I have two nested objects, and the form has two ListBoxes, where I want the last to respond to the selection of the former. It can even be some times deeper than 2 levels, which can make it a bit cumbersome. I solve it by raising events in any method that makes an add/delete/rename of these objects, and the form listens for these events, and when fired, clears it's lists, and loops through these objects to populate the lists again. binding lists, but this seems to introduce a few issues. First I need to keep a set of extra lists in the main BLL class, but more importantly, I feel I'm violating the layered structure between the BLL and the form, as in this case, the BLL needs to keep track of the current selected indexes of the listboxes in some variable. So that doesn't feel right, as it makes the BLL vulnerable to what the form does, and I assume is simply principally incorrect.
Following is example of object structure, where two ListBoxes should display "Company Names" and "Employee Names", and the Employee name listbox obviously change according to the selection in the Company Name listbox.
Public Class Form1
private _main as New Main
...
End Class
I'm new to WPF and databinding. I need to bind expander header to a List(Of Names) and expander content to a List(Of Services). I'm even more confused after reading MS tutorials on databindings (how and where to use staticResource, Path, etc.)
[Code]...
How do I bind header textblock to the person name and the inner listbox item to their services ?
I have a nested class, let's call it class1 and it has class2 inside it; VB.Net eg:[code]
1) How can I define X number of Class2 objects[let's call it: Node(x) array]** with NEW() subroutine called?' this raises error: dim cls2(n) as new class2 end sub.
2) How can I return actual number of Node() array? [code]Outside my class in main project I define cls1 object:[code]Now an array of class2 is created inside cls1.
3) Now,How can I access All of them[node(x) array which is created inside cls1] with all properties and methods available?
I remember I wrote a ProcessManager class with this functionality in .net 2003, nearly 4 years age, I don't have the code now.
I can't seem to find a lot on how to use events in nested objects. I suspect that I should have access to the events in the nested objects through intellisense if I had done things right. I have many objects with 50 or so properties and I would like to access them with out adding handlers for each one and additional events in parent objects.
Example: Public Class Form1 Dim WithEvents myCombinedClass As New CombinedClass
I'm struggling to implement a maybe monad - which I've called Nullable in this example.
The Nullable Class is implemented as follows: Public NotInheritable Class Nullable(Of TClass)
Private _value As TClass Private _hasValue As Boolean Public Shared Function Create(ByVal value As TClass) As Nullable(Of TClass) Return New Nullable(Of TClass)(value) End Function
[Code]...
The way the monad is implemented at the moment I would need to issue the following to access a property on the nested child class dim id = MyParentClass.ChildClass.Value.ID
but ideally what I'd like to be able to do is to have the following statement dim id = MyParentClass.ChildClass.Id and if the ChildClass is null then just return a default value for the property type.
I tried implementing this using Default Properties and setting the Value as default via an attribute but it wouldn't compile. Is that going to be possible or perhaps there is a better way of architecting it - or maybe I just haven't 'got' the maybe monad?
I don't know if this is even the correct terminology but I was wondering if it is possible to bind a row (of data) from a database to an object. I am working on a school project and we have decided to create this application to track a user's BMI/BMR and compare it to the amount of calories they have input. The program doesn't go too in depth so it does not store the calories consumed in the database.
So here is my problem. I have a row in my database:
And I guess what I am thinking I want my program to do is if I have an object with properties for FirstName, LastName, HeightInches, WeightPounds, is to somehow query the database for one row and put the values into the object. All we have learned so far is binding the data with controls which doesn't really help in my case since the work is going to be done behind the scenes.
i created a class i invoke the class as object in vb.forms i want bind object(parameters) to datagrid when return as arraylist from methods in form_load. i want to bind arraylist to datagird in form_load.it will bind, the grid show all the parameter from arraylist.but i want few columns to bind from arrylist.here arraylist is convert from list from method.
I have an RDLC report that I am rendering directly to the Response Stream as PDF (rather than using the ReportViewer). In the code that renders the report, it's DataSource is bound to a List(Of ClassA) objects defined in a custom assembly. This seems to work for the most part. My problem is that I can't seem to handle the situation where a nested object is null. For example, given ClassA and ClassB (the nested object) defined as follows:
Public Class ClassA Public Id As Integer Public Name As String
[Code]....
the report displays "#Error" if TheNestedObject is null. If TheNestedObject is not null, it correctly displays the Name.
I have a ListView bound to an ObservableCollection of CustomerContacts.It works great so far, but being new to this, I'm not sure how to do the next part.Each customer contact has several contact types, which I want to display under their name.
So inside of CustomerContacts I have another ObservableCollection of ContactTypes. Here is my current datatemplate: <DataTemplate x:Key="iconTemplate">
I'm trying to bind a WinForms TreeView control to some user-defined objects. In particular, I'd like to bind aTreeNode.Text property to myObject.Name. My strategy is to create xTreeNode, a subclass of TreeNode, add a DataBindings collection, and expose its Text property. This would allow me to write some code like this:
Dim oBinding as Binding Dim bs as New BindingSource bs.DataSource = myObj
I am using a loop to update properties of each object of a set of custom objects. The routine knows which controls to update because the controls value is not empty, I don't want the routine setting the corresponding properties to nothing when the control is empty. Now I know how to do this perfectly fine with IF statements such as:
CODE:
But this feels really redundant doing that same IF block over and over for each property/control combination, I thought about creating a separate routine that takes the control as an argument and does all the repetitive IF blocks but I don't know how I could also pass an object property to tell the routine to update that particular property.
