字符串到图像只产生黑色背景

Question

我确实在找到如何解决此问题时遇到了问题。我似乎无法改变黑色的背景。怎么可能？

$string = "foo";
$font  = 4;
$width  = ImageFontWidth($font) * strlen($string);
$height = ImageFontHeight($font);
$im = @imagecreatetruecolor ($width,$height);
$bg = imagecolorallocate($im, 255, 255, 255);
$textcolor = imagecolorallocate($im, 0, 0, 0);
imagestring($im, 5, 0, 0, $string, $textcolor);
imagegif($im, 'somefile.gif', 8);
imagedestroy($im);

Answer 1

使用：

imagefill($im, 0, 0, $bg);

Answer 2

合并user279470的答案：

$string = "foo";
$font  = 4;
$width  = ImageFontWidth($font) * strlen($string);
$height = ImageFontHeight($font);
$im = @imagecreatetruecolor ($width,$height);
$bg = imagecolorallocate($im, 255, 255, 255);
imagefill($im, 0, 0, $bg);
$textcolor = imagecolorallocate($im, 0, 0, 0);
imagestring($im, 5, 0, 0, $string, $textcolor);
imagepng($im, 'somefile.png', 8);
imagedestroy($im);