What is the best way to bind a property to a control so that when the property value is changed, the control's bound property changes with it.So if I have a property "FirstName" which I want to bind to a textbox "txtFirstName" text value. If I change FirstName to "Stack" the txtFirstName.Text also changes to "Stack".
View 1 RepliesNothing binds to my user control. It will bind to other controls. code for UC property:
#Region "IsOn"
'Public Sub IsOnValue_Changed Handles
Public Sub Me_IsOnChanged() Handles Me.IsOnChanged
[Code].....
I develped custom DateTimepicker in vb.net that users can pick date in persian lanquege with it.in my main contrl class i have bindable property with name "Value". here is the property code :
<Editor(GetType(TypeEditor), GetType(UITypeEditor)), Browsable(True), _
Bindable(True)> _
Public Property Value As String
[code].....
I'm trying to create a button that will hide the panel that I have docked at the centre of my user control. [code]This works to an extent. However, when the bottomPanel is set to Fill it seems to fill the entire control, and not just up to toolStrip1. Can anyone tell me why this is happening, and how to correct it?
View 1 RepliesI have a user control with its own context menu, however I need to add additional items to that menu.
The approach I took was to have a dependency property called ContextMenuItems:
Public Shared ReadOnly ContextMenuItemsProperty As DependencyProperty = DependencyProperty.Register("ContextMenuItems", GetType(ObservableCollection(Of MenuItem)), GetType(SmartDataControl), New FrameworkPropertyMetadata(New
[Code].....
In my Winforms application, i've got a form and an associated business layer class. All controls are bound. When i click a button i call a method on the class which then starts a background worker and returns. The background worker does some processing and finishes.
The problem i'm having is that i'm using a label to display any error messages generated by this background worker, which is fine but after a set time i want to clear the label, so for that i'm using a timer (on the business layer class), which, when it fires, is on a different thread and thus should not update the property that the label is bound to Whats the best way to do update the label? -- Should i be using a delegate to update the property value, if so how do i invoke it?Note i'm also having a problem with getting the databinding of the visible property on this label to work.
I have this code
Public Sub FillCategoryCombobox(ByVal categoryList As List(Of tblCategory), ByVal LvName As ComboBox)
LvName.Items.Clear()
Dim itemValue = New Dictionary(Of Integer, String)()
For Each category As tblCategory In categoryList
itemValue.Add(category.CategoryID, category.CategoryName)
Next category
LvName.DataSource = New BindingSource(itemValue, Nothing)
LvName.DisplayMember = "Value"
LvName.ValueMember = "Key"
End Sub
I receive an error on
LvName.DataSource = New BindingSource(itemValue, Nothing)
Value cannot be null
You have a pseudo-table class and a pseudo-row class. The row is somewhat generic and has no strongly-typed fields. It follows the typical dictionary interface
Dim age As Object = person("Age") 'accessed via default property Item
vs
Dim age As Integer = person.Age 'an actual property typed as an Integer
What's the pattern to use so that we can bind our pseudo table and its rows to a grid or combo box?
Dim rs As New clsResultSet(tblPeople)
Dim id As Object = rs(0)("Id") '913
Dim name As Object = rs(0)("Name") 'Ted[code].....
Am in the process of architecting a new windows forms application, and I intend to use Visual Basic 2008 and SQL Server Express 2005. This is my first application in .Net and I really want to observe the best OOD & OOP principles to create an application that is easy to maintain and extend (add new functionality). My issue is in regard to databinding on the UI. From experience, what do you guys recommend to use for databinding? Should I return datasets/datatables from my Business Layer and bind these to UI controls or should I return Business Objects and bind these to UI controls? And what are the pros and cons of each approach?
View 1 RepliesI'm used to webdeveloping, and when I work with databases, I usually use some text for the Text-property of a radio button, and the row's ID as Value-property. This makes it very easy to save to databases.
Is the an equivalent in winforms for the Value-property, or will I have to identify rows based on the text in the control?
The following XAML produces an AmbiguousMatchException. The DataContext for myText is a DataTable consisting of > 1 row which contains a DataColumn named "test":
<TextBox Name="myText" Text="{Binding Path=Rows[0].Item[test]}"/>
When I modify the binding path syntax to the below example, the binding works as expected:
<TextBox Name="myText" Text="{Binding Path=Rows[0][test]}"/>
Given that the name of the DataTable is "myData", both of the following lines of code reference the contents of the column "test" on row 0:
myData.Rows(0)("test")
myData.Rows(0).Item("test")
Why doesn't the syntax that explicitly names the Item property appear to work in a binding scenario?
