I am trying to build a test app to test my objects. I want it to get all the classes/modules from a project/exe/dll then display the methods and allow them to be invoked. I can get a list from the running project, a dll or exe. But I am having trouble filtering.
I would like to use reflection on an anonymous type resulting from a LINQ to SQL query. I know that reflection on anonymous types works in general. The following code successfully generates a propertyinfo array with two elements:
Dim MyObject = New With {.Col1 = 1, .Col2 = "Test"} Dim t As Type = MyObject.GetType() Dim pilist As PropertyInfo() = t.GetProperties
I'm taking a peek at both the Entity Framework and LINQ to SQL, and while I like the systems (and of course the LINQ integration) I'm a little skeptical on the data-binding aspect. I've taken query results and inspected them, and they don't appear to implement the standard .NET list-binding interfaces (IBindingList, and more importantly ITypedList), leading me to believe that binding them to a grid (or anything else) is going to use reflection to get/set my entity properties. This seems like a comparatively expensive operation, especially when all of the code is generated anyway and could implement the interfaces. Is reflection used to get/set the value of the properties?
Edit: I'm actually concentrating on whether or not ITypedList is implemented somewhere along the way, as that's what has the capability to provide an explicit mechanism for defining and interacting with properties without resorting to reflection. While I didn't have a LINQ to SQL project up,I did inspect a simple Entity Framework entity query result, and it did not appear to implement ITypedList.
Edit 2: After accepting Marc's answer, I thought it might be helpful for others if I posted some simple code I used to seamlessly implement his solution. I put the following in the static constructor for my class:
public static ContextName() { foreach(Type type in System.Reflection.Assembly.GetExecutingAssembly()[code]....
While this is for LINQ to SQL, I'm sure an equivalent version could be written for the Entity Framework. This will scan the assembly for any types with the Table attribute and add a custom provider for each of them.
I cannot get the following to work for me: its the section that sets the default for system.data.linq.binary. The database I work with doesn't allow nulls in any field. So I generally run my buffer through this routine to populate defaults and then set the real values independently, (this works when I miss a field). I can set the Linq table field = fakeBinary and it works like a charm. Thus, I don't understand why using reflection can't pull of the same thing. Ex: Me.CM20500WindowBuffer.Reconcile_Messages = New Byte() {0} works.
Try Dim fakeBinary As System.Byte() = {0} For Each fld In nObj.GetType().GetProperties Select Case fld.PropertyType Case GetType(Byte) [Code] .....
OK So I know WHY I am having the error I am getting. I don't know HOW to fix it. Basically, if the user doesn't have a certain permission, I need to join another table. But .NET is so picky I can't just make two different queries in an IF statement and then use it outside of the if statement. I can think of some ugly work arounds for this, but I would rather not. I am fairly new to .NET I know just enough to be dangerous.
[Code]...
because of this: Dim l As IEnumerable(Of Company) its not just IEnumerable of a Company, its got the source in it. I have to explicitly select source to use it in my datagrid. Can I make Dim l something that will make it stop complaining?
I would like to implement a generic Linq query on a DataGridView.DataSource to retreive a row whith an idField. I did search MSDN, StackOverflow, etc... but didn't quite find what I'm looking for. how I could implement it ?
This is the non-generic code, but I would like to make it work whatever the type of the DataSource is (as long as it implements IEnumerable I guess) and the name and type of the key field.
Dim query = (From note In notesList _ Where note.IdNote = mIdNoteSelectionne _ Select note).FirstOrDefault() Dim ancienIndex As Integer = notesList.IndexOf(query)
noteList is a List(Of Note), Note is a simple entity class I created, with just members and properties
This is in VB, but feel free to send some C# code, I'll translate it.
If I used a generic list Class to hold data objects that I am pulling from SQL Server using Linq to sql to populate a datagridview would I need to make any modifications to the datagridview control to accomodate multiple columns or would I need to make any modifications to the generic list class to accomodate the multiple columns in a row that is typical of a record in SQL Server? And one more thing which I believe is the easy part. To bind the list to a datagrid view would I just use the datasource property of the datagridview control.
i need to query the datatable & set the outcome as datagridview controls datasource
vb.net Private Sub Txt_Search_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Txt_Search.TextChanged 'routine objective:- Filter datatable & set the datagridview datasource
I have defined a datagrid which has combobox in one of the columns, is there anyway to modify the datasource of the combobox (the source of the list) at run time?
I am trying to get the valuemember of my combobox but it just won't work. I have tried a lot of things (won't post them all here) can somebody just show me how to do this?
Private Sub cmbGroup_SelectedIndexChanged(ByVal sender As Object, ByVal e As System.EventArgs) Handles cmbGroup.SelectedIndexChanged ' Get valuemember here End Sub
I have a ComboBox that is bound to a List(of T).Now I type-cast the ComboBox.DataSource into List(of T)and add some more elements in the List.The items collection of the ComboBox doesnt get reflected and the new element does not show up in the ComboBox. Am I missing something ?
Private Sub UsernameEdit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load Dim sqlconn As New SqlConnection sqlconn.ConnectionString = "stuff"
[code]....
