No PowerShell Form datagrid selected - powershell

Question

I have created a script that must select all the items in a powershell form, based on a variable. If the variable $bolCheckAllNumberedItems has the value '$False, then the grid should not be selected, in case the variable $bolCheckAllNumberedItems has the value '$True', the whole grid should be selected.
The code I have:
Clear-Host
$bolCheckAllNumberedItems = $True
$frmTest = New-Object 'System.Windows.Forms.Form'
$btnOk = New-Object 'System.Windows.Forms.Button'
$chkAllItems = New-Object 'System.Windows.Forms.CheckBox'
$DataGridForTest = New-Object 'System.Windows.Forms.DataGridView'
$InitialFormWindowState = New-Object 'System.Windows.Forms.FormWindowState'
$frmTest.Controls.Add($btnOk)
$frmTest.Controls.Add($chkAllItems)
$frmTest.Controls.Add($DataGridForTest)
$frmTest.AutoScaleDimensions = New-Object System.Drawing.SizeF(6, 13)
$frmTest.AutoScaleMode = 'Font'
$frmTest.ClientSize = New-Object System.Drawing.Size(284, 261)
$frmTest.Name = 'frmTest'
$frmTest.StartPosition = 'CenterScreen'
$frmTest.Text = 'Test'
#
# btnOk
#
$btnOk.Location = New-Object System.Drawing.Point(186, 220)
$btnOk.Name = 'btnOk'
$btnOk.Size = New-Object System.Drawing.Size(75, 23)
$btnOk.TabIndex = 1
$btnOk.Text = '&Ok'
$btnOk.UseVisualStyleBackColor = $True
$btnOk.add_Click($btnOk_Click)
#
# chkAllItems
#
$chkAllItems.Location = New-Object System.Drawing.Point(22, 22)
$chkAllItems.Name = 'chkAllItems'
$chkAllItems.Size = New-Object System.Drawing.Size(104, 24)
$chkAllItems.TabIndex = 1
$chkAllItems.Text = 'Select all items'
$chkAllItems.UseVisualStyleBackColor = $True
$chkAllItems.add_CheckedChanged($chkAllItems_CheckedChanged)
#
# DataGridForTest
#
$DataGridForTest.ColumnHeadersHeightSizeMode = 'AutoSize'
$DataGridForTest.Location = New-Object System.Drawing.Point(22, 52)
$DataGridForTest.Name = 'DataGridForTest'
$DataGridForTest.Size = New-Object System.Drawing.Size(240, 150)
$DataGridForTest.TabIndex = 0
$DataGridForTest.TabStop = $False
$DataGridForTest.ColumnCount = 1
$DataGridForTest.ColumnHeadersVisible = $true
$DataGridForTest.Columns[0].Name = "Number"
$DataGridForTest.Columns[0].width = 100
$DataGridForTest.ScrollBars = 'Vertical'
$DataGridForTest.ReadOnly = $True
$DataGridForTest.AllowUserToAddRows = $False
$DataGridForTest.AllowUserToDeleteRows = $False
$DataGridForTest.AllowUserToResizeColumns = $False
$DataGridForTest.AllowUserToResizeRows = $False
$DataGridForTest.SelectionMode = "FullRowSelect"
$DataGridForTest.MultiSelect = $true
#----------------------------------------------
$ArrayNumbers = #("one","two","three","for","five","six","seven","eight","nine","ten")
[system.collections.arraylist]$ArrayWithHeader = #()
ForEach ($object in $ArrayNumbers)
{
$value = [pscustomobject]#{'Number' = $object}
$ArrayWithHeader.Add($value) | Out-Null
$value = $null
}
$ArrayWithHeader | foreach {$DataGridForTest.Rows.Add($_."Number") | Out-Null }
if($bolCheckAllNumberedItems)
{
$chkAllItems.Checked = $true
$DataGridForTest.SelectAll()
}
$chkAllItems.Add_Click({
if($chkAllItems.Checked)
{
$DataGridForTest.SelectAll()
}
else
{
$DataGridForTest.ClearSelection()
}
})
$btnOk.add_Click({$frmTest.Close()})
[void]$frmTest.ShowDialog()
What is wrong with my code? Help is appreciated and with kind regards,
The Sting Pilot

Answer 1

I think the easiest way of doing this is to start your script with a small function you can call inside the checkbox Click() event aswell as in an added form event called Add_Shown()
function Select-Grid ([bool]$selectAll) {
$chkAllItems.Checked = $selectAll
if ($selectAll) {
$DataGridForTest.SelectAll()
}
else {
$DataGridForTest.ClearSelection()
}
}
This way you can remove these lines:
if($bolCheckAllNumberedItems)
{
$chkAllItems.Checked = $true
$DataGridForTest.SelectAll()
}
and instead write
# call the helper function with the Checked value of the $chkAllItems checkbox
$chkAllItems.Add_Click({ Select-Grid $chkAllItems.Checked })
# this is an added event that fires when the form is first shown
$frmTest.Add_Shown( { Select-Grid $bolCheckAllNumberedItems } )
[void]$frmTest.ShowDialog()
# very important! dispose of the form when you are finished with it
$frmTest.Dispose()
An alternative approach is to again remove these lines:
if($bolCheckAllNumberedItems)
{
$chkAllItems.Checked = $true
$DataGridForTest.SelectAll()
}
and change the event $chkAllItems.Add_Click() to use a different event:
$chkAllItems.Add_CheckedChanged({
if($chkAllItems.Checked) {
$DataGridForTest.SelectAll()
}
else {
$DataGridForTest.ClearSelection()
}
})
Activate that event when the form is first shown and finish the code:
$frmTest.Add_Shown( { $chkAllItems.Checked = $bolCheckAllNumberedItems } )
[void]$frmTest.ShowDialog()
# and not forget to get rid of the form from memory
$frmTest.Dispose()
Using the CheckedChanged() method does not need an extra helper function as with the first approach.