How can I use Camera GigE vision?

I'm using Appdesigner to control My Camera (it is a GigE Vision Camera).

My objectif is to aquire images from the camera.

i download the package needed for that.

i created the a GigE object. every things went well.

I need to use (preview) before using snapshot.

The code works very slowly (in preview Mode: the image changes every 10 or 20 seconds instead of becoming near realtime), In addition to that: while the camera is connected to the laptop (which it should be), the entire code (even for the operations and components not related to the camera) become very very slow, i can't even move the mouse on my screen or open other window. once i deconnect the camera GigE, every things become normale, all operations could be acheived easily and fast.

i feel that i'm not using the camera with the optimized way.

In startupFcn: i initialize my object as below:

app.cam=gigecam; % initialse an object for the camera.

app.WidthEditField.Value=double(app.cam.Width);

app.HeightEditField.Value=double(app.cam.Height);

app.ExposureTimeEditField.Value=double(app.cam.ExposureTime);

app.GainEditField.Value=double(app.cam.Gain);

app.row=app.cam.Height;

app.colume=app.cam.Width;

app.ExposureTime=app.cam.ExposureTime;

app.Gain=app.cam.Gain;

In Preview Button Pushed: i wrote the part below:

frame=snapshot(app.cam);

im=image(app.UIAxes,zeros(size(frame),'uint8'));

axis(app.UIAxes,'image');

app.UIAxes.Children=preview(app.cam,im);

In snapshot Button Pushed:I wrote the part below :

im1=snapshot(app.cam);

axis(app.UIAxes,'image');

imshow(im1,'parent',app.UIAxes);

best regards