VB到C#函数

Question

哪些是从VB.Net到C#的以下运算符的等价物？

• UBound函数()
• LBOUND()
• 没什么()
• CHR()
• LEN()
• 用Ucase()
• LCASE()
• 剩下()
• 对()
• RTRIM()
• LTRIM()
• 修剪()
• 中()
• 更换()
• 分裂()
• 加入()
• MSGBOX()
• IIF()

Answer 1

VB             C#

UBound()     = yourArray.GetUpperBound(0) or yourArray.Length for one-dimesional arrays
LBound()     = yourArray.GetLowerBound(0)
IsNothing()  = Object.ReferenceEquals(obj,null)
Chr()        = Convert.ToChar()
Len()        = "string".Length
UCase()      = "string".ToUpper()
LCase()      = "string".ToLower()
Left()       = "string".Substring(0, length)
Right()      = "string".Substring("string".Length - desiredLength)
RTrim()      = "string".TrimEnd()
LTrim()      = "string".TrimStart()
Trim()       = "string".Trim()
Mid()        = "string".Substring(start, length)
Replace()    = "string".Replace()
Split()      = "string".Split()
Join()       = String.Join()
MsgBox()     = MessageBox.Show()
IIF()        = (boolean_condition ? "true" : "false")

笔记

• yourArray.GetUpperBound(0)vs yourArray.Length:如果数组是零长度,GetUpperBound将返回-1,而Length将返回0. UBound()在VB.NET中将返回-1为零长度数组.
• VB字符串函数使用一个基于索引,而.NET方法使用基于零的索引.即Mid("asdf",2,2)对应"asdf".SubString(1,2).
• ?并不是完全相同的IIf因为,IIf总是计算两个参数,并且?只评估它需要的参数.这可能很重要,如果有评价的副作用〜不寒而栗!
• 在许多经典VB字符串的功能,包括Len(),UCase(),LCase(),Right(),RTrim(),和Trim(),将治疗的参数Nothing(Null在C#)为等同于一个零长度的字符串.Nothing当然,运行字符串方法会抛出异常.
• 您还可以传递Nothing给经典的VB Mid()和Replace()函数.这些将返回,而不是抛出异常Nothing.

Answer 2

UBound()  "array".Length
LBound()
IsNothing(): "object" == null
Chr()     (char)"N"
Len()     "string".Length
UCase()   "string".ToUpper()
LCase()   "string".ToLower()
Left()    "string".Substring(from, to)
Right()   "string".Substring(from, to)
RTrim()   "string".TrimEnd()
LTrim()   "string".TrimStart()
Trim()    "string".Trim()
Mid()     "string".Substring(from, to)
Replace() "string".Replace()
Split()   "string".Split()
Join()    String.Join()
MsgBox()  MessageBox.Show()
IIF()     validate ? iftrue : iffalse;