很奇怪，变量丢失的问题

[bigenterprise]

fid = fopen('shuju1.txt','r');
if fid==-1
msgbox ('Please open a file');
else
handles.fid=fid;
datainformation=fgets(fid,100);
name=fgets(fid,1000);
time=fgets(fid,100);
time1=time(13:22);
%set(handles.text_time,'String',time1);
fscanf(fid,'%c',19);
channelnumtemp=fscanf(fid,'%d',1);
handles.channelnum=channelnumtemp;
strChannelnum=num2str(handles.channelnum,2);

这个程序执行到strChannelnum=num2str(handles.channelnum,2);的时候，变量handles.channelnum就会丢失，将num2str(handles.channelnum,2);中的handles.channelnum换成channelnumtemp，这个变量也会丢失，很奇怪，不知道什么原因，请大家想想办法