[英]How to use Progress parameter in AFNetworking 2.0
I am trying to use AFNetworking 2.0 with NSURLSession. 我正在尝试将AFNetworking 2.0与NSURLSession一起使用。 I am using the method
我正在使用这种方法
- (NSURLSessionUploadTask *)uploadTaskWithRequest:(NSURLRequest *)request
fromFile:(NSURL *)fileURL
progress:(NSProgress * __autoreleasing *)progress
completionHandler:(void (^)(NSURLResponse *response, id responseObject, NSError *error))completionHandler;
How am I supposed to use the progress parameter. 我该如何使用progress参数。 The method is a non blocking method.
该方法是一种非阻塞方法。 Hence I will have to listen to the '
progress
' to get the updates. 因此,我将不得不听取“
progress
”以获得更新。 But the parameter wouldn't take a property. 但参数不会占用属性。 Only takes a local variable(NSProgress * __autoreleasing *).
只接受局部变量(NSProgress * __autoreleasing *)。 I can't add KVO to a local var.
我无法将KVO添加到本地var。
I am not really sure how to use. 我不太确定如何使用。
Any time an argument is given as **
it means that you're supposed to pass in the pointer to the pointer to an existing object, not a pointer to the actual object as you would normally do. 任何时候一个参数都是
**
这意味着你应该将指针传递给指向现有对象的指针,而不是像往常那样传递给实际对象的指针。
In this case, you pass in a pointer to a pointer to an NSProgress
object and then observe the changes in that object in order to get the updates. 在这种情况下,您传入指向
NSProgress
对象的指针,然后观察该对象中的更改以获取更新。
Example: 例:
// Create a progress object and pass it in
NSProgress *progress;
[sessionManager uploadTaskWithRequest:request fromFile:fileURL progress:&progress completionHandler:^(NSURLResponse *response, id responseObject, NSError *error) {
// Completion code
}];
// Observe fractionCompleted using KVO
[progress addObserver:self
forKeyPath:@"fractionCompleted"
options:NSKeyValueObservingOptionNew
context:NULL];
Then it gets reported in: 然后报告:
- (void)observeValueForKeyPath:(NSString *)keyPath ofObject:(id)object change:(NSDictionary *)change context:(void *)context
{
[super observeValueForKeyPath:keyPath ofObject:object change:change context:context];
if ([keyPath isEqualToString:@"fractionCompleted"] && [object isKindOfClass:[NSProgress class]]) {
NSProgress *progress = (NSProgress *)object;
NSLog(@"Progress is %f", progress.fractionCompleted);
}
}
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