PowerShell:Understanding Windows Forms Data Binding 2

Example of a data bound form.

# Set up the form objects and bind$customerBindingSource = New-Object System.Windows.Forms.BindingSource$nav = New-Object System.Windows.Forms.BindingNavigator($true)
$ds = New-Object System.Data.DataSet# configure navigator$formXMLDataBindingExample.Controls.Add($nav)
$nav.BackColor = 'LightBlue'$nav.ShowItemToolTips = $true$nav.Dock = 'top'$nav.BindingSource = $customerBindingSource

That is all it takes to set up a form for data binding.  We create a BindingSource, a BindingNavigator and a DataSet.

The BindingNavigator is optional. I added it to the demo forms to test and show how all controls are synchronized to the DataSet. Ignoring the navigator control we just need two things; a dataset and a binding source.

In the linked example I load the data set from an XML source but this can be loaded from any ADO.Net data provider such as SQLServer, Oracle, MS Access, Excel, CSV or dozens of others.
Once the data is loaded and added to the binding source we can then bind the binding source to any data bindable properties of a control.

 # Set up the form objects and bind
$customerBindingSource = New-Object System.Windows.Forms.BindingSource
$ds = New-Object System.Data.DataSet

Create the basic objects then load the dataset.

    $ds.ReadXml($northwindXml)

All we have left to do is to connect the binding source to the control.
In the demo code, I embed the binding into s single line.  Here is the breakdown.

$binding = New-Object System.Windows.Forms.Binding(
    'Text', 
    $customerBindingSource, 
    'ContactName', 
    $true
)
$textboxContactName.DataBindings.Add($binding)

See: System.Windows.Forms.Binding

The ‘Text” argument is the name of the property to bind to.  Next, we use the binding source object and then the name of the field in the dataset.  Last, we can add 4true/$false to choose whether or no to enable the formatting of the control.

Note that this control has a “bindings” collection.  We can add multiple bindings to the control bound between different data sets and properties.  This is a very powerful capability allow s to define forms in a database and auto-generate the forms at runtime.  For our basic forms, we will not explore this but it is nice to know.

Now go back and look at the project form and see how this is done and how we only need to assign each control to a property in the binding source and the controls will all be synchronized to each otter and to the record movements in the dataset.  We can move, filter and search with almost no code.

In the next post I will discuss how this can be used in some practical applications and the implications of data binding for automation of nearly all aspects of a form.

Posts in this article:

PowerShell: Understanding Windows Forms Data Binding
PowerShell:Understanding Windows Forms Data Binding 2

Extra
Binding SQlServer Data to WinForms with PowerShell