Web Forms :: How To Create An Instance Of A Type From Type
Feb 1, 2010How would I create an instance of a type if all I have is the type in string form?
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Now if I wanted to create and instance of myType how would I do that ?
How would I create an instance of a type if all I have is the type in string form?
[Code]....
Now if I wanted to create and instance of myType how would I do that ?
Bit of a puzzler, I have a generic class
public abstract class MyClass<T> : UserControl
{
}
and I have got a type like this
Type type = Type.GetType("Type From DB as String", true, true);
and I want to create and instance of MyClass using the type... But this doesn't work.
MyClass<type> control = (MyClass<type>)LoadControl("/UsercControl.ascx");
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 a basic question about comparing the type of a variable to a specific type. If I have variable A and variable B, both an instance of a certain type, then I know I can compare the types by getting A.GetType and B.GetType, I can also use IsAssignableFrom and IsSubclassOf for more advanced things. However if I only have variable A and I want to know if variable A is of type MyCustomType, as I see it now I first have to create an instance of MyCustome Type, get the type from it and then compare it to the type of A like in the next Example:
string A = "test";
MyCustomType B = new MyCustomType();
Type typeToCompare = B.GetType();
if (A.GetType().FullName == typeToCompare.FullName) {...}
So if I need to know if A is of MyCustomType isn't there an easyer, shorter alternative that I can just try something like the following (which is ofcourse not possible):
if (A.GetType == MyCustomType....) {...}
so without first having to create an instance of the type simply to extract the type from it.?
I'm trying to create a validation layer that will contain methods to validate all my objects (in my Business Objects layer) .. but when I try to reference both the validation and business objects to each other I get a circular dependency error .. so I've decided to create a new layer (BLL) to validate the objects for me and I'll be able to reference both the validation and the object layers.
so I want to build some kind of class/interface -I don't know what fits more- to be like a generic type or a parent type that my method could accept it as a parameter and check for it's Name/ID property. Instead of defining a new method overload for each object type I have
Simplification
I am struggling to find relevant documentation on this, what I basically want to do is to create a 'hyperlink' type and a 'pdf' type that I can put into my XML file and use to link to a webpage or a PDF, with the relevant icon.
Here is my JQuery :
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And my XML :
[Code]....
I am not sure if I have found the right forum for this one.
the problem is:
I have a .licx file in my rootfolder.
I am getting the error:
Error 53 Unable to resolve type ' <add type="TabStrip" version="7.0" />' C:inetpubwwwrootCrop_ApplicationCrop_Applicationeo_web.licx 7 Crop_Application
,which I get for all the types that are in the xml file(i just gave one of them).
A friend told me that I have to add the type .licx in the MIME type in the IIS .
The problem is that I find the MIME type, I add the extension type .licx but I do not know the MIME type for .licx
I have a FormView that allows a user to register for a company event. I want to do a couple of things with this form.
1. I need to write this data to a MS SQL database
2. I need to send an email confirmation of their registration to their email.
I know how to do both of these things, but i am having trouble doing both at the same time.
It would be nice if I could do it in one click, but I coded it into two pages to try to help simplify it.
The first page allows the user to input their information into a formview and when they click the submit button, it places those answers into session variables:
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The Second page confirms the users information by taking those session variables and placing them into labels:
[Code]....
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However, after I place information into the formview on the first page, it throws up this error:
"Conversion from type 'TextBox' to type 'String' is not valid".
I have a gridview which I'm trying to get the display of phonenumbers listed in a certain display format; (xxx) xxx-xxxx.If I have the code such as this, it displays the unformatted phone number and (000) 000-0000 for the null items.
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i 'm working on AIRLINE RESERVATION PORTAL and it's ok how to do this ?
the user most select the number of passenger and passenger's type (Adult,Child,Infant) for example he select 2-adult,3child,1-Infant
and go next , in the next page i have to generate three type of multi application form for each passenger type
2 adult application form
3 Child application form
1 Infant application form
depend on last selected vales , to save the applications in database
I am having problem with rowdatabound, want to add if conditions intact, i am using teh following two if conditions and they don't look right. i found them on google.
