Iosnsoperation Dependency Relationship

Nsoperation dependencies, just like you and your girlfriend, need each other the same. Very interesting.

#import "ViewController.h"

@interface viewcontroller ()

@end

@implementation Viewcontroller

-(void) viewdidload {

[superviewdidload];

// operation Dependent

// The time-consuming operation of processing pictures is performed in a child thread

nsblockoperation *blockop = [nsblockoperation Blockoperationwithblock: ^{

NSLog(@ "Blockop download picture thread =%@", [NsthreadCurrentThread]);

}];

nsblockoperation *blockop1 = [nsblockoperation Blockoperationwithblock: ^{

NSLog(@ "BlockOp1 adds a watermark to a picture thread =%@", [Nsthread CurrentThread]);

}];

nsblockoperation *blockop2 = [nsblockoperation Blockoperationwithblock: ^{

[nsthreadsleepfortimeinterval:2.0];

NSLog(@ "BlockOp2 save picture thread =%@", [ Nsthreadcurrentthread]);

}];

// Add dependencies to BlockOp1 to make blockOp1 in Blcokop Execute after execution finishes

[blockOp1 adddependency: Blockop]; // that is, after the download is finished, add a watermark to the image and save the picture. A dependent relationship

[blockOp2 adddependency: blockOp1];

// Create a queue (throw in the queue what you want to do--something like Asynchronous in GCD, concurrency, multiple threads turned on)

nsoperationqueue *queue = [[nsoperationqueuealloc] Init ];

// add to queue

[Queue addoperation: Blockop];

[Queue addoperation: blockOp1];

[Queue addoperation: blockOp2];

// Set the maximum number of simultaneous operations in the queue, that is, the current queue is executed at the same time by several threads, typically allowing the maximum number of concurrent 2 or 3

[Queue setmaxconcurrentoperationcount:3];

    //

for (int i =0; i< ; i++) {

nsblockoperation *blockopp = [nsblockoperationblockoperationwith Block: ^{

NSLog(@ "Blockopp i =%d thread =%@", i,[nsthread currentthread ]);

}];

[Queue addoperation: Blockopp];

}

// refresh UI operation dependencies must be performed in the main thread

nsblockoperation *blocopmain = [nsblockoperation Blockoperationwithblock: ^{

NSLog(@ "Blockopmain refresh UI display picture , thread =%@" , [nsthreadcurrentthread]);

}];

// The dependencies of the two operations, cross-queue

[Blocopmain adddependency: blockOp2];

// home Row

[[nsoperationqueuemainqueue]addoperation: Blocopmain] ;

}

@end

Iosnsoperation Dependency Relationship