'This code usualy works when placed within the forms code, however I am wanting to create a class with several text manipulators. The error says System.windows.Controls is not defined
Imports System.Object
Imports System.Windows.Forms.Form[code].....
In my code I use two classes. One contains the UI form, the other containsa method to write to a file. During coding I found out some behaviourwhich I don't understand. The code below shows (what I believe to be)the relevant part. The file writing part is substituted by a MsgBox for simplicity.I have the following controls in one form:
NumericUpDown
Button
With the following classes and methods:
[code].....
i am building a tab control (using VS 2010 and 4.0 framework). on Tab 0, this works as expected:
Me.ddUE_B1.SelectedValue = Me.B1.Text <-- changes the combo box selection to what is in the label.
on the other tabs this does not work. when I do a messagebox to show, say, Me.Ea1.Text on Tab 1, nothing is returned.
Is there an issue with referencing controls on tabs that I am missing? In general, I will need to set combo box's value to what is in the database when the form loads.
String s = "test"; String is a class, so to use it we should create an object of it. But rather we just make a reference of it and give it a value. How is it possible and what concepts are used in it. The metadata of String class shows the following :
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I was create Access database with Access 2003. I create VB project with Visual Studio 2005 Standard With connection wizzard I create coonect with this Access database, select all tablesI see this database inside Data sources and inside Server explorer Test connection is OK When I drag and drop table from Data sources, Wizzard don't create DataGridView, DataSourceBinding etc .. and I see popup window with mesage: Object reference not set to an instance of an object and then "game over"
View 2 Repliesso I have a generic list in a console application. Dim Channels as New List(Of Chatroom) Chatroom is a structure. But I have multiple classes, threads, and timers looping through this list, sometimes at the same time, but it always seems to raise errors because the number of items in the list gets changed while one of the other classes/threads/timers are looping through also. Is there any way to allow only one to manipulate it at a time?
View 8 Repliesit is possible to create a class based on text box, add some code to its events, say gotfocus event, and visually add this textbox to a form instead of adding it in code. Just like we drag and drop a textbox to a form from toolbox.
View 5 Repliesmy proble is the following: I have a class MyClass and another class Modifier, which has a method ModifyMyClass(ByRef mc as MyClass) that receives a MyClass instance as ByRef parameter to modify it. A smell of the code is:
[Code]...
I have a 'property management class' that contains several functions and properties. I have several other classes that use the 'management class' as a property to derive the value of several of its other properties.Is there a way for me to reference the outer class from the 'management class' functions without having to pass it as a parameter? I ask because several different classes can have this 'management class' as a property and am having a hard time typing the parameter.
View 7 RepliesI have a class in which some of the fields are also classes.I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition
dados_Defenicao.arCode = "123"
dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
How can i fix this ?
I have a class in which some of the fields are also classes.
I can put values in the "normal" properties, but in the others when o try to assign values it gives the: "Object reference not set to an instance of an object"
But the code compiles fine.
dados_Defenicao = New ServiceReference1.draftClaimEntryDefinition
dados_Defenicao.arCode = "123"
dados_Defenicao.claimMarket.warrantyType = "w" - Here it gives the error
If we are within the derived class then ofcource we can use MyBase keyword to access base class's object reference . That's fine , how can we take that base class's object reference outside that derived class's definition.My following code will explain what i want . Actually that is giving error right now, but it is explaining my requirement .
Public Class Base
Public x As String
End Class
[code]....
Actually there is error in ReadOnly Property BaseReference's Getter . Error is "Error 1 'MyBase' must be followed by '.' and an identifier. " how can i get base class object reference in Main method ?
I have a Parent Class Called Fuselage that containsfour child classes called Forebody, CenterBody, AftBody, and CrossSection. CrossSection classcontains objects common to Forebody, CenterBody, and Aftbody (example: width). How do I access thewidth property in CrossSection from within the classForebody?
