这是一个可以自动检测你图片大小并生成等比例的缩略图效果，有需要的朋友可以参考一下下哦。
代码如下复制代码*作者：落梦天蝎（beluckly）*完成时间：2006-12-18*类名：creatminiature*功能：生成多种类型的缩略图*基本参数：$srcfile,$echotype*方法用到的参数：$tofile,生成的文件$tow,生成的宽$toh,生成的高$bk1,背景颜色参数 以255为最高$bk2,背景颜色参数$bk3,背景颜色参数*例子：立即学习“PHP免费学习笔记（深入）”；立即学习“PHP免费学习笔记（深入）”；/****************************************作者：落梦天蝎（beluckly）*完成时间：2006-12-18*类名：CreatMiniature*功能：生成多种类型的缩略图*基本参数：$srcFile,$echoType*方法用到的参数：$toFile,生成的文件$toW,生成的宽$toH,生成的高$bk1,背景颜色参数 以255为最高$bk2,背景颜色参数$bk3,背景颜色参数立即学习“PHP免费学习笔记（深入）”；*例子：立即学习“PHP免费学习笔记（深入）”；include("thumb.php");$cm=new CreatMiniature();$cm->SetVar("1.jpg","file");$cm->Distortion("dis_bei.jpg",150,200);$cm->Prorate("pro_bei.jpg",150,200);$cm->Cut("cut_bei.jpg",150,200);$cm->BackFill("fill_bei.jpg",150,200);立即学习“PHP免费学习笔记（深入）”；***************************************/立即学习“PHP免费学习笔记（深入）”；class CreatMiniature{//公共变量var $srcFile=""; //原图var $echoType; //输出图片类型，link--不保存为文件；file--保存为文件var $im=""; //临时变量var $srcW=""; //原图宽var $srcH=""; //原图高立即学习“PHP免费学习笔记（深入）”；//设置变量及初始化function SetVar($srcFile,$echoType){$this->srcFile=$srcFile;$this->echoType=$echoType;立即学习“PHP免费学习笔记（深入）”；$info = "";$data = GetImageSize($this->srcFile,$info);switch ($data[2]){case 1:if(!function_exists("imagecreatefromgif")){echo "你的GD库不能使用GIF格式的图片，请使用Jpeg或PNG格式！返回";exit();}$this->im = ImageCreateFromGIF($this->srcFile);break;case 2:if(!function_exists("imagecreatefromjpeg")){echo "你的GD库不能使用jpeg格式的图片，请使用其它格式的图片！返回";exit();}$this->im = ImageCreateFromJpeg($this->srcFile);break;case 3:$this->im = ImageCreateFromPNG($this->srcFile);break;}$this->srcW=ImageSX($this->im);$this->srcH=ImageSY($this->im);}立即学习“PHP免费学习笔记（深入）”；//生成扭曲型缩图function Distortion($toFile,$toW,$toH){$cImg=$this->CreatImage($this->im,$toW,$toH,0,0,0,0,$this->srcW,$this->srcH);return $this->EchoImage($cImg,$toFile);ImageDestroy($cImg);}立即学习“PHP免费学习笔记（深入）”；//生成按比例缩放的缩图function Prorate($toFile,$toW,$toH){$toWH=$toW/$toH;$srcWH=$this->srcW/$this->srcH;if($toWHPHP 8.5.5PHP 8.5.5 是 PHP 8.5 分支的维护更新版本。该版本延续了“小步快跑”的迭代逻辑，通过深度错误修复、底层性能微调以及安全加固，旨在为开发者提供一个更健壮、更高效的运行环境。该版本严格遵守语义化版本规范，不包含破坏性变更。下载{$ftoW=$toW;$ftoH=$ftoW*($this->srcH/$this->srcW);}else{$ftoH=$toH;$ftoW=$ftoH*($this->srcW/$this->srcH);}if($this->srcW>$toW||$this->srcH>$toH){$cImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);return $this->EchoImage($cImg,$toFile);ImageDestroy($cImg);}else{$cImg=$this->CreatImage($this->im,$this->srcW,$this->srcH,0,0,0,0,$this->srcW,$this->srcH);return $this->EchoImage($cImg,$toFile);ImageDestroy($cImg);}}立即学习“PHP免费学习笔记（深入）”；//生成最小裁剪后的缩图function