The combobox just populates with "System.Data.DataRowView" I know it is some command to read the correct data out of the table, is it setting up something like:
dim i as integer for i = 0 to CompanyNames.length-1 companyadapter.fill(companynames.rows(i)] next
just curious what happens when i set the datasource of a combobox or datagrid or what-not to a dt then when i want to change what's in the combobox etc., i just set the datasource to a new one. i am cleaning as i go but just want to know what happens to the old datasource:
I have a combobox which i am binding to a sortedDictionary list, so it displays in ascending order. My question is, I need to display "--Select--" as the first option. Is there any way to either:
1) add another item besides for the datasource
or
2) add an unsorted item to the top of the sortedDictionary
I have to add item "Final Grade" to my cboQuarter. The thing is, my cboQuarter already has a datasource and I can't add the item "Final Grade" during drop-down. The error says, "cannot modify or insert (can't remember word by word) when it already has a datasource."
I have a 2 classes, one is Employee, the other is Employees. Basically Employees is a collection of Employee, I have a combo box where the Datasource is Employees.
When the user selects a value from the combo box, How do I get an Employee object from whatever is selected?[code...]
Appropriate Title would be: Bind comboBox Tag to database.I have a comboBox on form which is bounded but and I need to populate it manually. With some reading on net i have found a way but it is not working
I can populate my combo, select item in combo, update database but the problem is when I load my form it displays empty combo (combo is fulled with my custom data but nothing is selected it must select correct ItemText) and after selecting a value in combo, the value disappears as soon as combo losses focus .
Is it possible to BOTH set a comboboxes datasource AND databind the selected value?Ihave 2 comboboxes on a form that I want to populate with data from 1 table,ut I want the actual selected values on each of the comboboxes to come from separate columns n another datasource Right now if one combobox changes, so does the other if that makes sense.
Here's a sample of code: 'Bind DataSource With cboYields
With code above, how do I assign the value to the combobox while retrieving data from the table so that it point to the corresponding combobox item. For example, if the value of status_ID is 1 then the combobox should show "completed" in the datagridview.
I am using code similar to this to populate a combobox with items from a database. The display works fine, but when I try to get the combobox.SelectedValue it is returning a DataRowView, where I need an integer. Obviously this is becuase I haven't casted the value to an integer, but the function, CInt(cboPosition.SelectedValue) is throwing an InvalidCastException. Is there any way that I can get the ValueMember's type to be an Integer?
Dim cn As New SqlConnection(CreditDisputesLogConn) Dim cmd As New SqlCommand("CustomersLookup", cn) Dim da As New SqlDataAdapter(cmd)
How can I get an item value from a Combobox using a datatable as it's datasource? Here's my code for constructing the combobox. This code works, that's why I'm not showing it all, but I want you to know how I'm creating the combobox.
Try query = "SELECT category_id, name FROM categories ORDER BY name ASC;" dbCommand = New MySqlCommand(query, dbConnection)
[Code]....
I want to display what is the item you physically see in the combobox that you select.
I have this controls ComboBox: list of myobject TextBox: view a description DataSource: list(of MyObject) MyObject:
property id as int property combodesctription as string property description as string
What I want: I set the datasource of combobox with list of MyObject when I select a value on combobox, I would like see description in TextBox is it possible bound text property of TextBox to same datasource of combobox or it is possible change description of TextBox only with changedEvent of ComboBox?
I have a ComboBox which is bound with a DataSource from (obviously) a Database. However, there are 659 different entries inside this Database and I was hoping to tack on AutoComplete.
I tried setting the Source to the ListItems since, after initialization and the data is bound, all the items necessary are in fact inside the ComboBox so I had assumed that it would pick that up. I was wrong. I tried using a Custom source but VS errored out saying that I couldn't do that since the ComboBox was bound.
My question is, how can I utilize AutoComplete's "Suggest" mode with a bound ComboBox?
I've gotten to a point where I'm trying to add a ComboBox to a UserControl, and to populate it from a collection which exists in code.
I've been getting along pretty much on monkey-see-monkey-do coding for the most part; copying and adapting existing code in order to get the next stage working, but this DataSource stuff has me stumped. I've been through a whole bunch of articles on MSDN this morning and am no closer to understanding than I was when I started.
Let me go through a few of the things that are messing with me, and hopefully you guys will be able to point me in the right direction:
1) None of the [UserControlName].vb files contains any code. All of the code for the UserControls is stored in [UserControlName]Model.vb files, and then code of the following sort is used:
1.5) (using bullet points means I can't use <> brackets or code blocks later on. What the hell, markdown?) Anyway...
2) I'm pretty sure I only want a Static Source for the moment, as the items in the ComboBox aren't going to change during execution, at this time. Problem is, all the articles I can find about this are gigantic, complex things about creating XML readers, and populating DataGridViews and sorting data, and on and on and on. I just want to declare that I'm using a frealing List! A List I've already created in code.
So, yeah, I basically need to use a Public Property ComboBoxLines As List(Of String) from a class which isn't the same class as the UserControl itself as the DataSource for a ComboBox.
I have a bound datagridview which populates from the database using parameters. I've added a combobox column through the datagridview properties. How do I access this combobox column datasource?
dbDataSet4 is a typed dataset. I want to learn how to use an Interface. The error message is suggesting using an IList. How would I do this. I'm having trouble finding good documentation on this.
