繪圖部分一直是我不熟悉的領域，最近想弄一些東西應該會來研究一下，下面這段程式在Form上面按住左鍵後移動滑鼠便會畫出矩形，算是第一步吧 ~
- Dim BG As Bitmap
- Dim G As Graphics
-
- Dim IsMouseDown As Boolean = False
- Dim P_Start As New Point
-
- Private Sub frmEdit_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
- Me.Show()
- Application.DoEvents()
- BG = New Bitmap(PictureBox1.Width, PictureBox1.Height)
- G = Graphics.FromImage(BG)
- End Sub
-
- Private Sub PictureBox1_MouseDown(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseDown
- IsMouseDown = True
- P_Start = e.Location
- End Sub
-
- Private Sub PictureBox1_MouseMove(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseMove
- If IsMouseDown Then
- G.Clear(Color.Transparent)
- If e.X - P_Start.X > 0 Then
- If e.Y - P_Start.Y > 0 Then
- G.DrawRectangle(New Pen(Color.Pink, 2), _
- New Rectangle( _
- P_Start.X, P_Start.Y, e.X - P_Start.X, e.Y - P_Start.Y))
- Else
- G.DrawRectangle(New Pen(Color.Pink, 2), _
- New Rectangle( _
- P_Start.X, e.Y, e.X - P_Start.X, P_Start.Y - e.Y))
- End If
- Else
- If P_Start.Y - e.Y > 0 Then
- G.DrawRectangle(New Pen(Color.Pink, 2), _
- New Rectangle( _
- e.X, e.Y, P_Start.X - e.X, P_Start.Y - e.Y))
- Else
- G.DrawRectangle(New Pen(Color.Pink, 2), _
- New Rectangle( _
- e.X, P_Start.Y, P_Start.X - e.X, e.Y - P_Start.Y))
- End If
- End If
- PictureBox1.Image = BG
- End If
- End Sub
-
- Private Sub PictureBox1_MouseUp(ByVal sender As Object, ByVal e As System.Windows.Forms.MouseEventArgs) Handles PictureBox1.MouseUp
- G.Clear(Color.Transparent)
- IsMouseDown = False
- End Sub