1、基于PHP的AJAX技術(shù)實(shí)現(xiàn)文件異步上傳本文關(guān)鍵詞： php AJAX 異步上傳 異步的文件上傳是在現(xiàn)代的AJAX實(shí)現(xiàn)的Web應(yīng)用里面經(jīng)常要遇到，必須解決的問(wèn)題。但是標(biāo)準(zhǔn)的AJAX類（XmlHttpRequest）無(wú)法實(shí)現(xiàn)傳輸 文件的功能。因此，這里討論的內(nèi)容就是如何在AJAX的技術(shù)的基礎(chǔ)之上構(gòu)建異步的文件上傳功能。在這個(gè)功能當(dāng)中需要使用到內(nèi)置的框及（IFRAME）來(lái)傳 輸文件。這個(gè)功能實(shí)現(xiàn)的效果是頁(yè)面在上傳文件的時(shí)候，用戶還可以使用該頁(yè)面并且填寫文件描述。 這個(gè)例子是我們引用AJAX的經(jīng)典案例進(jìn)行分析的。系統(tǒng)環(huán)境· 較新版本的瀏覽器。例如Opera，F(xiàn)irefox或者 Intern

2、et Explorer。 · PH 或更高版本 · PHP 5 版本· PHP 中的 'short_open_tag' 選項(xiàng)開(kāi)啟(否則會(huì)發(fā)生解析錯(cuò)誤)。功能分析通過(guò)內(nèi)置的IFRAME（框架）進(jìn)行文件上傳。具備包括三個(gè)部分組成。 · 在頁(yè)面中間有一個(gè)簡(jiǎn)單的form.表單，表單只包含了input type="file" . 控件。這個(gè)表單的目標(biāo)鏈接就是一個(gè)隱藏得IFRAME(通過(guò) CSS的風(fēng)格" display: none;"實(shí)現(xiàn))并且表單里面唯一一個(gè)控件的OnChange事件用來(lái)觸發(fā)JavaScrip

3、t函數(shù)。這個(gè)函數(shù)的作用是檢查用戶提交的擴(kuò)展名，然后提交 表單。 · 在服務(wù)器?php$upload_dir = "/var/www/anyexample/aeu" / 文件存儲(chǔ)的路徑$web_upload_dir = "/aeu" / 文件在Web目錄下的路徑$tf = $upload_dir.'/'.md5(rand().".test"$f = fopen($tf, "w");if ($f = false) die("Fatal error! is not writable.

4、Set 'chmod 777 'or something like this");fclose($f);unlink($tf);/處理上傳的文件if (isset($_POST'fileframe') $result = 'ERROR'$result_msg = 'No FILE field found'if (isset($_FILES'file') / 從瀏覽器接受文件if ($_FILES'file''error' = UPLOAD_ERR_OK) / 沒(méi)有錯(cuò)誤$fi

5、lename = $_FILES'file''name' / 文件名 move_uploaded_file($_FILES'file''tmp_name', $upload_dir.'/'.$filename);/ 處理的主過(guò)程-轉(zhuǎn)移文件到 $upload_dir $result = 'OK'elseif ($_FILES'file''error' = UPLOAD_ERR_INI_SIZE)$result_msg = 'The uploaded file e

6、xceeds the upload_max_filesize directive in php.ini'else $result_msg = 'Unknown error'echo 'htmlheadtitle-/title/headbody'echo 'script language="JavaScript" type="text/javascript"'."n"echo 'var parDoc = window.parent.document;''if

7、 ($result = 'OK')echo 'parDoc.getElementById("upload_status").value = "file successfully uploaded"'echo 'parDoc.getElementById("filename").value = "'.$filename.'"'echo 'parDoc.getElementById("filenamei").value = &q

8、uot;'.$filename.'"'echo 'parDoc.getElementById("upload_button").disabled = false;'elseecho 'parDoc.getElementById("upload_status").value = "ERROR: '.$result_msg.'"'echo "n".'/script/body/html'exit();function saf

9、ehtml($s)$s=str_replace("&", "&", $s);$s=str_replace("", "<", $s);$s=str_replace("", ">", $s);$s=str_replace("'", "'", $s);$s=str_replace(""", """,

10、 $s);return $s;if (isset($_POST'description')$filename = $_POST'filename'$size = filesize($upload_dir.'/'.$filename);$date = date('r', filemtime($upload_dir.'/'.$filename);$description = safehtml($_POST'description');$html =ENDhtmlheadtitle uploaded by

11、 IFRAME Async file uploader/title/headbodyh1/h1pThis is a file information page for your uploaded file. Bookmark it, or send to anyone./ppDate: /ppSize: bytes/ppDescription: pre/pre/ppa href="/" style="font-size: large;"download file/abra href="" style="font-size:

12、small;"back to file uploading/abra href="/upload-log.html" style="font-size: small;"upload-log/a/pbrbrExample by a href="/body/htmlEND;$f = fopen($upload_dir.'/'.$filename.'-desc.html', "w");fwrite($f, $html);fclose($f);$msg = "File upload

13、ed, a href='/-desc.html'see file information page/a"$f = fopen($upload_dir."/upload-log.html", "a");fwrite($f, "p$msg/pn");fclose($f);setcookie('msg', $msg); header("Location: http:/".$_SERVER'HTTP_HOST'.$PHP_SELF); exit(); if (iss

14、et($_COOKIE'msg') && $_COOKIE'msg' != '') if (get_magic_quotes_gpc() $msg = stripslashes($_COOKIE'msg'); else$msg = $_COOKIE'msg'setcookie('msg', ''); ?!- Beginning of main page -htmlheadtitleIFRAME Async file uploader example/title/hea

15、dbody?php if (isset($msg) echo 'p style="font-weight: bold;"'.$msg.'/p'? h1Upload file:/h1pFile will begin to upload just after selection. /ppYou may write file description, while you file is being uploaded./pform action="?=$PHP_SELF?" target="upload_iframe&q

16、uot; method="post" enctype="multipart/form-data"input type="hidden" name="fileframe" value="true"!- Target of the form is set to hidden iframe -!- From will send its post data to fileframe section of this PHP script (see above) -label for="file&

17、quot;text file uploader:/labelbr!- JavaScript is called by OnChange attribute -input type="file" name="file" id="file" onChange="jsUpload(this)"/formscript type="text/javascript"/* This function is called when user selects file in file dialog */funct

18、ion jsUpload(upload_field)/ this is just an example of checking file extensions/ if you do not need extension checking, remove / everything down to line/ upload_field.form.submit();var re_text = /.txt|.xml|.zip/i;var filename = upload_field.value;/* Checking file type */if (filename.search(re_text)

19、= -1)alert("File does not have text(txt, xml, zip) extension");upload_field.form.reset();return false;upload_field.form.submit();document.getElementById('upload_status').value = "uploading file."upload_field.disabled = true;return true;/scriptiframe name="upload_ifra

20、me" style="width: 400px; height: 100px; display: none;"/iframe!- For debugging purposes, it's often useful to remove"display: none" from style="" attribute -brUpload status:brinput type="text" name="upload_status" id="upload_status" value="not uploaded" size="64" disabledbrbrFile name:brinput type="text" name="filenamei" id=&