因为file控件上传失败后会自动清空，所以使用文本框来保存上传路径，而且在不同的浏览器下，控件的样式也需要兼容。下面是自己用到的实例
// 初始化判断浏览器的版本，根据版本的不同使用不同的样式
function getExplorer() {
//IE
if (navigator.userAgent.indexOf("MSIE")>=0)
{
document.getElementById("1").style.display = "block";
document.getElementById("2").style.display = "none";
document.getElementById("FileUpload").className = "file";
document.getElementById("box").className = "file-box";
}
//Firefox
else if (navigator.userAgent.indexOf("Firefox")>=0)
{
document.getElementById("1").style.display = "none";
document.getElementById("2").style.display = "block";
document.forms[0].elements["propertyName"].style.width="625px";
}
//Chrome
else if(navigator.userAgent.indexOf("Chrome") >=0)
{
document.getElementById("1").style.display = "block";
document.getElementById("2").style.display = "none";
document.forms[0].elements["propertyName"].style.width="495px";
document.getElementById("ieBtn").style.display = "none";
document.getElementById("FileUpload").style.width = "93px";
}
//Safari
else if(navigator.userAgent.indexOf("Safari") >=0 )
{
document.getElementById("1").style.display = "block";
document.getElementById("2").style.display = "none";
document.forms[0].elements["propertyName"].style.width="585px";
document.getElementById("ieBtn").style.display = "none";
document.getElementById("FileUpload").style.width = "90px";
}
}
样式的代码
.file-box{ position:relative;width:55px}
.btn{ width:55px;}
.file{ position:absolute;top:; right:0px; height:24px; filter:alpha(opacity:0);opacity:;width:0px }
html的代码
由于使用的是struts2
控件的name是formInfo.propertyName
修改的场合时，控件的value是前面的action通过request.setAttribute("Form", pForm)设置的，jsp接收时必须按照下面那么写
<table align="center">
<tr>
<td ><s:textfield name="formInfo.propertyName" value="%{#request.Form.propertyName}" size="512" maxlength="512" style="width:620px;" readonly="true" /></td>
<td id="1">
<div id="box">
<input type="button" value="参照" class="btn" id="ieBtn" />
<input type="file"name="filepropertyName" id="FileUpload" size="1" onchange="Change()" />
</div>
</td>
<td id="2"><input type="button" name="upload" class="btn" id="upload" value="参照" onclick="selectPDF()"/></td>
<td ><input type="button" value="クリア" class="btn" onclick="delPdf()"/></td>
</tr>
</table>
单击按钮把路径显示到文本框中的js
// 当file的值改变时 把路径赋值给文本框
function Change() {
//IE
if (navigator.userAgent.indexOf("MSIE")!=-1||navigator.userAgent.indexOf("Chrome") !=-1||navigator.userAgent.indexOf("Safari") !=-1)
{
var localpath = document.getElementById("FileUpload").value;
document.forms[0].elements["propertyName"].value = localpath;
}
//FF
else if (navigator.userAgent.indexOf("Firefox")!=-1)
{
readFileFirefox()
}
} //FF
function readFileFirefox() {
try {
netscape.security.PrivilegeManager.enablePrivilege("UniversalXPConnect");
}
catch (e) {
return;
} var fileName=document.getElementById("FileUpload").value;
var file = Components.classes["@mozilla.org/file/local;1"]
.createInstance(Components.interfaces.nsILocalFile);
try {
file.initWithPath( fileName.replace(/\//g, "\\\\") );
}
catch(e) {
if (e.result!=Components.results.NS_ERROR_FILE_UNRECOGNIZED_PATH) throw e;
return;
} if ( file.exists() == false ) {
alert("File '" + fileName + "' not found.");
return;
}
document.forms[0].elements["propertyName"].value =file.path;
} // 火狐浏览器下 单击按钮打开file控件 弹出文件选中对话框
function selectPDF()
{
document.forms[0].FileUpload.click();
}