Return output from an MsBuild task?

Question

I'd like to calculate a path in a MsBuild task, to be used by another MsBuild task. What is the best way to accomplish this?

Setting a environment variable, printing to Console, ...?

Answer 1

Use a property or an item. Your MSBuild that calculates the path, return it as a property and you use this property as input for your other task.

public class CalculatePathTask : ITask {     [Output]     public String Path { get; set; }      public bool Execute()     {                                            Path = CalculatePath();          return true;     } } 

<Target Name="CalculateAndUsePath">   <CalculatePathTask>     <Output TaskParameter="Path" PropertyName="CalculatePath"/>   </CalculatePathTask>    <Message Text="My path is $(CalculatePath)"/> </Target> 

If you need to pass a value between two MSBuild project, you should create a third one that will call the other using MSBuild Task and use the TargetOutputs element to get back the value that you want.