出于安全性考虑,JS是不能直接设置File的value值的,下面是我总结出来的方法:
第1个方法是大多人传统做法,替换HTML代码,楼上的已经用到了,我不过是用正则优化一下;
第2个方法利用SendKeys模拟键盘操作,需要允许浏览器调用ActiveX才行;
第3个方法,有点像武侠小说里的"乾坤大挪移"一样,呵呵,看看就知道了!
<
html
>
< head >
< title > 把input file類型的value清空 -- Test by 编程浪子 </ title >
< script >
function clearMethod1() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 0 ];
alert( " \" " + objFile.value + " \"已清除 " );
objFile.outerHTML = objFile.outerHTML.replace( / (value = \ " ).+\"/i, " $ 1 \ "" );
}
function clearMethod2() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 0 ];
alert( " \" " + objFile.value + " \"已清除 " );
var WshShell = new ActiveXObject( " WScript.Shell " );
objFile.focus();
objFile.createTextRange().select();
WshShell.SendKeys( " {del} " );
}
function clearMethod3() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 1 ];
alert( " \" " + objFile.value + " \"已清除 " ); objFile.value = "" ;
}
</ script >
< head >
< body >
< input type = " file " value = " C:\abc.txt " />< br />< br />
< button onclick = " clearMethod1(); " > 清除大法1:李代桃僵 </ button >< br />
< button onclick = " clearMethod2(); " > 清除大法2:暗渡陈仓 </ button >
< br />< br />< br />< br />< br />< br />< br />
< input type = " text " value = "" />< input type = " file " value = " C:\abc.txt " onchange = " this.previousSibling.value=this.value; " style = " width:20 " />< br />< br />
< button onclick = " clearMethod3(); " > 清除大法3:声东击西 </ button >
</ body >
< html >
< head >
< title > 把input file類型的value清空 -- Test by 编程浪子 </ title >
< script >
function clearMethod1() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 0 ];
alert( " \" " + objFile.value + " \"已清除 " );
objFile.outerHTML = objFile.outerHTML.replace( / (value = \ " ).+\"/i, " $ 1 \ "" );
}
function clearMethod2() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 0 ];
alert( " \" " + objFile.value + " \"已清除 " );
var WshShell = new ActiveXObject( " WScript.Shell " );
objFile.focus();
objFile.createTextRange().select();
WshShell.SendKeys( " {del} " );
}
function clearMethod3() {
var objFile = document.getElementsByTagName_r( ' input ' )[ 1 ];
alert( " \" " + objFile.value + " \"已清除 " ); objFile.value = "" ;
}
</ script >
< head >
< body >
< input type = " file " value = " C:\abc.txt " />< br />< br />
< button onclick = " clearMethod1(); " > 清除大法1:李代桃僵 </ button >< br />
< button onclick = " clearMethod2(); " > 清除大法2:暗渡陈仓 </ button >
< br />< br />< br />< br />< br />< br />< br />
< input type = " text " value = "" />< input type = " file " value = " C:\abc.txt " onchange = " this.previousSibling.value=this.value; " style = " width:20 " />< br />< br />
< button onclick = " clearMethod3(); " > 清除大法3:声东击西 </ button >
</ body >
< html >
方法2:暗渡陈仓—>也许是我的环境不支持ActiveX。
方法3:声东击西—>有很大的问题,表面上看值清除了,实际上并没有清除,而且当再次选择文件时,如果所选文件与清除之前是同一文件,那么,text中是不会再显示文件路径的。
所以,还是
objFile.outerHTML=objFile.outerHTML.replace(/(value=\").+\"/i,"$1\"");
才是正解
转载于:https://www.cnblogs.com/diony/archive/2011/04/14/2015910.html