If e.Row.RowState = DataControlRowState.Normal Or e.Row.RowState = DataControlRowState.Alternate Then end if
If e.Row.RowState = DataControlRowState.Edit Or e.Row.RowState = 5 Then end if
With datagrids i use these and they work excellent:
If e.Item.ItemType = System.Web.UI.WebControls.ListItemType.Item OrElse e.Item.ItemType = System.Web.UI.WebControls.ListItemType.AlternatingItem Then
end if.....
I have a web in ASP.NET AND CODE IN VB MY DATABASE IS ACCESS WHICH WAS CREATED INITIALLY AND OLD DATA IS ACCESSED FROM THIS ACCESS DATABASE.
THE PROBLEM IS WHEN THE FIELD IS BLANK THE FOLLOWING ERROR COMESĀ
Conversion from type 'DBNull' to type 'String' is not valid.
MY CODE IS AS UNDER
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click
Dim PNO As String = inputtxt.Text
Dim connectString As String = "Provider=Microsoft.Jet.OLEDB.4.0;" & _
"Data Source=C:awingAWing.mdb"
Dim con As OleDbConnection = New OleDbConnection(connectString)
con.Open()
Dim qstr As String
qstr = "select * from PersData where PNO='" + inputtxt.Text + "'"
[Code] .....
I'm trying to pass email addresses from an array to a stored procedure, then display the results in my gridview. I get the following error:No mapping exists from object type System.String[] to a known managed provider native type.On this line: Dim DR As SqlDataReader = MyCommand.ExecuteReader
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I have this error "The given value of type String from the data source cannot be converted to type datetime of the specified target column." when I used sqlbulkcopy to do the transaction
Here is my code:
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I have built a dataset named Transaction_Time.I called it on Page_Load
Transaction_Time tranTme = new Transaction_Time();
put it in the session.
Session["Transaction"] = tranTme;
Then I call that session and cast to dataset.
DataSet dstTranTime = (DataSet)Session["Transaction"];
I got the following error.Unable to cast object of type 'Transaction_Time' to type 'System.Data.DataSet'.
[InvalidCastException: Unable to cast object of type 'Transaction_Time' to type 'System.Data.DataSet'.]
Transaction_Time.Page_Load(Object sender, EventArgs e) in c:InetpubwwwrootWilliam29_11_2010Transaction_Time.aspx.cs:47
System.Web.Util.CalliHelper.EventArgFunctionCaller(IntPtr fp, Object o, Object t, EventArgs e) +14
System.Web.Util.CalliEventHandlerDelegateProxy.Callback(Object sender, EventArgs e) +35
System.Web.UI.Control.OnLoad(EventArgs e) +99
System.Web.UI.Control.LoadRecursive() +50
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +627
It is OK for some other pages. But for some page, it doesn't.
If I have a linq query that creates the anonymous type below:
select new
{
lf.id,
lf.name
lf.desc,
plf.childId
};
Is it possible to assign a specific type to one of the members? Specifically I would like to make lf.id a null-able int rather than an int...
i am using this code for send data to view
[Code]....
Controller e 'System.Collections.Generic.IEnumerable [Code]....
by this code i am render view
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after run the application i got this error
Unable to cast object of type 'System.String' to type 'System.Collections.Generic.IEnumerable`1[BentaAccounting.Models.Repository.AllData]'.
My problem is that when I submit the form and returning my viewModel of type QuestionViewModel - the Type is null.
See code below.
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I'm trying to get a value from a database and I'm getting an error, see code below:
[Code]....
I get and error when I'm trying to convert the value out of the stored procedure to the string SNAME. Error is as follows:
'Conversion from type 'DBNull' to type 'String' is not valid.'
and the stored procedure is as follows:
[Code]....
I get the error - Conversion from type 'DBNull' to type 'Integer' is not valid. - on the line.....
Dim newid As Integer = e.Command.Parameters("@latestRowId").Value.........in vb code behind.
I have the identical code for another page with the exception of the field names and it works fine. The only thing I did differently, as far as I know, is I copied the asp and code behind from the page that works into this page and manually changed the field and table names. I don't know what the problem is. Does anyone see any problems?
