Excel中输入1时单元格显示为勾

如图：

Private Sub Worksheet_Change(ByVal Target As Range)
    On Error Resume Next
    Application.EnableEvents = False
    For Each c In Target.Cells
        With c
        For i = 1 To 30
         If Cells(i, 1) = 1 Then '判断是否在第1列(a列)输入数据.
           Value = "√"
            End If
                 
            Next
         End With
    Next
    Application.EnableEvents = True
End Sub