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.NET Forum / Windows Forms / WinForm Data Binding / August 2007Binding to a business object - Type name does not exist
I know that this is really trivial but has been bugging me for some time and I can't figure out what I'm doing wrong. I have a Windows form and I'm binding a business object (a class defined within the current application and current application namespace). When I define the datasource it creates the following this.tasterBindingSource.DataSource = typeof(TastingMaster.Taster); Which does not compile since the compiler can not resolve the class form how it was specified (namespacename.classname). I get the error The type name 'Taster' does not exist in the type 'TastingMaster.TastingMaster' If I hand edit the above to either this.tasterBindingSource.DataSource = typeof(global::TastingMaster.Taster); or just this.tasterBindingSource.DataSource = typeof(Taster); Things work as expected. So, can someone tell me how I should be doing this to get the code generated correctly the first time? By the way, I used the datasource wizard to create the above.  SignatureNeil Why are you using the type of the object as the data source? surely you need a concrete instance of some class rather than it's type - which is a whole different thing - Data source properties are usually Object based so that you can use any one of the various list, collection or bindinglist style objects so the property will happily accept a type but no sensible binding will take place. Signature-- Bob Powell [MVP] Visual C#, System.Drawing Ramuseco Limited .NET consulting http://www.ramuseco.com Find great Windows Forms articles in Windows Forms Tips and Tricks http://www.bobpowell.net/tipstricks.htm Answer those GDI+ questions with the GDI+ FAQ http://www.bobpowell.net/faqmain.htm All new articles provide code in C# and VB.NET. Subscribe to the RSS feeds provided and never miss a new article. >I know that this is really trivial but has been bugging me for some time >and [quoted text clipped - 26 lines] > > By the way, I used the datasource wizard to create the above. To be fair to the OP, that is exactly what the IDE spits out... the binding code has a special case for Type instances, meaning that it (broadly) uses the TypeDescriptor.GetProperties(type) overload, rather than the TypeDescriptor.GetProperties(object) version. This means that it does, as you would hope, list the properties for the associated Type, rather than the properties of a Type instance. Marc Is this just because you have a form (or other class) or property whose name is the same (in a different namespace), thus confusing the compiler? In which case either the global:: or an alias (using SomeOtherName = blah.bloop.ClassName) directive should suffice. Marc Marc, Thanks for the reply. I don't have any other classes or forms with the same name in any namespace. This happens to be a class that is in a source file with another class and not is a separate .cs file but that should not be the problem. Is there someplace in the IDE where I can specify the global:: so that I don't have to hand edit the designer generated code each time it gets regenerated? Thanks SignatureNeil > Is this just because you have a form (or other class) or property > whose name is the same (in a different namespace), thus confusing the [quoted text clipped - 4 lines] > > Marc Not that I know of. However - on a related note, allow me to warn you that the IDE sometimes gets very flakey about class bindings. If it decides it doesn't like you, it will throw them all away. As such, I tend to only work in the designer until it is "close enough", then I cut/paste the code into a private method (and call it at some point in the Form/Control startup). Any more tweaks I do directly in the snipped code. You don't get to see the columns in the designer, but it tends to last longer. Your mileage may vary ;-p Marc Just as an aside - do you have a fragment (just a few classes etc) that reproduce this? Marc Thanks for the advice on not using the IDE after it gets close. I've been using the Infragistics grid controls and have found that it does decide to discard all my stuff for no known reason so I was moving to your cut/paste approach. I also tried editing the datasource file that had configuration info to see if I could fix it up there ... no luck with that either. As for a sample, I don't have anything that I can do easily but let me see what I can do. I've had exactly the same problem with components that I have in another project where, if I drop them on a form the code generated has the same type issue that I never figured out. SignatureNeil > Just as an aside - do you have a fragment (just a few classes etc) > that reproduce this? > > Marc Free MagazinesGet these publications absolutely FREE for up to 12 months. There are no hidden fees and no obligation. Simply choose a title, complete the application form and submit it. Read more ...
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