I am trying to create a generic list of objects using reflection. The below code throws an error Cannot create an instance of an interface. . I could change the IList to List and it works fine, but I was wondering if there is way to get this working with an IList.
var name = typeof (IList<T>).AssemblyQualifiedName;
Type type = Type.GetType(name);
var list = Activator.CreateInstance(type);
Okay, so I have a Generic IList of custom objects that I want to use as a datasource for a repeater.
[Code]....
In the WebForm inside the repeater, I place this code:
[Code]....
when I try to run it, I get the error "Unable to cast object of type 'System.Collections.Generic.List`1[MyCustomObject]' to type'MyCustomObject'. ". Which makes sense, really.
What's the best way round this? Is there any way I can get the direct cast working? I'm loath to have to create a custom list item that implements IBinding or something and bind that directly, as that'll mean a lot of legacy changes which may create further bugs. Or is there a better way?
I am trying to set property value using reflection as below. I wanted to know if there is any generic way of finding the property type instead of doing it int he below way.
string currentlblTxt;
string currentTxt;
Assembly assembly = Assembly.GetAssembly(typeof(myAdapter));
myAdapter currentEventObject = (myAdapter)assembly.CreateInstance(myClassName);
[code]...
I am trying to create instance of class by using reflection in ASP.net web site. Class ClassName is defined and located in App_code folder. Following line returns null, what could be wrong.
Type type = Type.GetType("NameSpace.ClassName", false, true);
How can I create an instance of a web control at runtime using reflection? I created a series of controls that implement a common interface and I would like to create these controls based on the name of the control which is stored in my database.
I have attempted (and failed) to create an instance of these controls using Activator.CreateInstance in the following ways:
Activator.CreateInstance("MyUserControl")
and
Activator.CreateInstance("ASP","controls_myusercontrol_ascx")
...and both return null.
I've also attempted to simply get the type of the control by trying..
Type t = Type.GetType("controls_myusercontrol_ascx");
and
Type t = Type.GetType("MyUserControl");
...and it returns null.
If I explicitly declare an object as controls_myusercontrol_ascx or MyUserControl, there is no issue -- but it can't be found with reflection.
Is it possible to create web user controls using reflection at run time? If so, how can I?
I have a function that at the moment takes a Type variable. This function sticks it in a list and such and eventually needs will create a class of that type. Right now I do that with
object o=MyType.GetConstructors()[0].Invoke(new object[0]);
which is pretty hacky and also will not work in medium trust due to reflection(I think). Is there a better way of doing this without reflection? The Type is defined this way as part of a function. I need the class to be created "lazily" because it may not be created in the application if it's not needed. I use it for example like
AddToList(typeof(Whatever));
Note, I'm open to suggestions on changing the function calling. I just need the object to be created lazily and for to store the type(or however to create an object of the type) in a list.
I have this code:
Code:
Dim obj1 As New TreeNode
obj1.Value = 1
obj1.Text = "Level" & obj1.Value
Dim obj2 As New TreeNode
obj2.Value = 2
obj2.Text = "Level" & obj2.Value
[Code]...
Can I somehow create a function that creates the nodes instead of I need to make Dim ... each time? If I have 300 nodes this is not a good solution.
I have tried something like this but it doesn't work:
Code:
Function CreateObj(ByVal no As Integer, ByVal name As String, ByVal obj As TreeNode) As TreeNode
obj.Text = "Level" & no
obj.Value = no
treeview1.Nodes.Add(obj)
Return obj
End Function
I have written the following functions(1 & 2) in a class file(say abc.vb) to execute a sql statement in code behind.
[Code]....
I have a user control which has a Gridview and a listview, I want to make this control generic so that I can just pass the type of the class I want to edit, which would be a linq entity, and then it would automatically do the rest, so far I havent had any success and I was wondering if anybody knows a tutorial or some info about doing this?
View 1 RepliesIf I have a the following model
[Code]....
And the following generic control template writer (which would have to be extended appropriately)
[Code]....
I would like to be able to add an attribute either builtin or something I create, such as
[Code]....
The generic template writer would then automatically create a Select box instead of a textbox for this item, and populate it with the list I have passed.
There may need to be another property set to have it write option boxes or radio buttons.
The question has two parts: (1) Is this an appropriate metaphor? and (2) Can you point me to an example that does this or to an appropriate metaphor.
What I want is a generic control writer that looks at the type of the object, writes the appropriate html, and a way to pass in external data for things like lists and enums.
i've got a project requirement in which a webpage developed in asp.net+C# - (used for information gathering from the end user) can be changed to a report view of the same page (after submitting) with dynamic html formatting without affecting the original page can it be done by creating an object of that webpage and modifying its properties or creating an instance of the page or something like that.