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I have an Interface that has its concrete class defined via a factory. Because of this I found no way to use the Interface tpye directly in my LINQ quesry so I had to use the concrete class types to creat a generic list. The LINQ query works but after calling.ToList() on the LINQ query result I get a List(of MyConcreteClass), but I need a List(of IMyConcreteClass). I have tried everything I can find: .Cast, Ctype, implicit casting, etc. but I always get back one of the (2) messages (depending on if I attempt to cast)message:
"Unable to cast object of type 'System.Collections.Generic.List`1[MyConcreteClass]' to type 'System.Collections.Generic.IEnumerable`1[IMyConcreteClass]'."
...or
"Unable to cast object of type '<CastIterator>d__aa`1[IMyConcreteClass]' to type 'System.Collections.Generic.List`1[MyConcreteClass]'."
Here is the sample code:
[Code]....
I have an asp.net web site where I'm trying to resolve what looks like a problem with ASP.NET AJAX:
Microsoft JScript runtime error:
Sys.ArgumentTypeException: Object of
type
'Sys.Extended.UI.AccordionBehavior'
cannot be converted to type
'Sys.UI.Behavior'. Parameter name:
instance
I've googled around a lot, and looked at the code presented (see below, no idea what it means) but no luck.
I've tried changing scriptmanger scriptmode to release, and a bunch of other things too.
Details:
Visual Studio 2010
ASP.NET 4.0
Ajax control toolkit 4.0
jQuery 1.4.2
jQuery UI 1.8.5
JS Code the error occurs in, inside ScriptResource.axd:
dispose:function()
{
var c=this;
b.UI.Behavior.callBaseMethod(c,eb); --------- this line
var d=c._element;
if(d)
{
var f=c.get_name();
if(f)
d[f]=a;
var e=d._behaviors;
Array.remove(e,c);
if(!e.length)
d._behaviors=a;
delete c._element
}
}
Declaration of accordion control:
<%@ Register Assembly="AjaxControlToolkit" Namespace="AjaxControlToolkit" TagPrefix="atlas" %>
(snip)
<atlas:Accordion ID="menu" runat="server" SelectedIndex="0"
ContentCssClass="accordionContent" FadeTransitions="true" FramesPerSecond="30"
TransitionDuration="250" AutoSize="None" Width="270">
</atlas:Accordion>
*Update: *
Added accordion control declaration as requested, is there anything else I can add that could be useful?
Does anyone have any idea about this error at all - am I right in thinking it's MS AJAX not playing nicely with other javascript (probably jQuery UI) on the page?
I seem to be having issues with posting forms with DropDownLists. I've looked all over the net and tried various solutions, but none seem to work for me.
I'm getting the following error: The parameter conversion from type 'System.String' to type 'Models.Organization' failed because no type converter can convert between these types.
Here's my ViewModel:
[Code]....
Here's my controller:
[Code]....
The objects are generated by ADO.NET Entity Framework. Organizations is its own object, but also a property of Profile (each user belongs to one organization). Now I understand what the error message is saying, just not sure how else I'm supposed to do this.
I am making a website to store invoices so i can mail them to clients. So i got a table for clients, invoices and one with invoice products/services. When an invoice has no products/services added to them and it returns null i get the error "the null value cannot be assigned to a member with type System.Decimal which is a non-nullable value type."
I just started with linq. Before i always used mysql. Mostly i just had to call data from 1 table so forgive me if my linq query isn't really correct.
Dim invoices = From i In db.invoices _
Group Join p In db.products On i.id Equals p.invoiceId Into invoiceProducts = Group _
Select New With {i.client.naam, i.titel, (From iP In invoiceProducts Select iP.prijs).Sum}
i show the client's name, the title of the invoice and the total amount the clients will need to pay for products and services.
I'm building a website in vs2010, i generate usercontrols (aspx and ascx pages), if i run the website i get the error : unable to cast object of type 'ASP.ProjectName_master' to type 'ProjectName.master'
I have a folder 'App_Code' under my startproject, that's not a default asp folder any more i think since vs2005, is that maybe the problem?
Under the App_Code folder i have the master.cs file, in this file i get the error.
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