Say I wanna bind to dictionary that TKey is string with XAML:<Label DataContext="{MyDictionary}" Content="{Binding Item("OK")}" />Doesn't work.How should I do it?
View 1 RepliesI have a project in WPF 4 and VB.net 2010. I want to bind the volume property of a mediaelement to a variable in another module. Mind you, the variable is in the correct data type, so no conversion is necessary
View 1 RepliesFirst, I am making the assumption that anything you can do in "Attribute Syntax" (AS), you can do in "Property Element Syntax" (PES), but not vice-versa. That is the reason I intend on coding completely in PES if possible. I have encountered quirks though.The first issue is regarding AS "x:Name" or PES "<FrameworkElement.Name>": If I use PES, I must make sure it is the last element, otherwise any PES below it will error on build; eg "Value of type 'System.Windows.ResourceDictionary' cannot be converted to 'Namespace.ClassName'."
A problem encountered intermixing AS and PES: Set "x:Name" and "MinWidth" as AS. Set "Title" as PES.
[Code]...
Is there any reason why a picture box wouldn't be saving the image location and loading it into the box the next time the window loads through the picture box property binding 'ImageLocation'?
View 3 RepliesI 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?
since property binding is not working with radio buttons well i am manually writing the code. [code]
View 2 RepliesI have a window that contains different functional areas of an account. The details, roles, type, contracts The window's DataContext is set to the 'AccountViewModel'. Inside the AccountViewModel, there are properties one of them being 'Account' which contains the details. I need for the user to be able to update these details. How can I notifiy the properties to call my Update() code when they are changed?
Here is what I have
<TextBox x:Name="txtAccountNumber" Grid.Row="0" Grid.Column="1" Text="{Binding Path=Account.AccountNumber, UpdateSourceTrigger=LostFocus}" />
[Code]...
I have the following code on a form:
Public Sub Init(ByVal SelectedItems As List(Of Cheque))
Items = New BindingList(Of Cheque)(SelectedItems )
BindingSource1.DataSource = Items
[code]....
This code gets called like so:
...
fmEdit.Init(myList)
fmEdit.Show()
All variables are populated etc, it seems to go through the DataBindings.Add ok but when the form appears I get the error about unable to bind to a property or column called Id. I tried replacing the DataBindings.Add code to use the BindingSource1 instead of Items but I get a similar error.The names of the properties in the class match that of the name in the Databindings.Add code.
UPDATE: Here is my class:
Public Class Cheque
Public Id As String
Public Status As Byte
[code]....
I have a WinForms dialog box that contains 3 radio buttons. I am using ApplicationSettings to bind the Checked property of each of these RadioButton controls, but it doesn't do what I am expecting it to do. Now I have to click each radio button twice before it gets checked and the selected radio button is not being persisted.Is there a line of code I need to execute when the form is closed that saves the user settings?How do I eliminate the need for 2x clicking on the radio buttons?Is there a better way to persist this type of user setting? I do have a public property on the dialog box class that gets/sets an enum value based on which radio button is checked, but I didn't see an easy way of binding that property to a user setting. Should have specified that I'm using vb.net. I think that means My.Settings instead of Properties.Settings.
View 4 RepliesI'm having trouble with some Silverlight functionality. My goal is to get some data from the database and display it in my grid. Sounds simple, however, there are 7 columns that are always going to be there.
The rest of the columns depends on the account. There could be 2 (called Actions) associated with a certain account, compared to another account that could have 5, and the action names can be completely different.
I have successfully been able to return a list of all the possible actions for the given account, and then adding the columns to the grid in the code bihind(VB), and I can bind my data to the grid for all the columns that are already known. The way I store the item's actions, is a Property of type List. My problem is finding a way to iterate through the actions list of the Item object in order to bind those actions to the grid.
During Loading a form, I bind a datasource property of the DGV to the bindingsource, and then set the fillweight property of the DGV columns. But, after form being shown, earlier set properties are being reseted to default = 100.
The procedure is like:
1. TestForm.Show()
2. TestForm_Load(...) Hnadles MyBase.Load
DGV.DataSource = bindingsource
DGV.columns(0).fillweight = 80
DGV.columns(1).fillweight = 120
3. Me.close() (Closing the form which called TestForm.Show()
And now I have visible a TestForm with well binded datasouce seeing all the columns, but their fillweith property was beeing reseted...
I have a custom collection, lets says COL, that derives from ObjectModel.Collection. I have my own collection editor that works fine when a property, of type COL, is Read and Write enabled. However, if I change the property to ReadOnly, the open editor button stops showing in the property grid. As a test, I override my custom editor with the CollectionEditor, and that worked fine. So, my question is, what check is the property grid making, that CollectionEditor passes but my collection editor fails?
