AddWebPart 不能添加动态加载的自定义控件吗?
做了一个自定义控件。强名称。动态加载添加到页面上是可以的。
Assembly asembly = Assembly.LoadFile(@"C:\Inetpub\wwwroot\WebApplication2\WebApplication2\UILib\MyWebControls.dll");
object obj = asembly.CreateInstance("MyWebControls.TestText");
con = LoadControl(obj.GetType(), null);
con.ID = "ddd";
this.Panel1.Controls.Add(con);
但是,如果添加到 WebPartManager里就会出问题:
Assembly asembly = Assembly.LoadFile(@"C:\Inetpub\wwwroot\WebApplication2\WebApplication2\UILib\MyWebControls.dll");
object obj = asembly.CreateInstance("MyWebControls.TestText");
con = LoadControl(obj.GetType(), null);
con.ID = "ddd";
this.WebPartManager1.AddWebPart( this.WebPartManager1.CreateWebPart(con), this.WebPartZone1, 0);
报错:
不能添加 MyWebControls.TestText 类型的控件。类型必须能够被 BuildManager.GetType(string typeName)加载。
请问这是怎么回事,怎么解决?肯请解答。多谢。
源码下载地址: http://ldhyyiqi.cn/upload/动态添加自定义用户控件到%20WebPart.rar
用Reflector 5.0 分析类 WebPartMananger 如下:(只贴主要代码)

Reflector code.
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WebPartManager :
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public WebPart AddWebPart(WebPart webPart, WebPartZoneBase zone, int zoneIndex)
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{
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return this.AddDynamicWebPartToZone(webPart, zone, zoneIndex);
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}
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WebPartManager :
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private WebPart AddDynamicWebPartToZone(WebPart webPart, WebPartZoneBase zone, int zoneIndex)
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{
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WebPart part = this.CopyWebPart(webPart); //这是出错部分.
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this.Internals.SetIsStatic(part, false);
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this.Internals.SetIsShared(part, this.Personalization.Scope == PersonalizationScope.Shared);
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this.AddWebPartToZone(part, zone, zoneIndex);
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this.Internals.AddWebPart(part);
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this.Personalization.CopyPersonalizationState(webPart, part);
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this.OnWebPartAdded(new WebPartEventArgs(part));
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return part;
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}
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WebPartManager
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protected virtual WebPart CopyWebPart(WebPart webPart)
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{
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WebPart part;
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GenericWebPart part2 = webPart as GenericWebPart;
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if (part2 != null)
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{
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Control childControl = part2.ChildControl;
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this.VerifyType(childControl); //这是出错部分.
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Type type = childControl.GetType();
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Control control = (Control) this.Internals.CreateObjectFromType(type);
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control.ID = this.CreateDynamicWebPartID(type);
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part = this.CreateWebPart(control);
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}
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else
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{
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this.VerifyType(webPart);
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part = (WebPart) this.Internals.CreateObjectFromType(webPart.GetType());
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}
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part.ID = this.CreateDynamicWebPartID(webPart.GetType());
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return part;
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}
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WebPartManager
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private void VerifyType(Control control)
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{
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if (!(control is UserControl))
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{
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}
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return;
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Type type = control.GetType();
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string typeName = WebPartUtil.SerializeType(type);
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if (WebPartUtil.DeserializeType(typeName, false) != type) //这是出错部分
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{
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throw new InvalidOperationException(SR.GetString("WebPartManager_CantAddControlType", new object[]
{ typeName }));
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}
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goto Label_003F;
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}
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WebPartUtil:
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internal static Type DeserializeType(string typeName, bool throwOnError)
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{
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return BuildManager.GetType(typeName, throwOnError); //这是出错部分
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}
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BuildManager:
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public static Type GetType(string typeName, bool throwOnError)
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{
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return GetType(typeName, throwOnError, false); //这是出错部分
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}
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BuildManager:
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public static Type GetType(string typeName, bool throwOnError, bool ignoreCase)
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{
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Type t = null;
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if (Util.TypeNameContainsAssembly(typeName))
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{
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t = Type.GetType(typeName, throwOnError, ignoreCase);
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if (t != null)
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{
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return t;
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}
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}
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if (!InitializeBuildManager())
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{
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return Type.GetType(typeName, throwOnError, ignoreCase);
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}
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try
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{
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t = typeof(BuildManager).Assembly.GetType(typeName, false, ignoreCase); //这是出错部分
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}
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catch (ArgumentException exception)
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{
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throw new HttpException(SR.GetString("Invalid_type", new object[]
{ typeName }), exception);
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}
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if (t == null)
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{
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_theBuildManager.EnsureTopLevelFilesCompiled();
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t = Util.GetTypeFromAssemblies(TheBuildManager.TopLevelReferencedAssemblies, typeName, ignoreCase);
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if (t != null)
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{
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return t;
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}
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AssemblyCollection assembliesForAppLevel = CompilationUtil.GetAssembliesForAppLevel();
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if (assembliesForAppLevel != null)
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{
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Type type2 = CompilationUtil.GetTypeFromAssemblies(assembliesForAppLevel, typeName, ignoreCase);
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if (type2 != null)
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{
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if ((t != null) && (type2 != t))
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{
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throw new HttpException(SR.GetString("Ambiguous_type", new object[]
{ typeName, Util.GetAssemblySafePathFromType(t), Util.GetAssemblySafePathFromType(type2) }));
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}
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t = type2;
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}
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}
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if ((t == null) && throwOnError)
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{
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throw new HttpException(SR.GetString("Invalid_type", new object[]
{ typeName }));
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}
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}
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return t;
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}
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分析到这里,就有很多问题了.
typeof(BuildManager).Assembly.GetType(typeName, false, ignoreCase);
这个函数是报错的.单纯的拿这个函数来讲, 我想在指定的程序集里创建对象,但这个函数没有指定程序集.所以只能说,走到这一步,是不对的.
对此,问题似乎有些眉目,如何让 AddWebPart 函数走正确的路.去正确创建.
顺带着的问题是. typeof(BuildManager).Assembly.GetType 这个函数如何使用.
暂时分析到这里.欢迎有相关经验的朋友提出宝贵意见。
问题解决。创建方法如下:
1.把DLL放到 BIN 文件夹下。
2.把生成的代码改为:
Type t = BuildManager.GetType("MyWebControls.TestText", true);
object obj = t.Assembly.CreateInstance("MyWebControls.TestText");
WebControl con = (WebControl)obj;
con.ID = "ddd";
Response.Write(t.FullName);
GenericWebPart gweb = this.WebPartManager1.CreateWebPart(con) ;
Response.Write( gweb.IsStatic ) ;
this.WebPartManager1.AddWebPart(gweb, this.WebPartZone1, 0);
现在,还不清楚是怎么回事。呵。让我给撞上了。哪位朋友给解释一下,BuildManager.GetType 的寻找路径方式?多谢。
如果我想把 DLL 文件放到自定义的文件夹下,该怎么办呢?
(需设置 AppDomainSetup.PrivateBinPath 。)