GetCallbackEventReference不执行任何操作
[英]GetCallbackEventReference doesn't do anything
问题描述
I have an ASP.Net application that must show a label when i changed value from a combo: 
我有一个ASP.Net应用程序，当我从组合更改值时必须显示标签：
in cs file:
在cs文件中： public partial class WebFormAJAXControls : System.Web.UI.Page,System.Web.UI.ICallbackEventHandler { string _callbackArg; public void RaiseCallbackEvent(string eventArgument) { _callbackArg = eventArgument; } public string GetCallbackResult() { return _callbackArg; } protected void Page_Load(object sender, EventArgs e) { //register the name of the client side function that will be called by the server string callbackRef = Page.ClientScript.GetCallbackEventReference(this, "args", "ClientCallbackFunction",""); //define a function used by client to call server string callbackScript = " function MyServerCall(args){alert ('1'); " + callbackRef + " ; }"; //register the client function to the page Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "MyServerCall", callbackScript, true); } }in aspx file:
在aspx文件中： <head runat="server"> <title></title> <script type="text/javascript"> function ClientCallbackFunction(args) { alert(args); LabelMessage.innerText = args; } </script> </head> <body> <form id="form1" runat="server"> <div> <asp:DropDownList ID="DropDownListChoice" runat="server" OnChanged="MyServerCall(DropDownListChoice.value)"> <asp:ListItem>Choise 1</asp:ListItem> <asp:ListItem>Choise 2</asp:ListItem> <asp:ListItem>Choise 3</asp:ListItem> </asp:DropDownList> <br /><br /> <asp:Label ID="labelMessage" runat="server"></asp:Label> </div> </form> </body>
When I change selection in the combobox the program doesn't do anithing.Can somebody tell me what's the problem? 当我在组合框中更改选择时，程序不执行任何操作。有人可以告诉我这是什么问题吗？
2 个解决方案
解决方案1
0 已采纳 2012-10-09 11:10:18
Shouldn't this: 这不应该：
function ClientCallbackFunction(args) {
alert(args);
LabelMessage.innerText = args;
}
be this: 是这样的：
function MyServerCall(args) {
alert(args);
LabelMessage.innerText = args;
}
Currently you don't have a MyServerCall method to invoke. 当前，您没有要调用的MyServerCall方法。
The method you want is OnChange , not OnChanged . 您想要的方法是OnChange ，而不是OnChanged 。 You will also get an error accessing LabelMessage that way. 您还会通过这种方式访问LabelMessage遇到错误。 Something like this with jQuery would do the trick: $('#labelMessage').text(args); jQuery这样的东西可以解决问题： $('#labelMessage').text(args);
解决方案2
0 2012-10-09 11:22:15
Try using RegisterStartupScript to register client script function. 尝试使用RegisterStartupScript注册客户端脚本功能。
Eg: Page.ClientScript.RegisterStartupScript(typeof(Page), "MyServerCall", callbackScript, true); 例如：Page.ClientScript.RegisterStartupScript（typeof（Page），“ MyServerCall”，callbackScript，true）;
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