Overriding DataGridViewTextBoxCell And CellPainting?
Dec 17, 2009
I inherited DataGridViewTextBoxCell because I need to add some custom property to it.
At run-time after creating the DataGridView instance and bind the data I do the following:
For k As Integer = 0 To grid.Columns.Count - 1
grid.Columns(k).AutoSizeMode = DataGridViewAutoSizeColumnMode.ColumnHeader
If k > 0 Then grid.Columns(k).CellTemplate = New CustomCell()
Next
[Code]....
the cell type is never of type CustomCell but it remains DataGridViewTextBoxCell.
I'm trying to paint a cell indicating the progress with number and drawing a background like a progress bar. When I change the cell value it changes the background ok but thnumber looks awfull, only when the percentage bar reaches the number it looks ok, also if i minimisize the form and maximize it, all controls look with the
Private Sub dgLine_CellPainting(ByVal sender As Object, ByVal e As System.Windows.Forms.DataGridViewCellPaintingEventArgs) Handles dgLine.CellPainting
I want to have a DataGridView that has two columns.The first column will always be of type DataGridViewComboBoxColumn. Based on the selection in that column, I'd like to be able to change the corresponding cell in the second column to either a DataGridViewComboBoxCell or a DataGridViewTextBoxCell.I'm thinking I just need to make the second column of type DataGridViewColumn, but don't understand the mechanics of how to change the cell type on the fly.I'm working with VB.NET in Visual Studio 2005.
Update: One way around it, I suppose, is to make the second column as a DataGridViewComboBoxColumn, and change the attributes of the cell so that it either behaves like a drop-down list, or as an (editable) drop-down with no elements. The latter looks enough like a text box that I could live with it, and it wouldn't involve changing the type of the cell.
I am getting the error "Conversion from type 'DataGridViewTextBoxCell' to type 'String' is not valid." When trying to display a cell from DGV in a listbox.I have my variable for the cell reference as follows:
Dim a As Object a = DataGridView1(4,1)
To insert it in the listbox as follows:
lstLetter.Items.Add(String.Format(a))
I tried:
lstLetter.Items.Add(a)
This will not actually display the entry inside the referenced cell, it shows this in my listbox instead:
Protected Overrides Sub Dispose(ByVal disposing As Boolean) Try If disposing = true And components IsNot Nothing Then components.Dispose() End If Finally MyBase.Dispose(disposing) End Try End Sub
Error: Protected Overrides Sub Dispose(disposing As Boolean)' has multiple definitions with identical signatures.How can I call this without raising an error ?
Some of my DataGridViewCells return the wrong value in their GetClipboardContent method. They are cells in a DataGridViewComboBoxColumn cells, so they use the displayed property, not the value property of the cell. I want it to return the value itself.An initial attempt was simply using
Protected Overrides Function GetClipboardContent(ByVal rowIndex As Integer, ByVal firstCell As Boolean, ByVal lastCell As Boolean, ByVal inFirstRow As Boolean, ByVal inLastRow As Boolean, ByVal format As String) As Object Return Value End Function in my DataGridViewComboBoxCell descendant but then I noted that this method is called more than one time per cell value, once for every data format DataGridView supports by standard, which are format="HTML", "Text", "UnicodeText" and "Csv". For csv, the base implementation appends a comma if it's not the last cell, for html it adds the correct tags depending on if it's the first/last row/cell in the table/table row, etc. I consider this format-specific, not cell-value specific.
So how could I replace the value that ends up in the clipboard without re-implementing all those format-specific aspects? That would result in quite some code for functionality that already exists in the base class, wouldn't it?
I have a theoretical class Name_Order, that has a string Name and a int Order. I need to indicate that two Name_Order's are different, if the pair NameOrder is different, that is, or name or order are different. Now, overriding Equals no problemo, but I have some "issues" with GetHashCode:
I have a main class that has a Sub procedure with no implementation. Any derived class should override and implement this procedure, so I used MustOverride in the base class.
Now, any time this procedure is called, I need to set a specific Boolean variable to True at the beginning of the procedure and set it to False at the end.
Is there a way to avoid writing these two lines of code in procedure implementation of every single derived class? Can I set this value to True in the base class, then run procedure in the derived class and then set the value back in the base class?
I am setting my viewmodel as datacontext in my xaml but I override it to my view to make few functions work however to achieve the visibility on some grids and I have a property in my VM can I override my datacontext back to my VM? If so how? I have a stackpanel that has datacontext overriden as my grid and within that stackpanel I need to change the datacontext for a button.
Is it the best override for Equals (in VB.NET) for an object having an unique ID? [code]I took that example from the MSDN, but not entirely sure if from all points of view (including performance) is the better solution.[code]
I know how to handle overriding form closing with FormClosing event and MessageBox prompt by setting e.cancel to true but how can I override deactivation of the mdi child form?
I have a DataViewGrid that is populated with emp records sorted by a 'header' record listing the managers name. Currently, the user is a ble to select any row, even the manager row. I want to modify the program to prevent users from being able to select the manager record or 'header' record
I have an access database for steel members. Each table has a different type of member, and then in those tables, each size of that member type.
I am about to create a tool that draws these sections when they are selected, but as there are 12 different member types, I don't really want to have 12 different Subs for "Draw" that essentially do the same thing.
