start a while loop on working with a file in gui

Help me please! I need to make a loop that will read information from the file

function pushbutton1_Callback(hObject, eventdata, handles)
[file,path] = uigetfile('*.apa'); 
[file, ~] = fopen(fullfile(path,file));
fileinfo=dir(path); 
filesize=fileinfo.bytes;
i=1
while (~feof(file)) && (ftell(file)<filesize)
a=fread(file,[1,1],'single');
b=fread(file,[1,1],'single');
addz=fread(file,[1,1],'single');
bitadd=fread(file,[1,1],'single');
if (addz==1)&&(bitand(bitadd,16))
    ad(i)=a
    bd(i)=b
    for j=1:length(ad)
        intaddora(j)=a(j)+1;
        intaddorb(j)=a(j)-1;;
    end
    i=i+1
end
end

The first part opens the file and I want it to be immediately considered in the loop? , but in static text i = 1, i.e. the cycle does not count, please help me fix it

[Ajay Kumar]

put a breakpoint on last but 3rd line and see why i is not incrementing.

Does it going into if loop first of all?

[Rik]

Both conditions in your while seem to check the same thing. Why are you using them both?

[Lev Mihailov]

while (~feof(file)) && (ftell(file)<filesize) % reading to the end of the file or the end will fit its end
a=fread(file,[1,1],'single'); %  % number of a and b equal to 1x100
b=fread(file,[1,1],'single'); % [ 10 20 30 40 10 11 20 ...]
addz=fread(file,[1,1],'single'); % addz=1x100 [ 1 2 3 4 1 1 2 4 1 5 ...]
bitadd=fread(file,[1,1],'single');
if (addz==1)&&(bitand(bitadd,16))
    ad(i)=a 
    bd(i)=b % [10 10 11 ...]
    for j=1:length(ad)
        intaddora(j)=a(j)+1;
        intaddorb(j)=a(j)-1;; % [9 9 10 ...]
    end
    i=i+1
end
end

and please specify where to put the point and how to do it?

[Lev Mihailov]

in some files you need to tighten checks (files were not written correctly)

[Rik]

You can enable breakpoints by clicking on the dash next to the line number in the editor.