在第二次按鈕點擊事件后，javascript函數在asp.net中無法使用c＃

Question

我的問題是，當我點擊按鈕時，javascript函數想要調用。 這個也是工作但是第一次只有在第二次之后我才能調用javascript函數。 我不知道問題出在哪里？

這是我的代碼：

 $(function() { $("#submit_mail").click(function() { validateform(); }); }); function validateform() { var email = $('#txt_emailID').val(); if (email == null || email == "") { alert("Email Should Be Complusory"); return false; } var atposition = email.indexOf("@"); var dotposition = email.lastIndexOf("."); if (atposition < 1 || dotposition < atposition + 2 || dotposition + 2 >= email.length) { alert("Please enter a valid e-mail address...!!!"); return false; } } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="submit" id="submit_mail" value="Send" /> 

Answer 1

嘗試使用事件委托$(document).on("click","#submit_mail",function () { validateform(); });

使用事件委派，您可以為動態元素（在運行時創建）附加事件。

我懷疑你的按鈕是在ajax調用后再次創建的，因為它正在丟失它的事件。

Answer 2

根據我的理解，您需要在validateform()函數中綁定click事件。

請嘗試下面的代碼段。

<script>
    $(function () {
        $("#submit_mail").click(function () {
            validateform();
        });
    });

function validateform() {
    var email = $('#txt_emailID').val();
    if (email == null || email == "") {
        alert("Email Should Be Complusory");
        return false;
    }
    var atposition = email.indexOf("@");
    var dotposition = email.lastIndexOf(".");
    if (atposition < 1 || dotposition < atposition + 2 || dotposition + 2 >= email.length) {
        alert("Please enter a valid e-mail address...!!!");
        $("#submit_mail").unbind();
        $("#submit_mail" ).bind( "click", function() {
          validateform();
        });
        return false;            
    }
    $("#submit_mail").unbind();
    $("#submit_mail" ).bind( "click", function() {
      validateform();
    });
}
</script>

Answer 3

你試過這樣的：

<script>

            function validateform() {
                var email = $('#txt_emailID').val();
                if (email == null || email == "") {
                    alert("Email Should Be Complusory");
                    return false;
                }
                var atposition = email.indexOf("@");
                var dotposition = email.lastIndexOf(".");
                if (atposition < 1 || dotposition < atposition + 2 || dotposition + 2 >= email.length) {
                    alert("Please enter a valid e-mail address...!!!");
                    return false;
                }
            }

    </script>
    <form action="http://example.com/yourpagetoprocess" method="POST" onsubmit="return validateform()">
       <input type="submit" id="submit_mail" value="Send" />
    </form>

Answer 4

這是你的代碼工作。 如果有任何錯誤，請更改：

  $(function () { $("#submit_mail").click(function () { validateform(); }); }); function validateform() { var email = $('#txt_emailID').val(); if (email == null || email == "") { alert("Email Should Be Complusory"); return false; } var atposition = email.indexOf("@"); var dotposition = email.lastIndexOf("."); if (atposition < 1 || dotposition < atposition + 2 || dotposition + 2 >= email.length) { alert("Please enter a valid e-mail address...!!!"); return false; } } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/1.9.1/jquery.min.js"></script> <input type="text" id="txt_emailID" value="" /> <input type="submit" id="submit_mail" value="Send" /> 

Answer 5

 $(function() { $("#submit_mail").click(function() { validateform(); }); $("#submit_mail_1").click(function() { validateform(); }); $("#submit_mail_2").click(function() { validateform(); }); }); function validateform() { var email = $('#txt_emailID').val(); if (email == null || email == "") { alert("Email Should Be Complusory"); return false; } var atposition = email.indexOf("@"); var dotposition = email.lastIndexOf("."); if (atposition < 1 || dotposition < atposition + 2 || dotposition + 2 >= email.length) { alert("Please enter a valid e-mail address...!!!"); return false; } } 

 <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <input type="submit" id="submit_mail" value="Send" /> <input type="submit" id="submit_mail_1" value="Send" /> <input type="submit" id="submit_mail_2" value="Send" />