frmCapture

Public Class frmCapture

    Dim Screenshot As Bitmap
    Dim StartPoint As Point
    Dim EndPoint As Point
    Dim CapRect As Rectangle

    Private Sub frmCapture_Load(sender As System.Object, e As System.EventArgs) Handles MyBase.Load
        Me.Visible = False
        Dim Scr As Rectangle = Screen.PrimaryScreen.Bounds
        Screenshot = New Bitmap(Scr.Width, Scr.Height)
        Dim G As Graphics = Graphics.FromImage(Screenshot)
        G.CopyFromScreen(Scr.X, Scr.Y, 0, 0, Scr.Size)
        Me.BackgroundImage = Screenshot
        Me.Show()
    End Sub

    Private Sub frmCapture_MouseDown(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseDown
        StartPoint = e.Location
    End Sub

    Private Sub frmCapture_MouseMove(sender As System.Object, e As System.Windows.Forms.MouseEventArgs) Handles MyBase.MouseMove
        If e.Button = Windows.Forms.MouseButtons.Left Then
            EndPoint = e.Location
        End If

        If Not StartPoint.IsEmpty And Not EndPoint.IsEmpty Then
            CapRect.Location = New Point(0, 0)
            If EndPoint.X > StartPoint.X Then
                CapRect.Width = EndPoint.X - StartPoint.X
                CapRect.Location = New Point(StartPoint.X, CapRect.Location.Y)
            ElseIf EndPoint.X < StartPoint.X Then
                CapRect.Width = StartPoint.X - EndPoint.X
                CapRect.Location = New Point(EndPoint.X, CapRect.Location.Y)
            End If

            If EndPoint.Y > StartPoint.Y Then
                CapRect.Height = EndPoint.Y - StartPoint.Y
                CapRect.Location = New Point(CapRect.Location.X, StartPoint.Y)
            ElseIf EndPoint.Y < StartPoint.Y Then
                CapRect.Height = StartPoint.Y - EndPoint.Y
                CapRect.Location = New Point(CapRect.Location.X, EndPoint.Y)
            End If
            Invalidate()
        End If
    End Sub

    Private Sub frmCapture_MouseUp(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseUp
        Me.Close()
    End Sub

    Private Sub frmCapture_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        If EndPoint.IsEmpty Or StartPoint.IsEmpty Then Exit Sub
        Dim G As Graphics = e.Graphics
        G.FillRectangle(New SolidBrush(Color.FromArgb(70, Color.Silver)), CapRect)
        G.DrawRectangle(Pens.Silver, CapRect)
    End Sub

End Class