如何从另一个类访问 ImageButton 控件？

Question

JS代码：

<script type="text/javascript">
         function ShowCurrentTime(name) {
         PageMethods.GetCurrentTime(name, OnSuccess);
         }
         function OnSuccess(response, userContext, methodName) {
          alert(response);
         }
</script>

HTML 代码：

<asp:ImageButton ID="IMGBTN001" runat="server" ImageUrl="Images/ico/labaniat.png"
class="img-responsive em-img-lazy" OnClientClick="ShowCurrentTime('01')" />

<asp:Image class="img-responsive retina-img em-img-lazy" ID="IMGMostViewed" runat="server"ImageUrl="Images/Banner/block1_banner.jpg" />

C# 背后的代码

[System.Web.Services.WebMethod]
public static string GetCurrentTime(string name)
{
    //string x = IMGMostViewed.ImageUrl;
    return "Hello " + name + Environment.NewLine + "The Current Time is: "
            + DateTime.Now.ToString();
}

我想从另一个类访问图像。

如何访问 IGMMostViewed 这个 GetCurrentTime 类？

我使用了这段代码，但是得到 "page.FindControl("IMGMostViewed")" return null

    [System.Web.Services.WebMethod]
public static string GetCurrentTime(string name)
{
    if (HttpContext.Current != null)
    {
        Page page = (Page)HttpContext.Current.Handler;
        Image IMGMostViewed = (Image)page.FindControl("IMGMostViewed");
        string x = IMGMostViewed.ImageUrl;
    }
    return "Hello " + name + Environment.NewLine + "The Current Time is: "
            + DateTime.Now.ToString();
}

Answer 1

理论上，您可以将 CurrentHandler 转换为您的页面类型，然后访问您的按钮：

var currentHandler = HttpContext.Current.CurrentHandler as T;
currentHandler.IMGBTN001.ImageUrl = "abc";

更好的方法是在成功函数中访问客户端的按钮。

     function ShowCurrentTime(name) {
      PageMethods.GetCurrentTime(name, OnSuccess);
     }
     function OnSuccess(response, userContext, methodName) {
      //Access here your button and modify it
     }

您还可以在这里找到相关的答案： How to access page controls inside a static web method?