How to Read data from an xdmf file

my code is as follow:

W = VectorFunctionSpace(mesh, 'P', 1)
Q = FunctionSpace(mesh, 'P', 1)
X = Function(W)
with XDMFFile("80.xmf") as outfile:
    # outfile.write(mesh)
    outfile.read_checkpoint(X, "u", 80)

I can’t read the solved data from the xdmf file

Read Read before posting: How do I get my question answered?

In particular, we can’t discuss how to import the solution unless you provide us a code that shows how you actually exported it beforehand.