I have a form called studentForm which has a studentCombobox, studentTextbox and a studentDatagridView
In the constructor of the studentForm I need to bind studentCombobox to the StudentbindingSource of the main form and to bind studentDataGridView to appropriate binding source in the mainForm.So that this datagrid view displays all the bookings for the studentID currently selected in studentComboBox
code For Each item As Reflection.FieldInfo In GetType(NameSpace.ClassWithNestedClasses).GetFields rtfAppend(item.Name & ":" & Tab & item.GetValue(Me)) Next For Each item As Reflection.PropertyInfo In GetType(NameSpace.ClassWithNestedClasses).GetProperties()
[code]...
which gets me the simple string vars and properties of my top class, but how can i apply this to loop through all sub classes and get there vars and props?
I am trying to bind my SQL param's qurey to bind to a table. My problem is i get this error "Fill: SelectCommand.Connection property has not been initialized."
Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles Button1.Click If RadioButton3.Checked = True Then Dim connectionGrid As SqlConnection = New SqlConnection("Data Source=BST;Initial Catalog=dsfs;uid=dfsdf; pwd='dsfsf'") Dim commandgrid As SqlCommand = New SqlCommand()
I am getting this error, Not sure why it is happening "Error The SqlParameterCollection only accepts non-null SqlParameter type objects, not Int32 objects."I have tried with all sorts of possibilties, now try to enter default data as dummy data,
Using connection As New SqlConnection connection.ConnectionString = ConfigurationManager.ConnectionStrings("DentalDeviceConnectionString").ConnectionString connection.Open()[code].....
I want to let the user input objects to a richtextbox 1 object on each line, and somehow use Random.Next to select pseudorandomly a few objects, the number 'few' inputted in a textbox.
Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Using conn As New SqlConnection("Database=Clinic_Management_System;Data Source=.SQLExpress;Integrated Security=True;AttachDBFilename=|DataDirectory|Clinic Management System.mdf") Dim cmdRecord As SqlCommand
I have a user control that inherits the FW ListView and I need to dispose of two objects when the form's disposing of it's objects. Here's what I've concluded already, am I on the right track?
I'm currently developing an application with a reasonably complex DataGridView that allows the user to build the lines of a sales document: Quantitiy, Description, Price, etc with some additional fields to help calculate price based on cost or discount i'm sure you get the jist - all this means we're not just diplaying data but adding and manipulating it - It also means there's mainly decimal fields, nit just simple text fields
Now, i'm new to VB.net, so i've perhaps done things a bit backwards during my learning curve, namely designing and coding my DGV before creating the underlying database table and binding to it - so as i'm sure you can image there's a bit recoding to do to allow for the fact that it's now bound to a datasource.
I'd got the DGV working just how a wanted it to, but now that i've bound it to a datasource i'm hiting multiple problems with: Formating the appearance of figures in the DGV Problems with blank fields while enering data (before the i try to save the data back to the database) How the DGV is functioning - it seems to behave differently when adding lines to a new sales document than it does when adding lines to an existing sales document
And given that when saving edits to an existing line i need to provide a valid update command i'm begining to think that it might be easier to scrap the databinding altogether and just Select, Add and Edit the database with code rather than binding the DGV in the IDE
I've read various threads about avoiding databinding due to it's limitations, but i've also read that it's far better in later versions of Visual Studio and .net. and i'm using VS2010
I'd just like some advise as to whether my gut feeling is right or whether i should persevere with databinding the DGV. i've noticed some quirks of databinding while working with other controls such as text and combo boxes, but i've overcome these and the result seems to be easier than coding the data transfer manually.
But i'm really struggling with databinding the DGV and the fact that i'm dtatbinding to a seperate table to the rest of the controls is leaning me away from databinding
long story short, I have created a ListView type control, using UserControls for the parent control and the ListViewItems. Most the of the control is written and works fine, right up to the point where I tried to replicate the 'Control.SelectedItems(0).Index' property and the 'SelectedIndexChanged' event.
Each child object knows its index value, and could pass this value via the SelectedIndexChanged event (assuming this is how it works in a normal ListView control -- user clicks on an item, and that item fires an event updating the selected index value in the parent object).
How does the child object raise an event in the parent object? I have a feeling this could be done with Delegates, but I'm still learning about their usage.
I want to compare two objects to check if all the properites of both the object have same value or not. for this i need to use the reflection to enumarate through all the properties of an object and check the value of the property. To try the code just i have written a Employee Class having Two Properties EmployeeNo and EmployeeName. I am creating an object of the Employee class and need to write a function that can list the values of all the properties in the class.
