使用参数调用 WebuserControl 错误 -
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.Services;
using System.Text;
using System.IO;
using System.Reflection;
namespace e_compro
{
public partial class fetchrepeater : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
[WebMethod]
public static string Result(string controlName)
{
// return RenderControl(controlName);
Control toreturn = LoadControl(controlName, "hello");
return toreturn;
}
//public static string RenderControl(string controlName)
//{
// Page page = new Page();
// UserControl userControl = (UserControl)page.LoadControl(controlName);
// userControl.EnableViewState = false;
// HtmlForm form = new HtmlForm();
// form.Controls.Add(userControl);
// page.Controls.Add(form);
// StringWriter textWriter = new StringWriter();
// HttpContext.Current.Server.Execute(page, textWriter, false);
// return textWriter.ToString();
//}
public static UserControl LoadControl(string UserControlPath, params object[] constructorParameters)
{
List<Type> constParamTypes = new List<Type>();
foreach (object constParam in constructorParameters)
{
constParamTypes.Add(constParam.GetType());
}
UserControl ctl = Page.LoadControl(UserControlPath) as UserControl;
// Find the relevant constructor
ConstructorInfo constructor = ctl.GetType().BaseType.GetConstructor(constParamTypes.ToArray());
//And then call the relevant constructor
if (constructor == null)
{
throw new MemberAccessException("The requested constructor was not found on : " + ctl.GetType().BaseType.ToString());
}
else
{
constructor.Invoke(ctl, constructorParameters);
}
// Finally return the fully initialized UC
return ctl;
}
}
}
我已将 LoadControl 方法从受保护的静态方法更改为公共静态方法。我收到第一个参数的错误,该参数是 Webuser 控件 .ascx 文件的位置。
错误 76 非静态字段、方法或属性“System.Web.UI.TemplateControl.LoadControl(string)”需要对象引用
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Web.Services;
using System.Text;
using System.IO;
using System.Reflection;
namespace e_compro
{
public partial class fetchrepeater : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
[WebMethod]
public static string Result(string controlName)
{
// return RenderControl(controlName);
Control toreturn = LoadControl(controlName, "hello");
return toreturn;
}
//public static string RenderControl(string controlName)
//{
// Page page = new Page();
// UserControl userControl = (UserControl)page.LoadControl(controlName);
// userControl.EnableViewState = false;
// HtmlForm form = new HtmlForm();
// form.Controls.Add(userControl);
// page.Controls.Add(form);
// StringWriter textWriter = new StringWriter();
// HttpContext.Current.Server.Execute(page, textWriter, false);
// return textWriter.ToString();
//}
public static UserControl LoadControl(string UserControlPath, params object[] constructorParameters)
{
List<Type> constParamTypes = new List<Type>();
foreach (object constParam in constructorParameters)
{
constParamTypes.Add(constParam.GetType());
}
UserControl ctl = Page.LoadControl(UserControlPath) as UserControl;
// Find the relevant constructor
ConstructorInfo constructor = ctl.GetType().BaseType.GetConstructor(constParamTypes.ToArray());
//And then call the relevant constructor
if (constructor == null)
{
throw new MemberAccessException("The requested constructor was not found on : " + ctl.GetType().BaseType.ToString());
}
else
{
constructor.Invoke(ctl, constructorParameters);
}
// Finally return the fully initialized UC
return ctl;
}
}
}
I have change from protected to public static method for LoadControl method. Im getting this error for the first parameter which is the location of the Webuser control .ascx file.
Error 76 An object reference is required for the non-static field, method, or property 'System.Web.UI.TemplateControl.LoadControl(string)'
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您提供给 LoadControl 的第一个参数是
Type
,其值controlName.GetType().BaseType
等于System.Object
(controlName
是一个string
,string
的基类型是object
) ->错误类型“System.Object”不继承自“System.Web.UI.Control”,因为LoadControl
需要一个System.Web.UI.Control 类型。
您想要实例化一个控件,并给出其名称和名称。一些参数。不幸的是,没有任何版本的
LoadControl
接受这些参数。幸运的是,实现这一目标非常简单。看一下这篇文章:Asp.net 的一个很好的例子具有多个参数的LoadControl。The 1st parameter you're giving to LoadControl is a
Type
and it's valuecontrolName.GetType().BaseType
is equal toSystem.Object
(controlName
is astring
and basetype ofstring
isobject
) -> error Type 'System.Object' does not inherit from 'System.Web.UI.Control' becauseLoadControl
expects aSystem.Web.UI.Control
type.You want to instanciate a control giving it's name & some parameters. Unfortunatly, there is no version of
LoadControl
that accepts those parameters. Fortunatly, it's quite simple to achieve that. Take a look at this article: A Good Example of Asp.net LoadControl with multiple parameters.