我建立了一个图片库,并按原样保存了图片,但没有对其进行裁剪.我想在将图像加载到控制器中时即时调整图像的大小,因此当我在浏览器中加载控制器时,它会显示图像调整大小后的大小.我已将方法添加到MY_Loader,这是代码.

function show_image($image, $width, $height) {
    $this->helper('file');
    $image_content = read_file($image);

    //resize image
    $image = imagecreatefromjpeg($image);
    $thumbImage = imagecreatetruecolor(50, 50);
    imagecopyresized($thumbImage, $image, 0, 0, 0, 0, 50, 50, $width, $height);
    imagejpeg($thumbImage,"",85);
    imagedestroy($image);
    imagedestroy($thumbImage);

    header('Content-Length: '.strlen($image_content)); // sends filesize header
    header('Content-Type: '. get_mime_by_extension($image)); // send mime-type header
    header('Content-Disposition: inline; filename="'.basename($image).'";'); // sends filename header
    exit($image_content); // reads and outputs the file onto the output buffer
}

从这段代码中,我得到了很多错误,包括标题错误.我究竟做错了什么？

错误：(如果有用)

Message: imagejpeg(): Filename cannot be empty

Message: Cannot modify header information - headers already sent by (output started at /Volumes/www/vhosts/ci/system/core/Exceptions.php:185)

Message: strrchr() expects parameter 1 to be string, resource given

Message: Cannot modify header information - headers already sent by (output started at /Volumes/www/vhosts/ci/system/core/Exceptions.php:185)

Message: basename() expects parameter 1 to be string, resource given

Message: Cannot modify header information - headers already sent by (output started at /Volumes/www/vhosts/ci/system/core/Exceptions.php:185)

解决方法:

好吧…
第一件事是,您不想保存图像,只显示
因此,应仅将imagejpeg与一个参数一起使用.

   function show_image($image, $width, $height) {
        //$this->helper('file');                   why need this?
        //$image_content = read_file($image);      We does not want to use this as output.

        //resize image           
        $image = imagecreatefromjpeg($image);
        $thumbImage = imagecreatetruecolor(50, 50);
        imagecopyresized($thumbImage, $image, 0, 0, 0, 0, 50, 50, $width, $height);
        imagedestroy($image);
        //imagedestroy($thumbImage); do not destroy before display :)
        ob_end_clean();  // clean the output buffer ... if turned on.
        header('Content-Type: image/jpeg');  
        imagejpeg($thumbImage); //you does not want to save.. just display
        imagedestroy($thumbImage); //but not needed, cause the script exit in next line and free the used memory
        exit;
  }

拳头一轮我建议这个变化.请写信给我,什么会因错误而改变…
并建议阅读：http://php.net/manual/en/function.imagecopyresized.php

和这个 ：

       Message: Cannot modify header information - headers already sent by (output started at /Volumes/www/vhosts/ci/system/core/Exceptions.php:185)

对我说,php异常出了点问题…
请检查,BOM字符是在文件开头还是…,..或php标记之后是空格,换行符..一些代码编辑器将这些烦人的字符放在php代码中…

以及所有其他文件(出现此错误消息)都应像这样检查.
有时,在php标记之前还有一些字符…,并且如果在Web服务读取文件时关闭了输出缓冲,则使用默认标头将其发送到输出.
(最近的html / text标头). (如果已经发送了其他标头,则无法发送某些标头.例如,如果发送了html / text,则无法发送image / jpeg)

如果您不想为此工作.我不知道您的系统是什么样的.
我认为index.php是您的引导程序,请对其进行更改.

   <?php
       ob_start();
       .... 
       ob_end_flush();
   ?>

但是更好的解决方案是检查您的php代码,并删除php标记前后的行/字符.