在TextBox，ASP.NET中处理ENTER按钮

I have the following problem in ASP.NET: there is a form that contains a textbox and a button next to it that is supposed to be pressed by the user after filling the box (sample on http://www.burnthespam.info, click "Pick your one", or when using ReCaptcha in a popup). Often, instead, users press ENTER key to submit the form.

我在ASP.NET中遇到以下问题：有一个表单，其中包含一个文本框和一个旁边的按钮，用户应该在填充框后按下该按钮（http://www.burnthespam.info上的示例，单击“选择一个”，或在弹出窗口中使用ReCaptcha时）。通常，用户按ENTER键提交表单。

This doesn't cause the click event on the button to be triggered and possibly cause an unexpected behaviour. In burnthespam, I "tried" to solve by checking if there is data inside the text box (but now if you do something different than pressing ENTER it's like you pressed it) to workaround it.

这不会导致按钮上的click事件被触发，并可能导致意外行为。在burnthespam中，我“尝试”通过检查文本框内是否有数据来解决（但现在如果你做的不同于按下ENTER，就像你按下它一样）来解决它。

Do you know if there is another way to handle the form submission with ENTER key, or a Javascript snippet that when you press ENTER presses the button I like?

你知道是否有另一种方法来使用ENTER键处理表单提交，或者当你按下ENTER时按下我喜欢的按钮的Javascript片段？

EDIT

I want to handle the ENTER key event on the server-side, ie. I already have

我想在服务器端处理ENTER键事件，即。我已经有了

protected void button_Click(object sender, EventArgs e)
    {
        Response.Redirect(...);
    }

I want that method to be called not only when I submit the form using the button (click or space with it highlighted) but also when a user presses ENTER when focusing the text-box

我希望不仅在我使用按钮提交表单时调用该方法（单击或突出显示空格），而且当用户在聚焦文本框时按ENTER键

EDIT 2

Do you know if it's possible to programmatically click a button in Javascript? Maybe it's not possible to prevent phishing/spamming (see Facebook and "share to friends" for example) but I still would like to ask...

你知道是否有可能以编程方式点击Javascript中的按钮？也许不可能阻止网络钓鱼/垃圾邮件（例如，参见Facebook和“分享给朋友”），但我还是想问...

3 个解决方案

#1

There some ways you can set a default button using the form object DefaultButton property or the DefaultButton property of a panel, but I have found them to be unreliable in the past in various browsers so usually I rely on javascript.

有些方法可以使用表单对象DefaultButton属性或面板的DefaultButton属性设置默认按钮，但我发现它们在过去的各种浏览器中都不可靠，所以通常我依赖于javascript。

The only downside to this code is you have to turn off event validation with a page directive, but it should fire off click events, and trigger validators and all that.

此代码的唯一缺点是您必须使用页面指令关闭事件验证，但它应触发单击事件，并触发验证器以及所有这些。

Here is an example the code that we use. Normally I would put the register function in a utility class, but for this example it is in the page code. Try this out.

这是我们使用的代码示例。通常我会将寄存器函数放在实用程序类中，但对于此示例，它位于页面代码中。试试吧。

<%@ Page Language="C#" EnableEventValidation="false" %>

    <script runat="server">

        protected void cmdSubmit1_Click(object sender, EventArgs e)
        {
            litValue.Text = "Value 1 - You entered: " + txtValue1.Text;
        }
        protected void cmdSubmit2_Click(object sender, EventArgs e)
        {
            litValue.Text = "Value 2 - You entered: " + txtValue2.Text;
        }

        /// <summary>
        /// This function registers what button is clicked based on whatever control currently has focus
        /// so for example if the user password field has focus then you can cause the enter button to click
        /// if the enter key is pressed This works with ie and firefox as far as I know
        /// </summary>
        /// <param name="ControlWithFocus"></param>
        /// <param name="ControlToClick"></param>
        private void RegisterDefaultButton(System.Web.UI.Control ControlWithFocus, System.Web.UI.Control ControlToClick)
        {

            PostBackOptions p = new PostBackOptions(ControlToClick);
            p.PerformValidation = true;
            if (ControlToClick is Button)
            {
                p.ValidationGroup = ((Button)ControlToClick).ValidationGroup;
            }
            else if (ControlToClick is ImageButton)
            {
                p.ValidationGroup = ((ImageButton)ControlToClick).ValidationGroup;
            }
            else if (ControlToClick is LinkButton)
            {
                p.ValidationGroup = ((LinkButton)ControlToClick).ValidationGroup;
            }

            p.RequiresJavaScriptProtocol = false;

            AttributeCollection a = null;
            if (ControlWithFocus is HtmlControl)
            {
                a = ((System.Web.UI.HtmlControls.HtmlControl)ControlWithFocus).Attributes;
            }
            else if (ControlWithFocus is WebControl)
            {
                a = ((System.Web.UI.WebControls.WebControl)ControlWithFocus).Attributes;
            }

            if (a != null)
            {
                a["onKeyDown"] = string.Format("if (event.keyCode == 13) {{{0}}}"
                      , ControlToClick.Page.ClientScript.GetPostBackEventReference(p));
            }
        }


        protected void Page_Load(object sender, EventArgs e)
        {
            RegisterDefaultButton(txtValue1, cmdSubmit1);
            RegisterDefaultButton(txtValue2, cmdSubmit2);

        }

    </script>

    <html xmlns="http://www.w3.org/1999/xhtml">
    <head runat="server">
    </head>
    <body>
        <form id="form1" runat="server">
            Enter Value 1: <asp:TextBox ID="txtValue1" runat="server"></asp:TextBox>
            <br />
            Enter Value 2: <asp:TextBox ID="txtValue2" runat="server"></asp:TextBox>
            <br />
            <asp:Literal ID="litValue" runat="server"></asp:Literal>
            <asp:LinkButton ID="cmdSubmit1" runat="server" Visible="false" OnClick="cmdSubmit1_Click">Hidden Button 1</asp:LinkButton>
            <input id="cmdSubmit2" runat="server" visible="false" type="button" value="Hidden Button 2" onserverclick="cmdSubmit2_Click" />
        </form>
    </body>

#2

Here is an easier way works great for ASP.NET:

这是一个更适合ASP.NET的简单方法：

Add this in your .aspx page

在.aspx页面中添加此内容

<script type="text/javascript">
        function clickButton(e, buttonid) {
            var evt = e ? e : window.event;
            var bt = document.getElementById(buttonid);
            if (bt) {
                if (evt.keyCode == 13) {
                    bt.click();
                    return false;
                }
            }
        }
</script>

And add this on the Page_Load in your aspx.cs file

并在aspx.cs文件的Page_Load中添加它

textbox1.Attributes.Add("onkeypress", "return clickButton(event,'" + buttonName1.ClientID + "')");

#3

You could try this:

你可以试试这个：

<html>
<head>
<script type="text/javascript">
function test(e){
 var keynum;

if(window.event) // IE
{
keynum = e.keyCode
}
else if(e.which) // Netscape/Firefox/Opera
{
keynum = e.which
}   
if(keynum==13) __doPostback('yourButtonId', '');
}
</script>
</head>
<body>
<input type="text" onkeypress="test(event)" />
</body>
</html>

You'll need to replace 'yourButtonId' with the ID that is rendered in the markup for your button, ie the ClientID property in your .NET code. The __doPostback function is the one defined by .NET for handling all of its postbacks.

您需要将“yourButtonId”替换为您的按钮标记中呈现的ID，即.NET代码中的ClientID属性。 __doPostback函数是.NET定义的用于处理其所有回发的函数。