Question

我正在尝试创建一个用户可修改的字符串，该字符串已经设置了数据以替换某些文本补丁

例如

dim name1 as string = "John"
dim state as string = "Virginia"
dim idnumb as integer = 122
dim textlist1 as string

textlist1 = "Hello {NAME}, I see you are from {STATE}, and your id number is {ID}."

理想情况下，我想用set string

替换这些标签

我熟悉

Replace(textlist1, "{NAME}", name1)

我的问题是：这是正确的方法吗？还是有一种方法更像我们在MySql中做参数的方式

Answer 1

理想情况下，您可以使用StringBuilder来避免为每个替换重新分配新字符串。

dim name1 as string = "John"
dim state as string = "Virginia"
dim idnumb as integer = 122
dim textlist1 as StringBuilder = new StringBuilder _ 
             ("Hello {NAME}, I see you are from {STATE}, and your id number is {ID}.")
textlist1.Replace("{NAME}", name1)

假设StringBuilder方法不是性能相关比较的最佳方法这只是通过LinqPad执行的一个小基准

Sub Main
    dim name1 as string = "John"
    dim state as string = "Virginia"
    dim idnumb as integer = 122
    dim textlist1 as StringBuilder 

    Dim sw = new Stopwatch()
    sw.Start()
    for i = 0 to 100000
        textlist1 = new StringBuilder("Hello {NAME}, I see you are from {STATE}, and your id number is {ID}.")
        textlist1.Replace("{NAME}", name1)
        textlist1.Replace("{STATE}", state)
        textlist1.Replace("{ID}", idnumb.ToString())
    Next
    sw.Stop()
    sw.Elapsed.Dump("StringBuilder.Replace")

    sw = new Stopwatch()
    sw.Start()
    for i = 0 to 100000
        Dim test = "Hello {NAME}, I see you are from {STATE}, and your id number is {ID}."
        Dim test2 = test.Replace("{NAME}", name1)
        Dim test3 = test2.Replace("{STATE}", state)
        Dim test4 = test3.Replace("{ID}", idnumb.ToString())
    Next
    sw.Stop()
    sw.Elapsed.Dump("String.Replace")
End Sub

StringBuilder.Replace 
00:00:00.2795878 

String.Replace 
00:00:00.1642420

因此，分配字符串生成器的成本似乎超过了使用固定的实习字符串的成本。当然，由不可变字符串行为引起的内存碎片不容易测量。

在类似于mysql的字符串中替换参数

1 个答案: