在DataGridView中移动行时出现间歇性的意外结果

Question

根据我的代码，我有一个基本脚本。因此，这样做的目的是能够在按下向上或向下按钮时上下移动记录。这在某些时候有效，但是间歇性地它不会移动记录（但是所选行仍会移动）。请尝试我的代码，并将第一条记录上下移动几次，希望您很快就会明白我的意思。

谢谢

亚当

[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Drawing") 
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Windows.Forms")
[void] [System.Reflection.Assembly]::LoadWithPartialName("System.Data")

# Main Form
$Form = New-Object System.Windows.Forms.Form    
$Form.Size = New-Object System.Drawing.Size(510,450)
$Form.Text = "Test"
$Form.TopMost = $false
$Form.MinimizeBox = $false
$Form.MaximizeBox = $false
$Form.StartPosition = "CenterScreen"
$Form.FormBorderStyle = "FixedToolWindow"

# Datasource
$dt = New-Object System.Data.DataTable
[void]$dt.Columns.Add("Name")
[void]$dt.Columns.Add("Step")
[void]$dt.Rows.Add("Jack","1")
[void]$dt.Rows.Add("Jayden","2")
[void]$dt.Rows.Add("Dylan","3")
[void]$dt.Rows.Add("Ben","4")

# Datagridview
$DataGrid = New-Object System.Windows.Forms.DataGridView
$DataGrid.Location = New-Object System.Drawing.Size(10,10)
$DataGrid.Size = New-Object System.Drawing.Size(300,200)
$DataGrid.AllowUserToAddRows = $false
$DataGrid.DataSource = $dt
$DataGrid.DataBindings.DefaultDataSourceUpdateMode = 'OnPropertyChanged'
$DataGrid.AutoResizeColumns()
$Form.Controls.Add($DataGrid)

# Up Button
$upButton = New-Object System.Windows.Forms.Button
$upButton.Location = New-Object System.Drawing.Size(320,20)
$upButton.Size = New-Object System.Drawing.Size(90,40)
$upButton.Text = “Up”
$upButton.Add_Click({
    moveRow -1
})
$Form.Controls.Add($upButton)

# Down Button
$downButton = New-Object System.Windows.Forms.Button
$downButton.Location = New-Object System.Drawing.Size(320,70)
$downButton.Size = New-Object System.Drawing.Size(90,40)
$downButton.Text = “Down”
$downButton.Add_Click({
    moveRow 1
})
$Form.Controls.Add($downButton)

# Function to move record in DataGridView
function moveRow ($direction){

    if ($DataGrid.SelectedRows[0] -ne $null){

        $currentRow = $DataGrid.SelectedRows[0].Index

        # Don't move up if you are at the top
        if (($currentRow -eq 0) -and ($direction -eq -1)){
            return
        }
        # Don't move down if you are at the bottom
        elseif (($currentRow -eq ($DataGrid.Rows.Count - 1)) -and ($direction -eq 1)){
            return
        }
        else {

            # Get Current and New Values
            $currentValue = $DataGrid.Rows[$currentRow].Cells["Step"].Value
            $newRow = $currentRow + $direction
            $newValue = $DataGrid.Rows[$newRow].Cells["Step"].Value

            # Swap Values
            $DataGrid.Rows[$currentRow].Cells["Step"].Value = $newValue
            $DataGrid.Rows[$newRow].Cells["Step"].Value = $currentValue

            # Sort and refresh DataGridView        
            $DataGrid.ClearSelection()
            $DataGrid.Rows[$newRow].Selected = $true;
            $DataGrid.Sort($DataGrid.Columns["Step"], "Ascending")
        }
    }   
}

# Show Form
$Form.Add_Shown({$Form.Activate()})
[void] $Form.ShowDialog()