从 Javascript 调用代码隐藏 [英] Calling Code-behind from Javascript

问题描述

点击一个按钮，我调用了一个 JavaScript 函数.获得值后，我需要从代码隐藏中获得的值中执行一些操作.我应该如何调用代码隐藏?

On the click of a button, I call a JavaScript function. After getting the value, I need to perform some stuff from the value obtained in the code-behind. How should I call code-behind?

我的aspx:

function openWindow(page) {
  var getval = window.showModalDialog(page);
  document.getElementById("<%= TxtInput.ClientID %>").value = getval; 
  //After this I need to perform stuff 'Upload(TxtInput.value)' into database from the code-behind
}

调用函数的按钮设置如下:

The button calling the function is set up in the following manner:

<button class="doActionButton" id="btnSelectImage" runat="server" onclick="openWindow('../rcwksheet/popups/uploader.htm')">Select Image</button>

我想要的代码(VB):

My desired code behind (VB):

Public Sub btnSaveImage_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnSelectImage.ServerClick
  Dim inputFile As String = Me.TxtInput.Value
  //do more stuff here
End Sub

所以:

1. 有没有办法从 JavaScript 调用代码隐藏?
2. 我能否以某种方式使用按钮的onclick"属性先转到 JavaScript，然后再转到代码隐藏?
3. 触发 TxtInput.Value 的代码隐藏调用onchange"?

推荐答案

是的，有办法.

首先，在TxtInput中设置好返回值后，可以使用javascript提交表单.

first, you can use javascript to submit the form after your return value is set in TxtInput.

function openWindow(page) {
  var getval = window.showModalDialog(page);
  document.getElementById("<%= TxtInput.ClientID %>").value = getval; 
  document.forms[0].submit();
}

然后在你的代码后面，你可以在页面加载事件中处理 TxtInput 的值.

then in your code behind, you can handle TxtInput's value in page load event.

protected void Page_Load(object sender, EventArgs e)
{
    if (Page.IsPostBack)
    {
        if (this.Input.Value != string.Empty)
        {
            this.Input.Value += "blah";
        }
    }
}

注意:您可能需要识别导致回发的控件

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