VB代码缩进优化: 公制螺纹孔直径与管螺纹孔规格对应关系

"If 公制螺纹孔直径 = 0 Then\n If 管螺纹孔规格 = "1/8" Then\n 螺纹大径 = 9.728\n ElseIf 管螺纹孔规格 = "1/4" Then\n 螺纹大径 = 13.157\n ElseIf 管螺纹孔规格 = "3/8" Then\n 螺纹大径 = 16.662\n ElseIf 管螺纹孔规格 = "1/2" Then\n 螺纹大径 = 20.955\n ElseIf 管螺纹孔规格 = "5/8" Then\n 螺纹大径 = 22.911\n ElseIf 管螺纹孔规格 = "3/4" Then\n 螺纹大径 = 26.441\n ElseIf 管螺纹孔规格 = "7/8" Then\n 螺纹大径 = 30.201\n ElseIf 管螺纹孔规格 = "1" Then\n 螺纹大径 = 33.249\n ElseIf 管螺纹孔规格 = "1-1/8" Then\n 螺纹大径 = 37.897\n ElseIf 管螺纹孔规格 = "1-1/4" Then\n 螺纹大径 = 41.91\n ElseIf 管螺纹孔规格 = "1-1/2" Then\n 螺纹大径 = 47.803\n ElseIf 管螺纹孔规格 = "1-3/4" Then\n 螺纹大径 = 53.746\n ElseIf 管螺纹孔规格 = "2" Then\n 螺纹大径 = 59.614\n Else\n 螺纹大径 = 0\n End If\nElse\n 螺纹大径 = 公制螺纹孔直径\nEnd If\n