Passing parameters between two forms in VB.Net - vb.net

Question

I currently have about 5 forms in my application. I'm building a 6th form - frmSummary however, I'd like to be able to access it from all forms. in frmSummary I am planning to add a DataGridView, where I'll be displaying data related to that form. I'm thinking that I should either create a global variable such as
dim FrmName as String
In each form I would have a cmdSummary button so that On click_event, I would do something like
frmName ="CustomerInfo"
Currently the way my application is set up is that I hve a mdiForm and within it, each form is a child so on opening new forms I do something like...
Private Sub cmdSummary_Click(sender As Object, e As EventArgs) Handles cmdSummary.Click
Dim NewMDIChild As New frmClientEligibilityReferral()
frmName = "CustomerInfo" --since this will be comeing from frmCustomerInfo
NewMDIChild.MdiParent = MDIform1
NewMDIChild.Show()
MDIForm1.Show()
End Sub
So I do something like that on opening my new form. My question is how can I pass the parameter to my form frmSummary....here's currently what I'm trying to accomplish....
Private Sub FrmSummary_Load(sender As Object, e As EventArgs) Handles Me.Load
Me.MdiParent = MDIForm1
InitializeComponent()
'Here I want to call a function to load the datagridView(with g_frmName)see below...
call LoadDataGrid(frmName)
End Sub
Is something like that a smart idea? Or should I/Can I directly call the function from the previous form?
Just trying to see if I'm on the right track, if not, how can i do it in a sound way?

Answer 1

If there is only one frmSummary, you could make it a singleton.
In frmSummary, put the following code:
Private Shared _instance As frmSummary
Private Sub New()
' This call is required by the designer.
InitializeComponent()
' Add any initialization after the InitializeComponent() call.
End Sub
Public Shared Function GetInstance() As frmSummary
If _instance Is Nothing Then
_instance = New frmSummary()
End If
Return _instance
End Function
Public Sub PutDataInGrid(data As Object)
Me.DataGridView1.' put data in it
End Sub
And you would access it from other forms like this
Dim myFrmSummary = frmSummary.GetInstance()
myFrmSummary.PutDataInGrid(myData)

Answer 2

If I understand the question correctly....
You can just set the required parameters in the New declaration sub (Where InitializeComponent() is supposed to be). On your form, declare variables and set one to each of the parameter values, and set up your form this way..
An example might be;
Public Class frmSummary
Dim var1 as String = ""
Dim var2 as Boolean = True
Public Sub New(ByVal parameter1 as String, ByVal parameter2 As Boolean)
var1 = parameter1
var2 = parameter2
InitializeComponent()
End Sub
Private Sub frmSummary_Load(sender as Object, e As EventArgs) Handles MyBase.Load
If var1 = "This String" Then
If var2 = False Then
sql = "SELECT * FROM myTable"
' Rest of your code to get the DGV data
DataGridView1.DataSource = Dt
Else
End If
End If
End Sub
Again, I may have misunderstood the question, so apologies if that is the case.