在Ajax控件工具包级联下拉更新 [英] in Cascading dropdown update in Ajax Control Toolkit

问题描述

我收到[MethodError 500]当我使用级联下拉。下面是我的code

 ＆LT; TR＆GT;
＆所述; TD＆GT;
选择主机托管服务提供商：
＆LT; / TD＆GT;
＆所述; TD＆GT;
＆LT; ASP：DropDownList的ID =ddlFeaturedHoster=服务器＆GT;＆LT; / ASP：DropDownList的＆GT;
 ＆LT; / TD＆GT;
 ＆LT; / TR＆GT;
＆LT; ajaxToolkit：CascadingDropDown ID =cddHoster=服务器的TargetControlID =ddlFeaturedHoster
                             PromptText =选择主机托管服务提供商LoadingText =载入中...分类=ActiveHoster
                            ServiceMethod =GetDropDownContentsServicePath =〜/主机/ HostingService.asmx/＆GT;
 

服务code：

  [的WebMethod]
    [ScriptMethod]
    公共CascadingDropDownNameValue [] GetActiveHosters（）
    {        清单＆LT; CascadingDropDownNameValue＆GT; returnList =新的List＆LT; CascadingDropDownNameValue＆GT;（）;
        HostersManager hosterManager =新HostersManager（）;
        清单＆LT; Hosters_HostingProviderDetail＆GT;托管= hosterManager.GetAllHosters（）;
        returnList.Add（新CascadingDropDownNameValue（ - 请选择一个 - ，0，真））;
        的foreach（在托管Hosters_HostingProviderDetail项）
        {
            returnList.Add（新CascadingDropDownNameValue（）{名称= item.HostingProviderName，值= item.HosterID.ToString（）}）;
        }
        返回returnList.ToArray（）;
    }
  [的WebMethod]
    [ScriptMethod]
    公共CascadingDropDownNameValue [] GetDropDownContents（字符串knownCategoryValues​​，串类）
    {
        knownCategoryValues​​ = FormatCategoryWord（knownCategoryValues​​）;
        清单＆LT; CascadingDropDownNameValue＆GT;值=新的List＆LT; CascadingDropDownNameValue＆GT;（）;
        HostersManager hosterManager =新HostersManager（）;
        开关（类别）
        {
            案ActiveHoster：
                values​​.AddRange（GetActiveHosters（））;
                打破;
            案ActiveOffer：
                values​​.AddRange（GetActiveOffers（1））;
                打破;
        }
        返回values​​.ToArray＆LT; CascadingDropDownNameValue＆GT;（）;    }    ///＆LT;总结＆gt;
    ///格式化类别词
    ///＆LT; /总结＆gt;
    ///＆LT; PARAM NAME =值＆GT;＆LT; /参数＆GT;
    ///＆LT;＆回报GT;＆LT; /回报＆GT;
    私人字符串FormatCategoryWord（字符串值）
    {
        如果（string.IsNullOrEmpty（值））的返回值;
        如果（value.LastIndexOf（：）大于0）的值= value.Substring（value.LastIndexOf（：）+ 1）;
        如果（value.LastIndexOf（;）大于0）的值= value.Substring（0，value.LastIndexOf（;））;
        返回值;
    }}
 

解决方案

谈谈你的webMethods内一些尝试catch块一些异常记录？

I am getting [MethodError 500] when I use cascading drop down. below is my code

    <tr>
<td >
Select a Hoster: 
</td>
<td>
<asp:DropDownList ID="ddlFeaturedHoster" runat="server" ></asp:DropDownList>
 </td>
 </tr>


<ajaxToolkit:CascadingDropDown ID="cddHoster" runat="server" TargetControlID="ddlFeaturedHoster"
                             PromptText="Select a Hoster" LoadingText="Loading ..." Category="ActiveHoster"
                            ServiceMethod="GetDropDownContents" ServicePath="~/Hosting/HostingService.asmx"/>

Service Code:

 [WebMethod]
    [ScriptMethod]
    public CascadingDropDownNameValue[] GetActiveHosters()
    {

        List<CascadingDropDownNameValue> returnList = new List<CascadingDropDownNameValue>();
        HostersManager hosterManager = new HostersManager();
        List<Hosters_HostingProviderDetail> hosters = hosterManager.GetAllHosters();
        returnList.Add(new CascadingDropDownNameValue("--Please Select One--","0",true));
        foreach (Hosters_HostingProviderDetail item in hosters)
        {
            returnList.Add(new CascadingDropDownNameValue() {  name=item.HostingProviderName, value= item.HosterID.ToString()});
        }
        return returnList.ToArray() ;
    }
  [WebMethod]
    [ScriptMethod]
    public CascadingDropDownNameValue[] GetDropDownContents(string knownCategoryValues, string category)
    {
        knownCategoryValues = FormatCategoryWord(knownCategoryValues);
        List<CascadingDropDownNameValue> values = new List<CascadingDropDownNameValue>();
        HostersManager hosterManager = new HostersManager();
        switch (category)
        {
            case "ActiveHoster":
                values.AddRange(GetActiveHosters());
                break;
            case "ActiveOffer":
                values.AddRange(GetActiveOffers(1));
                break;
        }
        return values.ToArray<CascadingDropDownNameValue>();

    }

    /// <summary>
    /// Formats the category word
    /// </summary>
    /// <param name="value"></param>
    /// <returns></returns>
    private string FormatCategoryWord(string value)
    {
        if (string.IsNullOrEmpty(value)) return value;
        if (value.LastIndexOf(":") > 0) value = value.Substring(value.LastIndexOf(":") + 1);
        if (value.LastIndexOf(";") > 0) value = value.Substring(0, value.LastIndexOf(";"));
        return value;
    }

}

解决方案

How about some try catch blocks within your webMethods with some exception logging?

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