I know this is random but is there a way to specify that a property explicitly does not need to be inherited? So you can have two sub classes and one object will have that property and the other doesn't?
View 2 RepliesI'm having a few problems converting some code into VB.NET from C#. Most of the translating is done, but I am getting errors when I try to run my code, and I can't figure out what is causing them. Here is the Sub I translated.
Public Sub CreateWidget()
Dim blue As LCDColor
blue.Red = 0
blue.Green = 0
[code]....
The error I receive on this line ("vision.Widgets.CreateWidget(wg1)") reads "In order to evaluate an indexed property, the property must be qualified and the arguments must be explicitly supplied by the user."
I receive a System.Data.SqlClient.SqlException in the following code: Specifically Incorrect syntax near ' In order to evaluate an indexed property, the property must be qualified and the arguments must be explicitly supplied by the user. The exception detail in its entirety is shown below the code.
[Code]...
While running the code I've included below I receive the error "EntityCommandExecutionException was unhandled by user code.I'm then told to look at the inner exception for details...and there I see under Data:"In order to evaluate an indexed property, the property must be qualified and the arguments must be explicitly supplied by the user."And under Inner Exception --> Message:"A transport-level error has occurred when receiving results from the server.[code]
View 2 RepliesOn form1 I put a picturebox from the toolbox.[code]Is it possible to set picturebox.visible=true of the inherited picturebox?
View 1 RepliesIn the book I am reading the writer shows code for adding the WordWrap property to a class which inherits System.Windows.Forms.UserControl. But what is the point? There is nowhere to insert strings! Also he shows how to add an event by embedding a Combo in an instance of the class and using its SelectedIndexChanged event to raise the event for the UserControl; again what is the point?
View 5 RepliesI am creating an Extended DateTime picker. I have created a Class the inherits the Default DateTimePicker and Adds a new Property NullableValue. I have placed the control on a form and bound it to a Binding Source using the NullableValue Property. When I load the record the control updates as it should. But when I change the value and save it does not save back to the database.
[Code]...
I've removed the properties completely with a controlDesigner class, but I'm getting warnings + trying to do it properly to remove those warnings.
View 6 RepliesI have a class that exposes an auto implemented property Enabled
[Code]...
But If I had not use an auto implemented property and declared my own backing-field as follows this is accessible from the subclass: Private _Enabled as Boolean ---- EDIT ----
The abve line is incorrect - this is not possible, it was in fact Protected in the original code which allowed access from the sub class See @JonSkeet answer ---- EDIT Of course I can just access Enabled from the sub class to work around this but can someone explain why this is the behaviour?
bare with me during this silly example. :-) Let's say I have a class like this:
Public Class Animal
Public iLegs as int32 ' Number of legs
Public bWings as Boolean ' Wings? Yes/No
End Class
And another class that inherits the "Animal" class and adds one more property:
Public Class ScaryAnimal
Inherits Animal
Public iScariness as int32 ' 0-100, how scary is it?
End Class
Now, if I have an instance of "Animal" with some values in it, and I decide I want to cast it to a ScaryAnimal for some reason, how do I do that without having to create a new instance of "ScaryAnimal" and copy each property value?Basically I'm looking for a way to do this, without having to write the lines marked with '*** below:
[Code]...
I have a base form and I inherit other forms from it. However, if i go back and change say the size of the base form, I don't see those changes take effect in my inherited forms. Does anyone know why that is? Is there a solution to this issue?So as far as design is goes, what exactly gets inherited by other forms?
View 9 RepliesI have a VB file that imports System.IO, but only uses it is a couple of places.My co-workers and I were wondering if there is a small performance boost if we just use System.IO explicitly were we need it (IE., System.IO.MemoryStream) instead of importing it.
View 2 RepliesI want to pick a value from a DateTimePicker in 'MM/dd/yyyy hh:mm tt' format, add 00 as second with it, store it in a DateTime variable and save it to database. Suppose if I pick the value 05/28/2010 9:25 AM or 05/28/2010 9:25:34 AM from the DateTimePicker, it'll be stored in the variable and saved to database as 05/28/2010 9:25:00 AM irrespective of what value is chosen from the DateTimePicker for second. I'm using the following statement but it's getting failed during the format conversion while storing it in the DateTime variable generating an error.[code]
View 3 RepliesI want to pick a value from a DateTimePicker in 'MM/dd/yyyy hh:mm tt' format, add 00 as second with it, store it in a DateTime variable and save it to database. Suppose if I pick the value 05/28/2010 9:25 AM or 05/28/2010 9:25:34 AM from the DateTimePicker, it'll be stored in the variable and saved to database as 05/28/2010 9:25:00 AM irrespective of what value is chosen from the DateTimePicker for second. I'm using the following statement but it's getting failed during the format conversion while storing it in the DateTime variable generating an error.
[code]...
Public Sub VMClim(ByVal table, ByVal tabname$, ByVal tableno) tabname$ has the error all arguements must be explicitly typed, what does it mean?
View 3 RepliesI have a class clsContextPopUpMenu to create a ContextMenuStrip with some basic functions (e.g.copy) that I can use in different controls. [code] A broader question is that when should I dispose objects/resource by myself? Of course, gc collector is not a magician to release all available memory. Can I always dispose objects/resource in Dispose Sub as shown above?
