Use Block to Call Back Instead of Delegate

Some days ago, i posted the blog to introduce some ways to talk to each oher between Object A and B. One of the points is Blocks. Now I will show how to call back use Block instead of Delegate.

Some codes posted as follow:

A：SWDPromptViewController

.h
//declare a block named "dismissPromptViewBlock".
@property (copy, nonatomic) void(^dismissPromptViewBlock)    (SWDPromptViewController *prompt);

.m
//after some operations, we will dismiss A and release it.
-(void)dismissPrompt
{
    if (self.dismissPromptViewBlock)
    {
        self.dismissPromptViewBlock(self);
        self.dismissPromptViewBlock = nil;
    }
}


B：
.m
//declare A object and init it,then assign a block to the property of A.
//so when A executes the method "dismissPrompt", the block plays a part of
//Delegate.
SWDPromptViewController *promptViewController = [[SWDPromptViewController     alloc] initWithNibName:@"SWDPromptViewController" bundle:nil type:type];
UIWindow *promptWindow = [[UIWindow alloc] initWithFrame:[[UIScreen     mainScreen] bounds]];
promptWindow.windowLevel = UIWindowLevelAlert;
promptWindow.backgroundColor = [UIColor clearColor];
promptWindow.rootViewController = promptViewController;
[promptViewController release];
[promptWindow makeKeyAndVisible];

promptViewController.dismissPromptViewBlock = ^(SWDPromptViewController     *prompt){

    [promptWindow release];
    };

That is all. Welcome to communicate with me.O(∩_∩)O~.