使用ReadOnly和Enable(HTML控件:Disabled)都能使用户不能够更改内容,二者区别是:
1、Readonly只针对input(text/password)和textarea有效,而disabled对于所有的表单元素有效,包括select,radio,checkbox,button等。
2、在表单元素使用了disabled后,我们将表单以POST或者GET的方式提交的话,这个元素的值不会被传递出去,而readonly会将该值传递出去。
需要一个这样的文本框,不能手工更改内容,但JS可以,也可以回传。
在页面添加一个Web文本框控件(asp:TextBox),设置为readonly,以为大功告成,谁知道一点击回发,文本框中的内容还是之前的,没改变。于是取消readonly,通过不可焦距、剪切、粘贴等方法让用户不可更改内容,弄出了一个假的不可编辑,哈哈,还挺满足的!
今日得闲,写下如下代码测试。
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<%@ Register Src="~/UC/XwTreeDropDownList/XwTreeDropDownList.ascx" TagPrefix="uc"
TagName="XwTreeDropDownList" %>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<table style="width: 100%;">
<tr>
<td>
</td>
<td>
newReadOnly
</td>
<td>
ReadOnly
</td>
<td>
Disabled
</td>
</tr>
<tr>
<td>
asp:TextBox
</td>
<td>
<asp:TextBox ID="txtNewReadOnly1" runat="server" onfocus="this.blur();" onpaste="return false"
oncut="return false" Text="txtNewReadOnly1"></asp:TextBox>
</td>
<td>
<asp:TextBox ID="txtReadOnly1" runat="server" ReadOnly="true" Text="txtReadOnly1"></asp:TextBox>
</td>
<td>
<asp:TextBox ID="txtDisabled1" runat="server" Enabled="false" Text="txtDisabled1"></asp:TextBox>
</td>
</tr>
<tr>
<td>
input:Text
</td>
<td>
<input runat="server" id="txtNewReadOnly2" type="text" onfocus="this.blur();" onpaste="return false"
oncut="return false" value="txtNewReadOnly2" />
</td>
<td>
<input runat="server" id="txtReadOnly2" type="text" readonly="readonly" value="txtReadOnly2" />
</td>
<td>
<input runat="server" id="txtDisabled2" type="text" disabled="disabled" value="txtDisabled2" />
</td>
</tr>
</table>
<asp:Button ID="Button1" runat="server" Text="回发" OnClick="Button1_Click" />
<input id="Button2" type="button" value="JS设置值" onclick="changeTxtValue();" />
</form>
</body>
</html>
<script type="text/javascript">
function changeTxtValue() {
document.getElementById('txtNewReadOnly1').value = "txtNewReadOnly1" + new Date().getTime();
document.getElementById('txtReadOnly1').value = "txtReadOnly1" + new Date().getTime();
document.getElementById('txtDisabled1').value = "txtDisabled1" + new Date().getTime()
document.getElementById('txtNewReadOnly2').value = "txtNewReadOnly2" + new Date().getTime();
document.getElementById('txtReadOnly2').value = "txtReadOnly2" + new Date().getTime();
document.getElementById('txtDisabled2').value = "txtDisabled2" + new Date().getTime()
}
</script>
protected void Button1_Click( object sender, EventArgs e )
{
Response.Write( "asp:TextBox<br/>" );
Response.Write( string.Format( "txtNewReadOnly1: {0}<br/>", Request.Form[ "txtNewReadOnly1" ] ) );
Response.Write( string.Format( "txtReadOnly1: {0}<br/>", Request.Form[ "txtReadOnly1" ] ) );
Response.Write( string.Format( "txtDisabled1: {0}<br/>", Request.Form[ "txtDisabled1" ] ) );
Response.Write( "<br/>" );
Response.Write( "input:text<br/>" );
Response.Write( string.Format( "txtNewReadOnly2: {0}<br/>", Request.Form[ "txtNewReadOnly2" ] ) );
Response.Write( string.Format( "txtReadOnly2: {0}<br/>", Request.Form[ "txtReadOnly2" ] ) );
Response.Write( string.Format( "txtDisabled2: {0}<br/>", Request.Form[ "txtDisabled2" ] ) );
}
点击“JS设置值”按钮,设置各控件的值,点击“回发”按钮,结果如下:
看到区别了吧!readonly的值是回传了,diabled控件的值没回传,但最奇怪的是,txtReadOnly1和txtReadOnly2回传之后的值居然不一样,Web控件和HTML控件有差别!其实我需要的文本框只需将HTML文本框设置为readonly就ok了,不用那么复杂。
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