Public Class Fuselage
Dim Forebody As ClsSection
Dim Centerbody As ClsSection
[code].....
I need to create a new instance of a class that needs a member of the calling class. But i can't pass a reference to the calling class through the constructor.The solution i am looking for is something like this:
Public Class ChildClass
Public Sub New(args)
_MyMember = GetMemberFromCallingClass()
[code]....
I want this to work without having to manually pass any references or variables from the calling class to the new instance of ChildClass.
Is there a way to iteratively reference an ASP.NET control based on it's name pattern? Perhaps by a "pointer" or something?What I have are a large set of comboboxes (each with an associated DropDownList and TextBox control). The DropDownList always has an item selected by default, but the use may wish to submit a NULL value. I come up with the following code to handle three cases: NULL, Existing Item, New Item.
'TextBoxControl & DropDownListControl should iteratively reference their
' respective TextBox & DropDownList controls by the actual control name
[code]....
The problem is, with so many comboboxes, I could easily end up with hundreds of lines of code. I wish to handle this in a more dynamic way, but I do not know if it is possible to reference controls in this way. Say I wanted to reference all the TextBox Controls and DropDownList Controls, respectively.
I can do string formatting with a given naming pattern to generate a name ID for any of the controls because they are all named with the same pattern. For example by attaching a specific suffix, say "_tb" for TextBox Controls and "_ddl" for DropDownList Controls:
Left(item.SelectedItem.ToString, item.SelectedItem.ToString.Length - 3) + "_tb"
Can this sort of thing be done in VB? Ultimately, my goal is to take the value entered/selected by the user, if any, and send it to a stored procedure on SQL Server for insertion into the database.
I am writing a simple control translation function that reads an XML file containing control names and their localized text. Within the application, each time a form is loaded, it iterates through every control and tests to see if that control is defined in the XML file. If it is, it then sets the control text to whatever localized text is defined in the XML file.
There are some tests and additional requirements (i.e. nested loops) for TabControl and MenuStrip etc., but the control that is giving me the most trouble is the ContextMenuStrip.[code]...
I currently do all development work in VB.NET 2008, winforms; but within 18 months will be switching to WPF (for better or worse). I have had great success using Matthew MacDonald's "Pro NET 2.0 Windows Forms and Custom Controls in VB 2005" book. This is an excellent reference focused entirely on the development of custom controls in windows forms. ( Many of the controls that I use have to have a very specific UI look and feel, so they end up being custom.
I'm looking for pretty much the exact same thing, except focused on WPF. MacDonald has a new book coming out on WPF in general ,but not on custom controls. Books are my preferred reference material, but any good web references.
I was trying to make my program see if facebook.com was running in internet explorer.
I added the following
Private Function isFaceBookOpen() As Boolean
For Each ie As SHDocVw.InternetExplorer In New SHDocVw.ShellWindows()
Dim filename As String = System.IO.Path.GetFileNameWithoutExtension(ie.FullName).ToLower()
If filename = "iexplore" Then
[code]...
And added reference; Microsoft Internet Controls (COM tab) but i also need to add this reference; Microsoft.mshtml (.NET tab)
Problem is that i can't find that reference. BTW, I want the function to be triggered by a timer.
I'm wondering about a feature in Visual Studio. Personally it bugs me when I open a solution someone else has been working on and it's full of Controls with Ids like "label27" "textbox3" etc. One of the first things I do is either rename them or remove them if they are never referenced in code behind (as is usually the case with the labels).
[Code]...
Having:
<asp:FormView ID="frmEmployee" runat="server">
<EditTemplate>
<asp:TextBox ID="txtFirstName" runat="server" />
[code]....
is there a way to reference this control statically, without having to use FindControl?
VB.Net
txtFirstName.Text = "George"
C#
txtFirstName.Text = "George";
This code passes a button name ("Button2") and a value (4) to be displayed on it. Can the "UpdateButtonName" procedure be streamlined by replacing the "For Next" and "If Endif" code with something else since the button name is already known? It shouldn't have to check control on the form to see if it is the one I want.
