
    cb.saveState();
    ColumnText ct = new ColumnText(writer.getDirectContent());
    Font font = new Font(BaseFont.createFont());
    int rectWidth = 80;
    float maxFontSize = getMaxFontSize(BaseFont.createFont(), "text", rectWidth );
    font.setSize(maxFontSize);
    ct.setText(new Phrase("test", font));
    ct.setSimpleColumn(10, 10, rectWidth , 70);
    ct.go();        

    // draw the rect
    cb.setColorStroke(BaseColor.BLUE);
    cb.rectangle(10, 10, rectWidth , 70);
    cb.stroke();
    cb.restoreState();

   // get max font size base on rect width
  private static float getMaxFontSize(BaseFont bf, String text, int width){
    float measureWidth = 1;
    float fontSize = 0.1f;
    float oldSize = 0.1f;
    while(measureWidth < width){
        measureWidth = bf.getWidthPoint(text, fontSize);     
        oldSize = fontSize;
        fontSize += 0.1f;
    }

    return oldSize;
}

你能告诉我我哪里错了吗？

另一个问题,我想测量宽度和高度,文本完全包含在矩形中,并具有最大的字体大小.有没有办法做到这一点？

更新:这是完整的源代码,对我有用:

   private static float getMaxFontSize(BaseFont bf, String text, int width, int height){
   // avoid infinite loop when text is empty
    if(TextUtils.isEmpty(text)){
        return 0.0f;
    }


    float fontSize = 0.1f;
    while(bf.getWidthPoint(text, fontSize) < width){
        fontSize += 0.1f;
    }

    float maxHeight = measureHeight(bf, text, fontSize);
    while(maxHeight > height){
        fontSize -= 0.1f;
        maxHeight = measureHeight(bf, text, fontSize);
    };

    return fontSize;
}

public static  float measureHeight(BaseFont baseFont, String text, float fontSize) 
{ 
    float ascend = baseFont.getAscentPoint(text, fontSize); 
    float descend = baseFont.getDescentPoint(text, fontSize); 
    return ascend - descend; 
}

Answer 1

主要问题

主要问题是您在中使用了错误的参数ct.setSimpleColumn：

ct.setSimpleColumn(10, 10, rectWidth , 70);

与后来的cb.rectangle电话相反

cb.rectangle(10, 10, rectWidth , 70);

其中具有参数float x, float y, float w, float h（w并且h是宽度和高度），该方法ct.setSimpleColumn具有参数float llx, float lly, float urx, float ury（ll是左下方，而ur是右上方）。因此，您ct.setSimpleColumn应该如下所示：

ct.setSimpleColumn(10, 10, 10 + rectWidth, 10 + 70);

附带问题

In addition to the main issue your result font size is 0.1 too large; essentially this is an error already pointed out by @David.

Your main loop in your getMaxFontSize method is this:

while(measureWidth < width){
    measureWidth = bf.getWidthPoint(text, fontSize);     
    oldSize = fontSize;
    fontSize += 0.1f;
}

This essentially results in oldSize (which eventually is returned) being the first font size which does not fit. You could fix this by instead using

while(bf.getWidthPoint(text, fontSize) < width){
    oldSize = fontSize;
    fontSize += 0.1f;
}

Even better would be an approach only calculating the string width once, not using a loop at all, e.g.

private static float getMaxFontSize(BaseFont bf, String text, int width)
{
    int textWidth = bf.getWidth(text);

    return (1000 * width) / textWidth;
}

(This method uses integer arithmetic. If you insist on an exact fit, switch to float or double arithmetic.)