在上一篇中讲解了如何通过Ajax提交表单并由PHP处理底层数据，本篇将主要介绍图片的上传与处理。对于文件的上传很简单，只需一个Form便可实现，再通过PHP将源文件上传到目标目录。先上个效果图：
Sample6_1.php 中创建Form：
//显示上传状态和图片 <div id="showimg"></div> //上传文件需要定义enctype，为了显示图片将target设为uploadframe <form id="uploadform" action="process_upload.php" method="post" enctype="multipart/form-data" target="uploadframe"> Upload a File:<br /> <input type="file" id="myfile" name="myfile" /> //上传文件 <input type="submit" value="Submit"
onclick="uploadimg(document.getElementById('uploadform')); return false;" /> <iframe id="uploadframe" name="uploadframe"
src="process_upload.php" class="noshow"></iframe> </form>
上传图片函数 uploadimg：
function uploadimg(theform){ //提交Form theform.submit(); //在showimg <div>中显示上传状态 setStatus ("Loading...","showimg"); } //上传状态函数 function setStatus (theStatus, theObj){ obj = document.getElementById(theObj); if (obj){ obj.innerHTML = "<div class=\"bold\">" + theStatus + "</div>"; } }
process_upload.php 提供文件上传功能：
<?php //提供图片类型校验 $allowedtypes = array("image/jpeg","image/pjpeg","image/png",
"image/x-png","image/gif"); //文件存放目录 $savefolder = "images"; //如果有文件上传就开始干活 if (isset ($_FILES['myfile'])){ //检查上传文件是否符合$allowedtypes类型 if (in_array($_FILES['myfile']['type'],$allowedtypes)){ if ($_FILES['myfile']['error'] == 0){ $thefile = "$savefolder/".$_FILES['myfile']['name']; //通过move_uploaded_file上传文件 if (!move_uploaded_file($_FILES['myfile']['tmp_name'], $thefile)){ echo "There was an error uploading the file."; } else{ ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <script type="text/javascript" src="functions.js"></script> </head> <body> <!-- 显示图片 --> <img src="<?php echo $thefile; ?>"
onload="doneloading(parent,'<?php echo $thefile; ?>')" /> </body> </html> <?php } } } } ?>
上面代码最后部分的doneloading 函数就是用来显示图片及修改图片尺寸大小。其中会用到thumb.php，它会在images目录中生成出源图片的大、中、小三个尺寸，有兴趣可以研究一下。欢迎大家拍砖～
源代码下载