I want to display a Listbox selected item in a text area to plot it in a mesh graph

I am adding items into a listbox using the below code:

% Button pushed function: ExecuteButton

function ExecuteButtonPushed2(app, event)

dx=app.RoadStepSize_dx_EditField.Value;

xMax=app.MaxRoadLength_xMax_editfield.Value;

vMax=app.MaxVelocity_vMax_EditField.Value;

tMax=app.SimulationTime_tMaxEditField.Value;

dt=app.TimeStep_dt_EditField.Value;

dir

c0=app.C0TimeheadwayEditField.Value;

tau=app.RelaxationTime_TauEditField.Value;

pMax=app.MaxDensity_pMaxEditField.Value;

Mat_Type=app.Hidden_Numeric_EditField.Value

[m,dis,myfile] =srch(pMax,dx,xMax,vMax,tMax,dt,c0,tau,Mat_Type);

app.DataFileTextArea.Value=dis;

if app.DataFileTextArea.Value~="File Not Found"

app.ListBox.Items{length(app.ListBox.Items)+1}=app.DataFileTextArea.Value{1};

end

I've added graphs where I want to plot the loaded file, and I'd like to display the loaded file in a text area that will be used to find the.mat file in my database and load it, and plot specific matrecis in a graph where I want it to be plotted, with different buttons for each variable to be plotted for each plot area..

I am trying to do this as below

app.Selected_file.Value = app.ListBox.Value;

But i am unable to even display the selected item from the list box, so my question is either how to display a selected item of a list box in a text area.