Cat learns the magic of the block of iOS using block for chained programming

Cat Share, must boutique

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Address: http://blog.csdn.net/u013357243

One: Scene

We have an object, he has two methods, one is learning study, the other is running run,
This person has a quirk, must learn after running, in order to achieve this method and can be invoked conveniently, we let running and learning to return to their own this object as a shortcut to the next call, the code is as follows:
Call:

int main(intconstchar * argv[]){    @autoreleasepool {    //初始化人        Person *p = [[Person alloc] init];        //调用        [[p study] run];    return0;}

Person object:

//Person.h   #import <FOUNDATION/FOUNDATION.H>    @interface  person : nsobject  -(person *) study;-(person *) run;  @end   

// Person.m#import "Person.h"@implementation Person- (Person *)study{    NSLog(@"study----");    returnself;}- (Person *)run{    NSLog(@"run----");    returnself;}@end

Run results

Two: Block chain-type structure implementation

Call:

int main(intconstchar * argv[]){    @autoreleasepool {        Person *p = [[Person alloc] init];        p.study(@"xx宝典").run().study(@"xx剪发");    }    return0;}

Person object:

//Person.h@interface Person : NSObject- (Person *(^)(NSString *name))study;- (Person *(^)())run;@end

//Person.m@implementation Person- (Person *(^)(NSString *))study{    return ^(NSString *name){        NSLog(@"study----%@", name);        returnself;    };}- (Person *(^)())run{    return ^{        NSLog(@"run----");        returnself;    };}@end

In this area, we

P.study (@ "xx treasure book"). Run (). Study (@ "XX hair cut");
Call study method: P.study
Execute Block:p.study (@ "xx Treasure book")
Combining the method of person's internal writing

- (Person *(^)(NSString *))study{    return ^(NSString *name){        NSLog(@"study----%@", name);        returnself;    };}

Obviously, when executing p.study (@ "xx treasure"), the inside is a return value is the block of the person* type (the last return self), which explains why the next sentence can continue to be invoked with a point. This means that a block is returned, and there is a return value in the block, and the return value is the object self of the person.
The parameters here are a bit dizzy, remember, with the clever use of a chain-structured block, simply understand it.

Execution results

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Cat learns the magic of the block of iOS using block for chained programming