blockOperationWithBlock:
Creates and returns an
NSBlockOperation object and adds the specified block to it.
+ (id)blockOperationWithBlock:(void (^)(void))block
Parameters
- block
- The block to add to the new block operation object’s list. The block should take no parameters and have no return value.
Return Value of [NSBlockOperation blockOperationWithBlock]
A new block operation object.
Example of [NSBlockOperation blockOperationWithBlock]
- (NSOperation *)executeBlock:(void (^)(void))block inQueue:(NSOperationQueue *)queue completion:(void (^)(BOOL finished))completion {
NSOperation *blockOperation = [NSBlockOperation blockOperationWithBlock :block];
NSOperation *completionOperation = [NSBlockOperation blockOperationWithBlock:^{
completion(blockOperation.isFinished);
}];
[completionOperation addDependency:blockOperation];
[[NSOperationQueue currentQueue] addOperation:completionOperation];
[queue addOperation:blockOperation];
return blockOperation;
}
- (void)testIt {
backgroundOperationQueue = [[NSOperationQueue alloc] init];
NSMutableString *string = [NSMutableString stringWithString:@"tea"];
NSString *otherString = @"for";
NSOperation *operation = [self executeBlock:^{
NSString *yetAnother = @"two";
[string appendFormat:@" %@ %@", otherString, yetAnother];
} completion:^(BOOL finished) {
// this logs "tea for two"
NSLog(@"%@", string);
}];
NSLog(@"keep this operation so we can cancel it: %@", operation);
}
Example of [NSBlockOperation blockOperationWithBlock]
_requestA = [NSBlockOperation blockOperationWithBlock:^{
// Normal requestA code here.
// ...
// Assuming you create all requestA and requestB instances on the main thread...
dispatch_async(dispatch_get_main_queue(), ^{ _requestA = nil; });
}];