本文所述为VB实现鼠标绘图的实例，该实例实现线条颜色和线宽可自设，当按下鼠标按键时绘图开始并记录最初的起点，如果不是处在绘图状态则退出该过程，如果处在绘图状态则从起点到目前鼠标所在点绘制直线，然后将当前鼠标所在点作为新的起点，当释放鼠标按键时绘图结束。

具体的功能代码如下：

VERSION 5.00Object = "{F9043C88-F6F2-101A-A3C9-08002B2F49FB}#1.2#0"; "comdlg32.ocx"Begin VB.Form Form1 Caption = "鼠标绘图" ClientHeight = 6420 ClientLeft = 60 ClientTop = 345 ClientWidth = 7710 LinkTopic = "Form1" ScaleHeight = 6420 ScaleWidth = 7710 StartUpPosition = 3 '窗口缺省 Begin VB.CommandButton Command2 Caption = "清除" Height = 495 Left = 5640 TabIndex = 7 Top = 1440 Width = 1335 End Begin VB.Frame Frame1 Caption = "线宽" Height = 2655 Left = 5520 TabIndex = 2 Top = 2880 Width = 1935 Begin VB.OptionButton Option4 Caption = "8" Height = 495 Left = 240 TabIndex = 6 Top = 1800 Width = 1215 End Begin VB.OptionButton Option3 Caption = "4" Height = 375 Left = 240 TabIndex = 5 Top = 1320 Width = 1335 End Begin VB.OptionButton Option2 Caption = "2" Height = 375 Left = 240 TabIndex = 4 Top = 840 Width = 1095 End Begin VB.OptionButton Option1 Caption = "1" Height = 255 Left = 240 TabIndex = 3 Top = 480 Value = -1 'True Width = 1335 End End Begin VB.CommandButton Command1 Caption = "设置颜色" Height = 495 Left = 5640 TabIndex = 1 Top = 600 Width = 1215 End Begin MSComDlg.CommonDialog CommonDialog1 Left = 4200 Top = 3840 _ExtentX = 847 _ExtentY = 847 _Version = 393216 End Begin VB.PictureBox Picture1 Height = 5535 Left = 480 ScaleHeight = 5475 ScaleWidth = 4515 TabIndex = 0 Top = 480 Width = 4575 EndEndAttribute VB_Name = "Form1"Attribute VB_GlobalNameSpace = FalseAttribute VB_Creatable = FalseAttribute VB_PredeclaredId = TrueAttribute VB_Exposed = FalseDim x1 As Integer '起点X坐标Dim y1 As Integer '起点Y坐标Dim x2 As Integer '终点点X坐标Dim y2 As Integer '终点Y坐标Dim flag As Boolean '绘图标志'设置线的颜色Private Sub Command1_Click() On Error Resume Next CommonDialog1.CancelError = True CommonDialog1.DialogTitle = "颜色" CommonDialog1.ShowColor If Err <> 32755 Then Picture1.ForeColor = CommonDialog1.Color End IfEnd Sub'清除Picture1中的图形Private Sub Command2_Click() Picture1.ClsEnd Sub'设置线宽Private Sub Option1_Click() Picture1.DrawWidth = 1End SubPrivate Sub Option2_Click() Picture1.DrawWidth = 2End SubPrivate Sub Option3_Click() Picture1.DrawWidth = 4End SubPrivate Sub Option4_Click() Picture1.DrawWidth = 8End SubPrivate Sub Form_Load() Picture1.Scale (0, 0)-(400, 400) flag = FalseEnd SubPrivate Sub Picture1_MouseDown(Button As Integer, Shift As Integer, _X As Single, Y As Single)'当按下鼠标按键时绘图开始并记录最初的起点 flag = True x1 = X y1 = YEnd SubPrivate Sub Picture1_MouseMove(Button As Integer, Shift As Integer, _X As Single, Y As Single)'如果不是处在绘图状态则退出该过程'如果处在绘图状态则从起点到目前鼠标所在点绘制直线'然后将当前鼠标所在点作为新的起点 If flag = False Then Exit Sub End If If flag = True Then x2 = X y2 = Y Picture1.Line (x1, y1)-(x2, y2) x1 = x2 y1 = y2 End IfEnd SubPrivate Sub Picture1_MouseUp(Button As Integer, Shift As Integer, _X As Single, Y As Single)'当释放鼠标按键时绘图结束 flag = FalseEnd Sub

程序中备有较为详细的注释，相信读者不难理解，读者可以根据自己的喜好对该程序进行修改，使之更加完善！