Saving graph from GUI as .fig works, but not as .png

In my GUI i have an axes with some random plot in it. I am trying to save this graph as a figure and as a .png by pressing a button. I already know that in order to save the axes only (not the whole GUI window), i have to create a new figure, and then use COPYOBJ to copy that axes to the new figure. This is where I got the idea and code from. It looks like this:

        fignew = figure('Visible','off'); % Invisible figure
        newAxes = copyobj(handles.axes1,fignew); % Copy the appropriate axes
        set(newAxes,'Position',get(groot,'DefaultAxesPosition')); % The original position is copied too, so adjust it.
        set(fignew,'CreateFcn','set(gcbf,''Visible'',''on'')'); % Make it visible upon loading
        set(fignew, 'PaperPositionMode', 'auto');

         print(fignew,filename,'-dpng')   
         %export_fig(fignew, filename); %using export_fig as a second option as it is recommended often 
         savefig(fignew,[filename,'.fig']);

While the saved figure looks perfectly fine,

the .png files look like this:

by using export_fig and the following one by using print:

As you can see in the first image, the graph is squeezed to a very small size and sits in the bottom left corner. The rest is white space only. The second image consits of the small size graph only. I don't know what is happening there.

I appreciate every bit of help and want to thank you for taking your time reading this.

Answer 1

[gummivogel]

My mistake. I didnt know that the units of my axes are set to pixels when creating it. Adding the line

     set(handles.axes1,'units','normalized')

solved my problems.

Answer 2

[Jan]

Please try to insert a drawnow command. It seems, like the new figure is not updated correctly, when it is created with Visible='off'.

What happens if you run this with a visible figure?