什么是VB.net中的:= [英] What is := in VB.net

问题描述

好吧，主题告诉了一切...
我找不到VB.NET中的:=功能...

这里是一个示例...

SwitchDesktop(hDesktop:= p_lngHwnd)


有人可以告诉我吗?

谢谢:)

Well, subject tells everything ...
I can''t find what := does in VB.NET ...

Here''s one example ...

SwitchDesktop(hDesktop:=p_lngHwnd)


Can anyone tell me ?

thanks :)

推荐答案

它"表示命名参数.例如:

It''s for named parameters. For example:

<br />Sub ShowMsg(ByVal a as String, ByVal b as String, ByVal c as String)<br />  MsgBox(a & b & c)<br />End Sub<br /><br />Sub Main()<br />  ''Notice how a, b, and c are out of order.<br />  ShowMsg(c := "!", b := " World", a := "Hello")<br />End Sub<br />

除非我弄错了，否则:=允许您按名称和位置传递变量(下面的示例是徒手的).

示例子:子测试(byval Value1作为字符串，byval Value2作为整数，byval Value3作为对象)

按位置调用的常规方法:调用sub test("value1"，2，新对象)
按名称调用:调用子测试(Value3:=新对象，Value2:= 2，Value3:="doh！")


通常，您会看到:=在属性中使用.

Unless I am mistaken, := allows you to pass variables by name vs. by position (example below is freehand).

Example sub: sub test (byval Value1 as string, byval Value2 as integer, byval Value3 as object)

Normal way to call by position: Call sub test("value1", 2, new object)

call by name: Call sub test(Value3:= New object, Value2:=2, Value3:="doh!")


Generally you see the := used in attributes.

这篇关于什么是VB.net中的:=的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！