Tips for Converting Between VB & C#

Even though much of the conversion process between VB and C# seems clearly defined, there are a few insidious and subtle differences between VB and C# — here are just a few examples:

You use the upper bound to initialize arrays in VB; whereas, you use the number of elements in C#. Instant C# and Instant VB correctly adjust all array initializations.
The ending condition of a VB "For" loop is only tested once, on the first entry to the loop; while a C# "for" loop tests the ending condition on every iteration. Instant C# inserts temporary variables set to the ending condition when the ending condition is not constant.
The "Not" operator in VB has significantly different operator precedence than the "!" operator in C#. So, just substituting one for the other will often produce incorrect code.
The following set of translations shows how keyword overlap can be confusing:
- The VB phrase "x Is y" translates to "x == y"
- The VB phrase "TypeOf x Is y" translates to "x is y"
- The VB global method "GetType(x)" translates to "typeof(x)"
  ("x.GetType()" remains "x.GetType()" since this is a .NET intrinsic object method).
Calls to the VB "IIf" function can't be always reliably replaced by the "?" operator and vice versa since the "?" operator uses short-circuit logic (resolving only the required return value) and calls to the "IIf" function do not (since "IIf" is a function, both possible return values are resolved even though only one is ever required). The "If" ternary operator in VB9 and above behaves identically to the C# ternary operator.
VB still allows assigning method return values to the method name (using the method name as a temporary variable). These values are returned by the method upon exiting the method even though a return statement may not have been executed. Further complicating this situation is the fact that VB allows mixing return statements and assignments to the method name. Instant C# correctly converts these to coherent C# code.

Use Instant C# and Instant VB to convert between VB.NET and C#.

Additional resource: VB.NET and C# Comparison and Equivalents