View 1 RepliesI Have written code to create instance of an AUTOCAD application.
private void InitializeAutocad()
{
try
{
acApp = (Autodesk.AutoCAD.Interop.AcadApplication)Marshal.GetActiveObject(progID);
}
catch
{
try
{
Type acType = Type.GetTypeFromProgID(progID);
acApp = (Autodesk.AutoCAD.Interop.AcadApplication)Activator.CreateInstance(acType, true);
}
catch(System.Exception ex) { }
}
}
but it throws the above error.
I need to create .net membership user instance for a database living in a different server than the one I'm coding in. What is the best way to do this?Should I do it though Sql Server stored procedure? or should I use a separate provider (therefore having 2) in my web.config?
I need to create this user without using the "create user wizard".
apologies beforehand for what can possibly be a daft conceptual question. I have an ascx control that has a bunch of ASP labels and buttons in the ascx page and some other public methods and properties in the code behind. When I drop this ascx control in a page it all works fine. I now have a page with a placeholder and I am trying to dynamically create an instance of my ascx control and put it there. I then reference this control in code and while all public methods and properties are available (ie MyControl.TitleString = "Hello";MyControl.DoSomething();) none of the ASP controls are. Rather, they are all null. So MyControl.buttonSave is null, MyControl.LabelTitle is null, etc. Is this by design? Am I missing something? If not, what's the point of being able to create dynamically do this?
View 8 RepliesI am building a .net page and need to display some data residing in a database. Some of it's working, some not. I would like to use a table to display the data with the format below..
Table
row - question data
row - answer (count)
row - next answer (count)
row - BarChart representing the answer counts for question
row - next question data
row - answer (count)
row - next answer (count)
row - BarChart representing the answer counts for question
The question data and answer count rows are generated with no issue. However, the rows containing the barchart are problematic. Not sure how to create a new instance of a chart on the fly and hook in all the methods, etc. and get the control added to and displayed in the tablecell. Been looking for examples to create the chart on the fly with no real results.
i m developing a Web Application with C# (with NHibernate)
want to bind the IList with the gridview ...for that i hav to convert IList to datatable .
IMPORTANTLY my Database table that i want to pull(through Nhibernate) contains 3 foreign keys now wat to do convert ?
In Asp.Net 3.5, it is possible that the DataValueField is a IList ?
myddl.DataValueField = "ListOfId"
where ListOfId as a IList in my DataSource
I have recently started to use Nhibernate and i am quite happy with it until i needed to BIND to ASP.NET controls. I was having major issues binding a gridview to a collection of Products (IList). In the end i was forced to right a small routine to convert my IList to a DataTable. Once it was in datatable it worked flawlessy.
Now has come the time to bind a standard Dropdownbox to 1 field of a collection (IList) of Products but it appears i am having issues again.So this has brought me to the conclusion that i must be doing something wrong?I can't believe that it isn't possible to BIND ASP.NET controls to a collection (IList) of a class (in my case products) that is returned from NHibernate.I would really appreciate any feedback anyone has on the situation... I am at a loss
[Code]....
Can we implement through LINQ ?
I have a DataTable that was built from dynamically created SQL, so I do not know the number of columns in the datatable.
How can I convert this datatable into an IList?
EDIT: I am then going to use this to send to a Telerik Grid on the page.
I have a table say, Student.
I have a class 'Student'.
I want to populate IList<Student> with objects of Student class from Student table in database.
Is it possible to implement this?
If yes then how to implement this.
User's need to "download" an excel sheet with data.
However this sheet need to be created on the fly (user's can check of which data they want exported).
From the user's point of view, it will just be a link "Download Now".
From coding point of view I will have an IList<MyClass> where MyClass say got members like EntryId, FirstName, LastName etc.
I do not want all fields to be dropped into the sheet (so I will need control over that in my code)
This sounds like what I'm after (since I'll always only have one sheet)
Create an HTML document and save it with a .xls extension - Excel will open it and treat it like a native Excel file. This method is very simple and, of course, free - however, it won't allow you to have more than one worksheet in the Excel workbook...
I'm trying to create a control out of a class I found, and one of the overridden functions is the following:
protected override void PerformDataBinding(IEnumerable data)
However, when I try to build the control I'm getting the error as shown in the subject. I've tried searching, and it seems the signature for the original function matches the one I have, and all other solutions I've seen uses the same signature.
What is the difference between generic and non-generic collection?
View 1 RepliesI am trying to bind the panel bar with the IList. I have the follwing code in my class libarry
[Code]....
I need to bind the panel bar with getmenuItems. In the above code DataReviw, Score Rep, Something else, section 2 and sample are the parent node of the panel bar and Test1,
/rRepScore/Index,
/something/something,
"Test3",
"/repScoring/Selectreps"
are the childeren of the panel bar and they are the link to another web page.