MDI parent form toolstrip button control MDI child

Question

I want to make the toolstrip button on MDI parent to be able perform MySQL command for MDI child

I have try to create button in MDI child with an MySQL command and try to access from MDI parent toolstrip event handler using mdiform.button.PerformClick but not successful

Answer 1

From the ToolStrip Button handler, you can check the type of ActiveMdiChild to make sure it is the correct type of MdiChild form, then cast it and tell the button to click itself.

For instance, my MdiParent is Form1, and the MdiChild is Form2:

Public Class Form1

    Private Sub Form1_Load(sender As Object, e As EventArgs) Handles MyBase.Load
        Dim f2 As New Form2
        f2.MdiParent = Me
        f2.Show()

        Dim f3 As New Form3
        f3.MdiParent = Me
        f3.Show()
    End Sub

    Private Sub ToolStripButton1_Click(sender As Object, e As EventArgs) Handles ToolStripButton1.Click
        Dim frm As Form = Me.ActiveMdiChild
        If Not IsNothing(frm) AndAlso TypeOf frm Is Form2 Then
            Dim childF2 As Form2 = DirectCast(frm, Form2)
            childF2.Button1.PerformClick()
        End If
    End Sub

End Class

Public Class Form2

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        MessageBox.Show("Hello World!")
    End Sub

End Class

Here it is running. Note how the ToolStrip button only works if the Active MdiChild is of type Form2, and not Form3: