The block in Swift's closure oc resolves the circular reference

Global macro definition in OC

#define WS (weakself) __weak __typeof (&*self) weakself = self;

Use the following:

WS (weakself)

[Self.tableview addheaderwithcallback:^{

[Weakself requestmemberlist];

}];

Swift uses weakself in a closed packet

weak var weakself = self
Demo4 {
The advantage of using is that once self is released, nothing is done.
Weakself?. View.backgroundcolor =uicolor.redcolor ()
}

This is the Advanced method:

A class in Swift can be nested to define another class, and the newly added class will only be used by the current class

In Swift, to dismiss a circular reference to a closure, you can use [unowned self] or [weak self] in the closure definition, where:

[unowned Self] is similar to unsafe_unretained in OC, if the object is freed, still retains an invalid reference, not an option

[Weak self] similar to the __weak in OC, if the object is released, automatically points to nil, more secure

[weakself] always monitor poor performance, [unowned self] may cause wild pointer errors, if you can determine that the object will not be released, try to use unowned

Example lazy-loaded closures

Lazy var printname: ()--() = {[unowned self] in

Print (Self.name)

}

The following sentence does not occur because a circular reference will disappear after execution

Lazy var title:string = {

Print (Self.name)

Return "Mr. \ (self.name)"

}()

The block in Swift's closure oc resolves the circular reference