View 2 Replieserror in binding
Dadapter = New SqlDataAdapter(dat, conn)
Me.Dadapter.Fill(Me.Table)
bs.DataSource = Me.Table
DgvTire.DataSource = bs
txtserial.DataBindings.Add("text", Table, "serialn")
error: This causes two bindings in the collection to bind to the same property. Parameter name: binding
what should i do with this error?
I've been aware for some time that the Cells() property is early bound but the Cells.Item() property is late bound. In VBA this all works seamlessly apart from the fact that we lose intellisense in the VBA IDE in the latter case:
Code:
'VBA code
Cells. '<---- we get intellisense
Cells(1). '<---- we do not get intellisense
However, in VB .Net with Option Strict On this means that we have an extra consideration in that we have to explicitly convert to an Excel.Range if we want to set the range reference to a range variable:
Code:
'VB .Net code
Option Strict On
Imports Excel = Microsoft.Office.Interop.Excel
'
'
'
Dim oApp As New Excel.Application
[Code] .....
I'm comfortable enough with this because I'm aware of it and it is trivial to handle by explicitly converting to an Excel.Range. We also had a pretty good discussion about the Cells property a little while back in the VBA board which looked at some of its inner workings. My question is to dig a little bit deeper into the way that this has been implemented. I'm trying to get a better understanding about the reasoning behind the Cells.Item() property returning an Object rather than a Excel.Range?
I have added two text boxes - both multiline.and I have the following.vb Private Sub TextBox1_TextChanged(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles TextBox1.TextChanged
[Code]...
I have a class that has a readonly collection property - Its a list of extender providers that have been applied to the control.I've implemented a simple property descriptor for the collection so that the property can be expanded in the property grid to examine each entry.
When I select an extender provider and set it to false, I remove it from the collection. The GetProperties method of the type converter is requeried and the property grid refreshes.However, when I set an extender provider to true, and thus add it to the collection, GetProperties is not requeried.
Somehow, the property grid is making a distinction between adding to and removing from the collection. Or alternativly, its refreshing when an extender provider is added, but not when one is removed.
[Code]...
(I've answered the question below with a hack. I'm fairly confident in it unless MS change the way that codedom serializers the designer code.)ETA2:I've worked out what is going on. I wondered why sometimes it would work and not others. It boils down to the name that I give to the internal property and the collection.If I rename the property 'Annoyance' to 'WTF', it will serialize correctly because 'WTF' is, alphabetically, after the name of the collection - 'InternalAnger'.It looks like the serializer is creating instances of objects alphabetically and needs my internal property to be created by the time it comes to create the collection.I can fix this with a rename, but that's a hack and I fear that writing a custom serializer is a big job - which I've never done before.ETA: Jesus, I'm sick of this. This problem was specifically about persisting an interface collection but now on further testing it doesn't work for a normal collection. Here's some even simpler code:
Public Class Anger
End Class
Public Class MyButton
[code].....
I have a custom control with a bindable property:-
Private _Value As Object
<Bindable(True), ... > _
Public Property Value() As Object
Get
[code]....
Also, here, I'm adding a handler to the DataBindings.CollectionChanged event.This is the second place that I retrieve the type:-
Private Sub DataBindings_CollectionChanged(ByVal sender As Object, ByVal e As System.ComponentModel.CollectionChangeEventArgs)
If e.Action = CollectionChangeAction.Add Then
Dim b As Binding = DirectCast(e.Element, Binding)
[code]....
I need the first place, because the BindingContextChanged event is not fired until some time after InitializeComponent.The second place is needed if the binding field is programatically changed.Am I handling the correct events here, or is there a cleaner way to do it?
Note: My GetValueType method uses the CurrencyManager.GetItemProperties....etc, to retrieve the type.
I have a problem involving late binding, and I absolutely cannot for the life of me figure out how to fix it. I have spent hours researching the problem to no avail, so I am turning to stackoverflow as a last resort.The problem is pretty much this: I am creating a grocery list application. I have a class named Item which stores the name, price, quantity, and description of an item on the grocery list. I have a module named ListCollection which defines a Collection of Item objects. I have created an Edit form which will automatically display the currently selected ListCollection item properties, but whenever I attempt to fill the text boxes, it tells me that Option Strict disallows late binding. I COULD take the easy route and disable Option Strict, but I'd prefer to figure out what the problem is so I know for future reference.I shall paste pertinent code here. (Late binding error is in EditItem.vb)
[code]...
I have tried declaring a String variable and assigning the Item property to that, and I have also tried grabbing the value directly from the List item (not using the Get function), and neither of these made a difference.