OSX application freezes when try to set the value of TextView? - objective-c

Question

I am really new to Objective-C.
First please see the code:
Here it is the property:
#property (atomic) IBOutlet NSTextView *txtResponse;
And here it is the action:
- (IBAction)sendReq:(id)sender {
#synchronized(self)
{
request *req = [[request alloc] init];
voidCallback callback = ^(NSURLResponse *resp, NSData *data, NSError *error) {
NSString *val = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
[self.txtResponse setString:val];
//NSLog(val);
};
[req setUrl:[[NSURL alloc] initWithString:#"http://foo.bar"]];
[req setCallback:callback];
[req send];
}
}
The UI freezes when I try to use [self.txtResponse setString:val];
I also tried the code without #synchronized(self)
Where is the problem?
Thanks in advance!

Answer 1

3rd day that I am working with objective-c and finally found the answer :)
I used the performSelectorOnMainThread and solved the problem
- (IBAction)sendReq:(id)sender {
request *req = [[request alloc] init];
voidCallback callback = ^(NSURLResponse *resp, NSData *data, NSError *error) {
NSString *val = [[NSString alloc] initWithData:data encoding:NSUTF8StringEncoding];
[self performSelectorOnMainThread:#selector(setResponseValue:) withObject:val waitUntilDone:NO];
};
[req setUrl:[[NSURL alloc] initWithString:#"http://programming.com"]];
[req setCallback:callback];
[req send];
}
- (void)setResponseValue:(NSString *)resp
{
[self.txtResponse setString:resp];
//NSLog(resp);
}