View 1 RepliesIs there a way to get an enum to explicitly cast to it's base type?If I have something like this:
Code:
Public Enum Packets As Byte
Stuff = &H0
End Enum
I have to do
Code:
Dim test As Byte = CByte(Packets.Stuff)
Rather than
Code:
Dim test As Byte = Packets.Stuff
I don't see why that's the way it works, since you know that the enum will always have values of the base type.
In VBA from Access 2003 I was able to employ the following :Form.Controls(" in here I am able to use a string variable holding the name of the control I want to reference ").property= etc.Is this kind of thing possible in VB .netI have a listview control to which I am adding 'errors' and the tag property of each item hold a string that is the name of the control I want to set the focus to when they double click on the listview item. So I want to do something like this :<listviewitem.tag>.focus()and have the string interpreted as a control name.
View 5 Replieswhen I search for a customer, it can search but the problem is that when I search for customer and I wanted to update or delete, It has an error which says "OleDbCommand.Prepare method requires all parameters to have an explicitly set type." What does that mean? Here is the code that I am using:
Public Class EditingCust
Dim cmd As OleDbCommand
Dim myAdapter As New OleDbDataAdapter[code].....
I'm having some very weird issues with interfaces right now.
I have a very simple setup. In one of my class, I have a Property implementing a Property from an Interface.
In my class it's like:
Private _oForm As IForm
Public Property Form As IForm Implements IContainer.Form
Set(value As IForm)
[Code]...
I have like dozens of interfaces like this working throughout my project and I can't believe this simple one can't work!
on the custom inherited control i created, i noticed that when i bind my custom property to a data column, if that data column returns a value other than Null it always return a datarowstate of modified even if there were no changes. to produce this issue, i have below a sample code for a test inherited control
Imports System.Windows.Forms
Imports System.ComponentModel
Public Class TestControl
[code].....
I am getting an error: OleDbCommand.Prepare method requires all parameters to have an explicitly set type.
on the last line of the code below.I have seen things saying you have to set the datatype of each parameter but how can i do that when it being generated by the command builder?
[Code]...
I have two classes[code]...
How can I modify class1 in a sub in class2?
I am having a problem with closing a form which I have inherited I have a form called frmAddForm_Simple, which contains 4 main controls (A Data Grid, A Save Button, A Close Button and a Text Box). The idea around the form is to create a form which could be used for inputting of many different types of data which are all entered in the same way (i.e. to add a new row to a database for [Status] table or [Location] table, all of which contain 2 columns in the database (an [Id] and a [value]). On the form I have a property called _FormChanged, which when the textbox text changes, sets the property to True. I then have the following code on the Close Button:-
Public Sub btnClose_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnClose.Click
If _FormChanged Then
If MessageBox.Show("Are you sure you want to close and discard any changes?", "Discard Changes",
[CODE]...
Is opened as a dialog (ShowDialog) and when I go to close the inherited form (by click on btnClose) and answer No to the above MessageBox the form closes anyway. Using the Debugged I have worked out that the following events occur in sequence (all of which runs in the Master Form mentioned above):-
1) btnClose_Click sub Routine runs
2) I answer No to the question do I want to close the form
3) The debugger steps over the Me.Close() line (as expected)
4) The debugger jumps up to the Sub Initialise (where ShowDialog was called from) and closes the form.
So at no point has the debugger even ran a line of code which reads Me.Close(), but the form closes anyway so Im fairly confused as to why the form should close.
My Master Form (frmAddForm_Simple) Code:-
Public Class frmAddForm_Simple
Private _FormChanged As Boolean = False
Private _FormLoading As Boolean = False
[CODE].............................
I'm confused regarding the MS examples for inheriting a treenode. I have created the following class to allow an addtion description field on the treenode:-
[Code]...
[code].....
View 1 RepliesI am trying to create an inherited form- when I go to add it, I get the following message- "CustomerInformation --- The base class 'Object' could not be loaded. Ensure the assembly has been referenced and that all projects have been built"
View 3 RepliesI am writing a COM Add-in for Microsoft Access 2010 using Visual Basic 2010.
I do not understand why the members of an inherited interface are not available to VBA. They do not appear in the VBA Object Browser and a run-time error occurs if an attempt is made to use them.
Here is a full code sample which demonstrates the problem:
First I have a base class with a defined interface:
Public Interface IClassBase
Property id As String
Property Name As String
End Interface
[Code]....
When I pass an an object 'MyObject' which implements 'IMyInterface' to a method parameter declared as IMyInterface, I understand that this method parameter 'sees MyObject through the eyes of its interface'.
View 2 Replieson the custom inherited control i created, i noticed that when i bind my custom property to a data column, if that data column returns a value other than Null it always return a datarowstate of modified even if there were no changes.to produce this issue, i have below a sample code for a test inherited control
Imports System.Windows.Forms
Imports System.ComponentModel
Public Class TestControl
[code]....
create a form, add the usual objects necessary for data bindings, (datasource, datatable). make sure the data column bound to this TestControl will return non null values.also create a procedure for position changed to catch the datarowstate like below...
Private Sub PositionChanged(ByVal sender As Object, ByVal e As System.EventArgs)
Dim rowstate As DataRowState = DataRowState.Unchanged
[code]....
Note that i used Position - 1 so that when you go to the next record, it will show you the rowstate of the previous record.
on your Form_Load add the ff:
AddHandler YourBindingSource.PositionChanged, AddressOf PositionChanged
don't make any changes to the current record before you go to the next record. you will see that the rowstate will still return Modified.