Public Class Form1
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
[Code].....
I have a user control that I'm adding to a webpage dynamically. The ascx has a couple of controls that I want to have access to at runtime. I can access the ascx itself, but none of the controls on the ascx are available. I have tried adding a simple public variable and also tried adding a public property to the ascx, but I am unable to get access to either of them at design time (compile errors). I added the following to the code-behind of the ascx control:
Public Property areaCode() As String
Get
Return iebEmpPhoneAreacode.Text
End Get
[code]....
The book "Beginning ASP .NET 4 in VB 2010" contains the following:NOTE: TaxableProduct inherits from Product.You can also cast in the reverse directionfor example, cast a Productreference to a TaxableProduct reference. The trick here is that this
View 2 RepliesI've created some dynamic controls on page load and added an event handler to handle the click event of a dynamic link button. Within the sub of the click event handler, I need to reference some other (non-dynamic) controls on the page and change their value. However, I get a null reference exception - object not set to an instance of an object - each time I try to reference a control on the page (in this case label1). What am I doing wrong in creating these dynamic controls or with my event handler?
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
'Get the data to populate the controls
[Code]....
Currently, when I want to use Microsoft Chart Controls on a website, I need to add the following onto every aspx page where I want to use it:
[Code]...
Is there any way to move this to the web.config file, so that I don't have to put it on every page ?
I am trying to create a log file which I am going to use to populate some controls (DataGridView or Treeview). I am trying to figure out if should use text files or XML files to do so. Effectively the log will highlight multiple phases in a client-side app. The log will be written to at various phases when the project is running. The user will always have the options move on to the next phase or save progress and exit the project. As such, I want the log file to highlight how far the user has progressed throught the various phases AND I want the log to highlight varous information from each phase. Whenever the user starts the project, they will be given the option to load existing log files. So the project will have to read these log files and append them where necessary as the user progresses.
I am not sure what the best way to do this is and below is a rudimentary approach using text files. As you can see, the top of the file would have a summary of all the phases and whether or not the user completed each phase. Next each phase would have a data section highlighting what data was stored along the way. I have used a ":" to denote each section. Then within each section I would obviously need to use a delimeter for all my data. So if Phase1 = True, then I would load all the pertinent data from "Phase1:" into the desired control. Can anyone provide an efficient way of doing this and provide some insight as to whether I should use XML instead. The phases my change during development and I am not sure yet which controls I will be using. Does XML provide more flexibility.
In summary I am looking to create, read/write and append log files and populate controls with the data in varous sections of the log file. Example:
Phase1 = True
Phase2 = True
Phase3 = False
Phase4 = False
[code]....
I've been creating short test apps repeatedly to try to understand some of the concepts in VB.NET.For the most part it has been illuminating.I read Bucky's .NET knowlegebase tutorial on passing objects as parameters to newly created forms. He shows how to create a new class that inherits from the base form class and define a New() method with parameters Extending the concept I thought about doing the same thing with a form that was created at design-time (In this case Form2).
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I want to read a number of items from a file and then associate each of those items with a new button at run-time, so that when the user clicks one of the buttons I can display some information about that item.Can I use a LIST to manage these buttons and items? Can I create a new class and have each list item of that class, such as 'btnID', 'btnText', etc... ?
View 2 Replieshow can I add a class of a different project to my current project as a reference?I tried Right click_-> add existing item --> ( The class from the other project) then it gives me error.I am not sure how can I use that class as my reference to my current project?
View 3 RepliesI'm converting a VB6 app to vb.net.The code creates objects using the CallbyName function with the classes name & and method being read from a database.I want to rewrite the classes in vb.net and have the same behaviour as I read in the name of an object from the database, instantiate it, and call one of it's methods.I don't know ahead of time what the names of the classes will be, so I can't make a reference to them in my project.
View 1 Replies