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错误
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编译错误:“Cancel”不是“e”的成员。

错误代码：e.Cancel = True
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确定  
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AfterOpenProject代码如下：

Dim sucess As Boolean = False
mu = new System.Threading.Mutex(True, "12+3措施暨法律文书规范化",sucess)
If not sucess Then
    MessageBox.Show("同一个软件只能打开一次!","温馨提示")
    e.Cancel = True
Else
    vars("当前年度")=Date.today.Year
    vars("当前月份")=Date.today.Month
    Dim web As new WebPlatform.ProStart()
    web.Show()
End If