[英]How to use ASP.Net server controls inside of Substitution control?
UPDATE這是一個完全正常的示例。 這里發生了一些事情:
這是標記:
<asp:Substitution runat="server" methodname="GetCustomersByCountry" />
這是回調
public string GetCustomersByCountry(string country)
{
CustomerCollection customers = DataContext.GetCustomersByCountry(country);
if (customers.Count > 0)
//RenderView returns the rendered HTML in the context of the callback
return ViewManager.RenderView("customers.ascx", customers);
else
return ViewManager.RenderView("nocustomersfound.ascx");
}
這是呈現用戶控件的幫助器類
public class ViewManager
{
private class PageForRenderingUserControl : Page
{
public override void VerifyRenderingInServerForm(Control control)
{ /* Do nothing */ }
public override bool EnableEventValidation
{
get { return false; }
set { /* Do nothing */}
}
}
public static string RenderView(string path, object data)
{
PageForRenderingUserControl pageHolder = new PageForUserControlRendering();
UserControl viewControl = (UserControl) pageHolder.LoadControl(path);
if (data != null)
{
Type viewControlType = viewControl.GetType();
FieldInfo field = viewControlType.GetField("Data");
if (field != null)
{
field.SetValue(viewControl, data);
}
else
{
throw new Exception("ViewFile: " + path + "has no data property");
}
}
pageHolder.Controls.Add(viewControl);
StringWriter result = new StringWriter();
HttpContext.Current.Server.Execute(pageHolder, result, false);
return result.ToString();
}
}
請參閱以下相關問題:
米卡(Micah )遺漏的一件事是,替換函數必須是static
,必須接受HttpContext
參數並返回string
。 有關更多信息,請參見此msdn頁面 。
我還擴展了Micah的幫助器類,使其更加靈活。
標記
<asp:Substitution ID="Substitution1" MethodName="myFunction" runat="server" />
實施
public static string myFunction(HttpContext httpContext){
ViewManager vm = new ViewManager();
//example using a Button control
Button b = new Button();
b.Text = "click me"; //we can set properties like this
//we can also set properties with a Dictionary Collection
Dictionary<string,object> data = new Dictionary<string,object>();
data.add("Visible",true);
String s = vm.RenderView(b,data); //don't do anything (just for example)
//we can also use this class for UserControls
UserControl myControl = vm.GetUserControl("~mypath");
data.clear();
data.add("myProp","some value");
return vm.RenderView(myControl,data); //return for Substitution control
}
類
using System.IO;
using System.ComponentModel;
public class ViewManager
{
private PageForRenderingUserControl pageHolder;
public ViewManager()
{
pageHolder = new PageForRenderingUserControl();
}
public UserControl GetUserControl(string path)
{
return (UserControl)pageHolder.LoadControl(path);
}
public string RenderView(Control viewControl, Dictionary<string, object> data)
{
pageHolder.Controls.Clear();
//Dim viewControl As UserControl = DirectCast(pageHolder.LoadControl(Path), UserControl)
if (data != null) {
Type viewControlType = viewControl.GetType();
dynamic properties = TypeDescriptor.GetProperties(viewControl);
foreach (string x in data.Keys) {
if ((properties.Item(x) != null)) {
properties.Item(x).SetValue(viewControl, data[x]);
}
}
}
pageHolder.Controls.Add(viewControl);
StringWriter result = new StringWriter();
HttpContext.Current.Server.Execute(pageHolder, result, false);
return result.ToString();
}
private class PageForRenderingUserControl : Page
{
public override void VerifyRenderingInServerForm(Control control)
{
// Do nothing
}
public override bool EnableEventValidation {
get { return false; }
// Do nothing
set { }
}
}
}
再次感謝Micah提供的代碼
我相當確定您不能執行此操作-Substitution控件僅允許您將字符串插入到outputcached頁面中。
如果您考慮服務器控件的整個輸出,則這很有意義,它可能是<table>
,它將破壞您所有精心制作的標記和/或需要在頁面中注入<script>
負載的東西-而注入單個字符串是相對簡單的東西。
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