我有一个数据网格,我想使用各种(而不是完美的)
PHP转换器/生成器导出到RTF,PDF等.
我最缺少的是HTML表格根据单元格中字符串的长度自动调整列宽(字符串包含换行符,因为它们应该被保留).
我需要一种算法,给定单元格的内容(纯文本),表格的总宽度和字符的平均宽度将返回每列的宽度.如果已有的东西,我不想重新发明轮子.
当然,如果字体是可变宽度,它可能不是完美的,但近似可以做得很好.或者它可能有一个可配置的表格,每个字符的宽度.
任何提示都将不胜感激.
最佳答案 这不是一件容易的事.
在PHPExcel中,当一个单元格设置为autowidth时,我们使用gd库imagettfbbox()函数
// font size should really be supplied in pixels in GD2,
// but since GD2 seems to assume 72dpi, pixels and points are the same
$fontFile = self::getTrueTypeFontFileFromFont($font);
$textBox = imagettfbbox($font->getSize(), $rotation, $fontFile, $text);
// Get corners positions
$lowerLeftCornerX = $textBox[0];
$lowerLeftCornerY = $textBox[1];
$lowerRightCornerX = $textBox[2];
$lowerRightCornerY = $textBox[3];
$upperRightCornerX = $textBox[4];
$upperRightCornerY = $textBox[5];
$upperLeftCornerX = $textBox[6];
$upperLeftCornerY = $textBox[7];
// Consider the rotation when calculating the width
$textWidth = max($lowerRightCornerX - $upperLeftCornerX, $upperRightCornerX - $lowerLeftCornerX);
return $textWidth;
但它非常密集,特别是在处理大型工作表时,我们也有一种替代(近似)方法
// Calculate column width in pixels. We assume fixed glyph width. Result varies with font name and size.
switch ($fontName) {
case 'Calibri':
// value 8.26 was found via interpolation by inspecting real Excel files with Calibri 11 font.
$columnWidth = (int) (8.26 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 11; // extrapolate from font size
break;
case 'Arial':
// value 7 was found via interpolation by inspecting real Excel files with Arial 10 font.
$columnWidth = (int) (7 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 10; // extrapolate from font size
break;
case 'Verdana':
// value 8 was found via interpolation by inspecting real Excel files with Verdana 10 font.
$columnWidth = (int) (8 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 10; // extrapolate from font size
break;
default:
// just assume Calibri
$columnWidth = (int) (8.26 * PHPExcel_Shared_String::CountCharacters($columnText));
$columnWidth = $columnWidth * $fontSize / 11; // extrapolate from font size
break;
}
// Calculate approximate rotated column width
if ($rotation !== 0) {
if ($rotation == -165) {
// stacked text
$columnWidth = 4; // approximation
} else {
// rotated text
$columnWidth = $columnWidth * cos(deg2rad($rotation))
+ $fontSize * abs(sin(deg2rad($rotation))) / 5; // approximation
}
}
// pixel width is an integer
$columnWidth = (int) $columnWidth;
return $columnWidth;