CODEWITHSUNDEEP
c#.netvisual-studiot4
user310291
user310291

Reputation: 38190

c# error: Use of unassigned local variable (context visual studio T4 ENGINE)

In C# (within the context of T4 template see http://www.olegsych.com/2008/03/how-to-generate-multiple-outputs-from-single-t4-template/) I want to do this

<# String myTemplateVar; 
#>

<# if (string.IsNullOrEmpty(myTemplateVar)) { 
    myTemplateVar= "name";
}; 
#>

I want to give a value to myTemplateVar if myTemplateVar has not already been setup by an external call from T4 engine in another template which would have this instruction:

CallContext.SetData("myTemplate.myTemplateVar", ExternalTemplateVar);

But I cannot even compile in C# why ? How to fix this ?

This kind of stuff is easy to do in PHP I don't understand why in C# it seems so complicated.

Update: the problem is that if I initialize to either Null or Empty to avoid compilation error, how can I detect that the variable has been setup by an external call ?

Upvotes: 2

Views: 1781

Answers (3)

GarethJ
GarethJ

Reputation: 6606

The myTemplateVar variable as defined above is at method scope inside the class underlying the template (inside the TransformText method).If you'd like a class-level, then you could use a class feature block, like so.

<#+ public string myTemplateVar; #>

or even a class static:

<#+ public static string myTemplateVar; #>

However, there's still no way to tell whether the variable has been set, other than by its null value or not though for a reference type in C#.

Upvotes: 3

Neil Knight
Neil Knight

Reputation: 48547

Try:

<# String myTemplateVar = String.Empty;  #>

in order to resolve the compile error.

Upvotes: 2

MPelletier
MPelletier

Reputation: 16687

Have you tried giving your string a default value? If it does not get in the if block, it will remain unassigned.

Upvotes: 1

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