弄个有偿答题估计也不错

好的

Public Class frmLine
Private Sub Label5_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Label5.Click
'从界面的文本框读取坐标点
Dim OriginalPoint As New Point
Dim LastPoint As New Point
OriginalPoint.X = Me.txbXCoor1.Text
OriginalPoint.Y = Me.txbYcoor1.Text
LastPoint.X = Me.txbXcoor2.Text
LastPoint.Y = Me.txbYcoor2.Text
'进行坐标变换
Dim NewPoint1 As New Point
Dim NewPoint2 As New Point
NewPoint1 = frmMain.CoordinateTransformFromEngineeringToGDI(OriginalPoint)
NewPoint2 = frmMain.CoordinateTransformFromEngineeringToGDI(LastPoint)
'创建画笔
Dim myColor As Color = Color.White
Dim mypen As New System.Drawing.Pen(System.Drawing.Color.White)
frmMain.g.DrawLine(mypen, NewPoint1, NewPoint2)
'更新PictureBox控件的Image
frmMain.PictureBox1.Image = frmMain.MyBitMap
End Sub
End Class

感觉有点怪怪的你似乎没在画板上画呀，什么版本俺明天上机看下。感觉好怪