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Visual Basic Attribute Examples
Consider the case where you have a Gurobi model 
. You can
retrieve the number of variables in the model by querying the
NumVars model attribute
(which is implemented as a .NET property):
cols = m.NumVars;
If you've performed optimization on the model, the optimal objective value can be obtained by querying the ObjVal model attribute:
obj = m.ObjVal;
If you'd like to query the value that a variable takes in the computed solution, you can query the X attribute for the corresponding variable object:
vars = m.GetVars()
For j As Integer = 0 To cols - 1
xj = vars[j].X
You can also query the value of 
for multiple variables in a single
call using the
Get method
on the model :
xvals = m.Get(GRB.DoubleAttr.X, m.GetVars()))
For each attribute query method, there's an analogous 
routine.
To set the upper bound of a variable, for example:
v = m.GetVars()[0] v.UB = 0(In this example, we've set the upper bound for the first variable in the model to 0).
