Add new row into `DataGridView` and enter data from `TableAdapter` in another form - vb.net

Question

I am trying to add new row of data in the DataGridView that is located in Form4. The data is to be entered in the Form3 into TableAdapter that is bound with DataGridView.
On the Form4 I have a button that opens Form3 and it suppose to add new rows into DatagridView but seems like it is not doing it.
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles
Button1.Click
Form3.Show()
Form4.DbTableDataGridView.Rows.Add() 'this is not executed?
End Sub
On the Form3 there is a TableAdapter that suppose to fill in new added rows in the DbTableDataGridView and then saves the changes. Something like:
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Form4.DbTableDataGridView.Rows.Add(Me.DbTableTableAdapter)
End Sub

Answer 1

This works fine.
Public Class Form4
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Form3.ShowDialog()
End Sub
End Class
Public Class Form3
Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
Form4.DataGridView1.Rows.Add("Add Something here")
End Sub
End Class
Does the data in your datagridview is from database?
You can have a Public Sub in your Form4 to show the records.
Example:
Dim cn As New SqlConnection("your connection string here")
Dim cmd As New SqlCommand
Dim da As New SqlDataAdapter
Dim dt As New DataTable
Public Sub ShowRecord()
cn.Open()
With cmd
.Connection = cn
.CommandText = "Your command text here"
End With
da.SelectCommand = cmd
dt.Clear()
da.Fill(dt)
dataGridView1.DataSource = dt
cn.Close()
End Sub
In your Form3:
you can save the data in the database then call the sub in form4 like
form4.ShowRecord()
This is just a simple example though