VB.NET相当于C＃“As”

Question

C＃ As 关键字在VB.NET中的含义是什么，如下所示？

var x = y as String;
if (x == null) ...

Answer 1

是TryCast:

Dim x As String = TryCast(y, String)
If x Is Nothing Then ...

Answer 2

Trycast是您正在寻找的。

Dim x = TryCast(y, String)

Answer 3

TryCast：

Dim x = TryCast(y, String)
if (x Is Nothing) ...

Answer 4

Dim x = TryCast（y，[String]）

Answer 5

你走了：

C＃代码：

var x = y as String;
if (x == null) ...

VB.NET等价物：

Dim x = TryCast(y, String)
If (x Is Nothing) ...

Answer 6

Dim x = TryCast(y, [String])

来自：http://www.developerfusion.com/tools/convert/csharp-to-vb/

Answer 7

您可以将其与?：

一起使用

TryCast(item, String)?.Substring(10)

它允许您在没有if的情况下管理可空：）