Cut($toFile,$toW,$toH){$toWH=$toW/$toH;$srcWH=$this->srcW/$this->srcH;if($toWH{$ctoH=$toH;$ctoW=$ctoH*($this->srcW/$this->srcH);}else{$ctoW=$toW;$ctoH=$ctoW*($this->srcH/$this->srcW);}$allImg=$this->CreatImage($this->im,$ctoW,$ctoH,0,0,0,0,$this->srcW,$this->srcH);$cImg=$this->CreatImage($allImg,$toW,$toH,0,0,($ctoW-$toW)/2,($ctoH-$toH)/2,$toW,$toH);return $this->EchoImage($cImg,$toFile);ImageDestroy($cImg);ImageDestroy($allImg);}立即学习“PHP免费学习笔记（深入）”；//生成背景填充的缩图function BackFill($toFile,$toW,$toH,$bk1=255,$bk2=255,$bk3=255){$toWH=$toW/$toH;$srcWH=$this->srcW/$this->srcH;if($toWH{$ftoW=$toW;$ftoH=$ftoW*($this->srcH/$this->srcW);}else{$ftoH=$toH;$ftoW=$ftoH*($this->srcW/$this->srcH);}if(function_exists("imagecreatetruecolor")){@$cImg=ImageCreateTrueColor($toW,$toH);if(!$cImg){$cImg=ImageCreate($toW,$toH);}}else{$cImg=ImageCreate($toW,$toH);}$backcolor = imagecolorallocate($cImg, $bk1, $bk2, $bk3); //填充的背景颜色ImageFilledRectangle($cImg,0,0,$toW,$toH,$backcolor);if($this->srcW>$toW||$this->srcH>$toH){$proImg=$this->CreatImage($this->im,$ftoW,$ftoH,0,0,0,0,$this->srcW,$this->srcH);/*if($ftoW{ImageCopyMerge($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH,100);}else if($ftoH{ImageCopyMerge($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);}*/if($ftoW{ImageCopy($cImg,$proImg,($toW-$ftoW)/2,0,0,0,$ftoW,$ftoH);}else if($ftoH{ImageCopy($cImg,$proImg,0,($toH-$ftoH)/2,0,0,$ftoW,$ftoH);}else{ImageCopy($cImg,$proImg,0,0,0,0,$ftoW,$ftoH);}}else{ImageCopyMerge($cImg,$this->im,($toW-$ftoW)/2,($toH-$ftoH)/2,0,0,$ftoW,$ftoH,100);}return $this->EchoImage($cImg,$toFile);ImageDestroy($cImg);}立即学习“PHP免费学习笔记（深入）”；立即学习“PHP免费学习笔记（深入）”；function CreatImage($img,$creatW,$creatH,$dstX,$dstY,$srcX,$srcY,$srcImgW,$srcImgH){if(function_exists("imagecreatetruecolor")){@$creatImg = ImageCreateTrueColor($creatW,$creatH);if($creatImg)ImageCopyResampled($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);else{$creatImg=ImageCreate($creatW,$creatH);ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);}}else{$creatImg=ImageCreate($creatW,$creatH);ImageCopyResized($creatImg,$img,$dstX,$dstY,$srcX,$srcY,$creatW,$creatH,$srcImgW,$srcImgH);}return $creatImg;}立即学习“PHP免费学习笔记（深入）”；//输出图片，link---只输出，不保存文件。file--保存为文件function EchoImage($img,$to_File){switch($this->echoType){case "link":if(function_exists('imagejpeg')) return ImageJpeg($img);else return ImagePNG($img);break;case "file":if(function_exists('imagejpeg')) return ImageJpeg($img,$to_File);else return ImagePNG($img,$to_File);break;}}立即学习“PHP免费学习笔记（深入）”；}?>