I considered polymorphism.. (I think I have it correct)
I have a DGV with the Alternating row color set to grey.In the CellFormatting event on the DGV I want to go through the rows as if a cell contains a certain value I want to set the BackColor to red.However when I do this, it just gets overridden with the Alternating grey color. The cell in question in a normal colored row appears in red as expected, just not the alternating row.
rticularly when creating jQuery buttons with no text and just icons) as a result of this.Secondly I am attempting to create my own custom button output by overriding the Render() event and am having a bit of difficulty trying to understand how to go about changing the output that is provided by this event.If I look at the HtmlTextWriter that is provided as the parameter to the Render() event I can see it contains a protected property TagKey = Input {47}, is it possible to simply modify this property somehow and change it to a Button or do I need to create a new instance of the HtmlTextWriter and populate it all from the start? If so, could anyone provide some guidance as to how this would typically be done and if there are any special considerations I need to make to ensure that my derived button class is functionally equivalent to the original (excluding the html)?
<Assembly: TagPrefix("MyCompany", "MyCustomButton")> Public Class MyButton Inherits Button
I would like to use the windows messagebox with for exampleyes' and 'no' buttons on it, but I want to be free to choose the lanuage on the buttons.I mean 'Ja' and 'Nein' or 'Oui' and 'Non' instead of the systems default language.
I've overriden the WndProc of the ComboBox and I am drawing my own combo box, a code snippet is below:
Protected Overrides Sub WndProc(ByRef m As Message) MyBase.WndProc(m) Select Case m.Msg Case &HF
[Code]....
Though the old control is still being painted as my drawn combo box is just overlapping the old drawing. Is there a way to stop it drawing the default combo box?
I was asked to build a winform exe that receives arguments from a web service and decide in which mode the application should start.what is the best way to design and build the application?The application needs to receive 3 arguments.
User name. - stringApplication mode - Boolean (user read write privileges)List on string. Where do I receive this arguments in the new method ?
This is a general question about Object Orientation and specifically overloading functions in .NET (or any other framework or language). I am looking at an application that has a lot of duplicate code. For example, have a look at the following functions: [code] I would of thought that best pratice would be to put: //code that is specifically relevant to Test1 variable in a separate function as it is common in both functions.
I have a custom version of a label control (built using a user control). While working in the designer, I want to intercept the setting of the Name property (in the properties panel) and use it to generate the Text property. That is, if I enter "lblFirstName" into the Name property of the properties panel I want to immediately see that the Text property is set to "First Name". Parsing the Name property is not the issue; I can do that.
I have tried to overload/shadow the Name property (since "Overrides" is not allowed) to essentially add this "aspect" to our custom label control but it doesn't seem to hit the Shadowed method at design time. It does hit the Shadowed method at run time if manipulated via code. The point is to avoid double the work as the label text and the label name are essentially the same. The only difference is one is formatted to be human friendly and the other machine friendly.
<System.ComponentModel.Browsable(True), System.ComponentModel.ParenthesizePropertyName(), System.ComponentModel.DesignerSerializationVisibility(System.ComponentModel.DesignerSerializationVisibility.Visible)> Public Shadows Property Name As String [Code] .....
This may be a matter of picking the right attributes. Conversely, if it's an easier alternative, we could allow setting the Text property to set the Name property. I doubt this would be easier since it should also reflect the new name in the Designer.vb code, not just in the label's Name property itself.
I create a class "Planet" that can be inherited. One of the purposes of inheriting is to create a template with different default property values. Eg:
Public Sub New MyBase.New MyBase.ForeColor = Red
[code]....
Now, to stop the defaults serializing in the InitializeComponent method, there are 2 ways:If I've implemented the properties using the 'DefaultValue' attribute, and made them overridable, the attribute can be overriden with the new value.The problem with this is, there's no way to just make just the attributes overridable, as opposed to the whole property.I could implement every property with protected Reset'PropertyName' and ShouldSerialize'PropertyName' methods. However, this is a bit of a pain in the arse.Is it, generally, an important consideration to ensure that someone who overrides your base class has the ability to change the default values of a property?
I am trying to override a property of a subclass of an inherited base class. I've tried to simplify this code as much as possible but am not comfortable enough with my own abilities to simplify anything else without loosing the ability to understand an answer.The property propertyName in the otherClass is currently incorrect. I want to be able to override propertyName in baseClass with the propertyName in otherClass. Is this possible to accomplish?
Public Interface interfaceName Interface iInterfacePropertyName Enum enumName
Shadows vs. Overrides in VB.Net.What's the difference between shadowing a function in a base class in a subclass and overriding the same function? There is performance issues involved too?I know how to shadow and how to override in VB.net. My question is about when and why should I shadow a function instead override it and vice-versa.
I am using a Hashtable which stores unique names and objects associated with those names. Now those objects have a property called "IsDynamic" and some of them have it set to false whie some of them have it set to true. So when I retrieve any object using the key property, it goes to find me that object. How do I override that find method?
I am overriding the OnRenderButtonBackground method in order to use custom colouring, but I want to know if the mouse is currently over the button. I tried to get the parent control (the toolstrip) and the parent form and add all the co-ordinates together but this is not correct:
Most of our code base is in VB.NET. I'm developing a project in C# that uses a lot of the assemblies from the VB.NET code.There are three relevant classes in VB.NET:
