C# 在asp.net中自动调用文本框textchanged事件
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call text box textchanged event automatically in asp.net
提问by Ankur
I have a form from where I am navigating to a form of mine where I have a text box for quantity. Previously I was entering the quantity. Now, IO have a work flow that is the reason the other form comes in picture. Now, I have extensive coding done my text box text changed event. When I do response.redirectform other form, I flow quantity also and put that quantity in that text box. Now i dont want to write a new code(function) for doing the same as updation procedure will also be done. Following is my code which I am trying to execute and call the text changed event. I am also using update panel. So, is that the reason why my event is not getting fired.? Any solution on that,.??
我有一个表格，从那里我导航到我的一个表格，在那里我有一个数量的文本框。以前我是输入数量。现在，IO 有一个工作流程，这就是另一种形式出现的原因。现在，我对文本框文本更改事件进行了大量编码。当我response.redirect形成其他形式时，我也会流动数量并将该数量放入该文本框中。现在我不想写一个新的代码（函数）来做同样的更新过程。以下是我尝试执行并调用文本更改事件的代码。我也在使用更新面板。那么，这就是我的活动没有被解雇的原因。？任何解决方案，.??
txt_Quantity.TextChanged += new EventHandler(txt_Quantity_TextChanged);
protected void txt_Quantity_TextChanged(object sender, EventArgs e)
{
}
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:Panel ID="pnlGrid" runat="server" BorderColor="#339933" Height="400px" BorderStyle="Solid"
BorderWidth="2px" ScrollBars="Auto" Width="100%">
<div style="height: 40px; width: 100%; background-color: #339933;">
<%-- <img alt="imgrid" src="Images/grid_icon_green.png" style="padding-left: 10px;" />--%>
<span style="font-size: 20px; font-family: Calibri; color: White; padding-left: 5px; vertical-align: top">Asset Distribution</span>
</div>
<AjaxToolKit:TabContainer ID="TabContainer1" runat="server" Height="400px">
<AjaxToolKit:TabPanel ID="tab1" runat="server" TabIndex="0" HeaderText="Basic Information">
<ContentTemplate>
<table width="100%">
<tr>
<td class="r1">Last Code:
</td>
<td>
<asp:Label ID="Lbl_AssetDistriCode" runat="server"></asp:Label>
</td>
<td width="10%" class="r1">Item Code:
</td>
<td width="23%">
<asp:TextBox ID="txt_ItemCode" runat="server" Height="95%" Width="150px" CssClass="txtbxcomp" AutoPostBack="true" OnTextChanged="txt_ItemCode_TextChanged"></asp:TextBox>
<%-- <span style="color: Red;">*</span>--%>
<AjaxToolKit:AutoCompleteExtender ID="AutoCompleteExtender4" runat="server" ServiceMethod="getitem"
ServicePath="WebService.asmx" TargetControlID="txt_ItemCode" CompletionInterval="500"
MinimumPrefixLength="1" EnableCaching="true" CompletionSetCount="5">
</AjaxToolKit:AutoCompleteExtender>
</td>
<td width="10%"></td>
<td width="24%"></td>
</tr>
<tr>
<td class="r1" width="10%">Item Group:
</td>
<td width="23%">
<asp:DropDownList ID="ddl_Item_Grp" runat="server" Height="95%" Width="150px" CssClass="drpComp" AutoPostBack="True"
OnSelectedIndexChanged="ddl_Item_Grp_SelectedIndexChanged">
</asp:DropDownList>
<%-- <span style="color: Red;">*</span>--%>
</td>
<td class="r1" width="10%">Item Type:
</td>
<td width="23%">
<asp:DropDownList ID="ddl_Item_typ" runat="server" Height="95%" Width="150px" CssClass="drpComp" AutoPostBack="True"
OnSelectedIndexChanged="ddl_Item_typ_SelectedIndexChanged">
</asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
<td class="r1" width="14%">Item Catagory:
</td>
<td width="20%">
<asp:DropDownList ID="ddl_Item_cat" runat="server" Height="95%" Width="150px" CssClass="drpComp"></asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
</tr>
<tr>
<td class="r1" width="10%">City:
</td>
<td width="23%">
<asp:DropDownList ID="ddl_city" runat="server" Height="95%" Width="150px" CssClass="drpComp" AutoPostBack="True"
OnSelectedIndexChanged="ddl_city_SelectedIndexChanged">
</asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
<td class="r1" width="10%">Location:
</td>
<td width="24%">
<asp:DropDownList ID="ddl_Loc" runat="server" Height="95%" Width="150px" CssClass="drp"
>
</asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
<td class="r1" width="10%">Branch:
</td>
<td width="23%">
<asp:DropDownList ID="ddl_Branch" runat="server" Height="95%" Width="150px" CssClass="drpComp" AutoPostBack="True"
OnSelectedIndexChanged="ddl_Branch_SelectedIndexChanged">
</asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
</tr>
<tr>
<td class="r1" width="10%">Department:
</td>
<td width="24%">
<asp:DropDownList ID="ddl_Dept" runat="server" Height="95%" Width="150px" CssClass="txtbx" AutoPostBack="True"
OnSelectedIndexChanged="ddl_Dept_SelectedIndexChanged">
</asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
<td class="r1" width="10%">User:
</td>
<td width="23%">
<asp:DropDownList ID="ddl_User" runat="server" Height="95%" width="150px" CssClass="txtbx" AutoPostBack="True"></asp:DropDownList>
<%--<span style="color: Red;">*</span>--%>
</td>
<%--<td class="r1" width="15%">Asset Code:
</td>
<td width="19%">
<asp:DropDownList ID="ddl_Asset_code" runat="server" Height="95%" CssClass="txtbx" AutoPostBack="True"></asp:DropDownList>
<span style="color: Red;">*</span>
</td>--%>
<td class="r1" width="10%">Quantity:
</td>
<td width="23%">
<asp:TextBox ID="txt_Quantity" runat="server" Height="95%" Width="150px" CssClass="txtbxcomp" AutoPostBack="true" OnTextChanged="txt_Quantity_TextChanged"></asp:TextBox>
<cc1:FilteredTextBoxExtender ID="FilteredTextBoxExtender3" runat="server" TargetControlID="txt_Quantity"
ValidChars="0123456789." Enabled="True">
</cc1:FilteredTextBoxExtender>
<%-- <span style="color: Red;">*</span>--%>
</td>
<td width="10%"></td>
<td width="24%"></td>
</tr>
<%--<tr>
<td width="15%" class="r1">Mac ID:
</td>
<td width="18%">
<asp:TextBox ID="txt_MacId" runat="server" Height="95%" CssClass="txtbx"></asp:TextBox>
<span style="color: Red;">*</span>
</td>
<td width="15%"></td>
<td width="18%"></td>
<td width="15%"></td>
<td width="19%"></td>
</tr>--%>
</table>
</ContentTemplate>
</AjaxToolKit:TabPanel>
</ContentTemplate>
<Triggers>
<asp:PostBackTrigger ControlID="btnSave" />
<asp:PostBackTrigger ControlID="btnUpdate" />
<asp:PostBackTrigger ControlID="btndelete" />
<asp:PostBackTrigger ControlID="btnClear" />
</Triggers>
</asp:UpdatePanel>
Thanks in advance.
提前致谢。
回答by R.C
The OnTextChangedwill only occur if you make a change in the textbox and also tab out of the field. OR you can say AutoPostBackon text box will trigger postback when the focus is lost from the text box.
该OnTextChanged如果您在文本框中的变化，也从片场会只发生。或者你可以说AutoPostBack当文本框失去焦点时，文本框会触发回发。
the OnTextChangedevent is NOT fired while you are typing in the text box. OnTextChangedis a server-side event and only fires when the page is posted back. Typing into a text box on a page does not post the page back and so this event will only fire once page is posted by different way like: button click etc.. So you make sure that after the text is changed, you are moving out of text box.
OnTextChanged当您在文本框中键入时，不会触发该事件。OnTextChanged是服务器端事件，仅在页面回发时触发。在页面上的文本框中键入不会回传页面，因此此事件只会在页面以不同方式发布时触发，例如：单击按钮等。因此，请确保在更改文本后，您将移出的文本框。
Using Update panel is fine and once postback happens, TextChanged event will be called too at appropriaate stage of page life cycle.
使用更新面板很好，一旦发生回发，在页面生命周期的适当阶段也会调用 TextChanged 事件。
Also, try to leave the textbox code the same but drop the UpdatePanel. In other words, take AJAX completely out and see if your event is firing during a regular postback (and that you're getting the postback when you expect it). This will surely help narrow down the problem.
此外，尝试保持文本框代码不变，但删除 UpdatePanel。换句话说，完全取消 AJAX 并查看您的事件是否在常规回发期间触发（并且在您期望的时候收到回发）。这肯定有助于缩小问题的范围。
In case, you want this event to fire, everytime a KeyStroke is made( as you type in), This will help: How to make an ASP.NET TextBox fire it's onTextChanged event fire in an AJAX UpdatePanel?
如果您希望在每次进行 KeyStroke 时触发此事件（在您输入时），这将有所帮助：如何使 ASP.NET TextBox 触发它的 onTextChanged 事件在 AJAX UpdatePanel 中触发？
