Ios-queue Group

Last Update:2015-10-01 Source: Internet

Author: User

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<pre>////HMVIEWCONTROLLER.M//03-queue Group (learn)////Created by Apple on 14-9-16.//Copyright (c) 2014 Heima. All Rights Reserved.//#import "HMViewController.h"//1. Download 2 pictures respectively: Big picture, LOGO//2. Merge 2 photos//3. Display to a imageview body@interfacehmviewcontroller () @property (weak, nonatomic) iboutlet uiimageview*imageView, @property (nonatomic, Strong) UIImage*image1, @property (nonatomic, Strong) UIImage*image2;@end@implementationHmviewcontroller- (void) Viewdidload{[super viewdidload]; }//2D Drawing quartz2d//merged Image--watermark- (void) touchesbegan: (nsset *) touches withevent: (uievent *)Event{ //1. Queue Groupsdispatch_group_t Group =dispatch_group_create (); dispatch_queue_t Queue= Dispatch_get_global_queue (dispatch_queue_priority_default,0); //2. Download picture 1__block UIImage *image1 =nil; Dispatch_group_async (group, queue,^{nsurl*URL1 = [nsurl urlwithstring:@"http://g.hiphotos.baidu.com/image/pic/item/f2deb48f8c5494ee460de6182ff5e0fe99257e80.jpg"]; NSData*data1 =[nsdata datawithcontentsofurl:url1]; Image1=[UIImage imagewithdata:data1]; }); //3. Download Picture 2__block UIImage *image2 =nil; Dispatch_group_async (group, queue,^{nsurl*URL2 = [nsurl urlwithstring:@"Http://su.bdimg.com/static/superplus/img/logo_white_ee663702.png"]; NSData*DATA2 =[nsdata datawithcontentsofurl:url2]; Image2=[UIImage imagewithdata:data2]; }); //4. Merge Pictures (ensure that all tasks within the group are executed, and then execute the block inside the Notify Function)Dispatch_group_notify (group, queue, ^{ //to Open a bitmap contextUigraphicsbeginimagecontextwithoptions (image1.size, NO,0.0); //draw the 1th pictureCGFloat image1w =image1.size.width; CGFloat image1h=image1.size.height; [image1 Drawinrect:cgrectmake (0,0, image1w, image1h)]; //draw the 2nd pictureCGFloat image2w = Image2.size.width *0.5; CGFloat image2h= Image2.size.height *0.5; CGFloat image2y= image1h-image2h; [image2 Drawinrect:cgrectmake (0, image2y, image2w, image2h)]; //get the picture in contextUIImage *fullimage =Uigraphicsgetimagefromcurrentimagecontext (); //End ContextUigraphicsendimagecontext (); //5. Go back to the main thread to display the pictureDispatch_async (dispatch_get_main_queue (), ^{self.imageView.image=fullimage; }); });}- (void) test2{//Asynchronous DownloadDispatch_async (dispatch_get_global_queue (dispatch_queue_priority_default,0), ^{ //1. Download the 1th oneNsurl *URL1 = [nsurl urlwithstring:@"http://g.hiphotos.baidu.com/image/pic/item/f2deb48f8c5494ee460de6182ff5e0fe99257e80.jpg"]; NSData*data1 =[nsdata datawithcontentsofurl:url1]; Self.image1=[UIImage imagewithdata:data1]; [self bindimages]; }); Dispatch_async (dispatch_get_global_queue (dispatch_queue_priority_default,0), ^{ //2. Download the 2nd oneNsurl *url2 = [nsurl urlwithstring:@"Http://su.bdimg.com/static/superplus/img/logo_white_ee663702.png"]; NSData*DATA2 =[nsdata datawithcontentsofurl:url2]; Self.image2=[UIImage imagewithdata:data2]; [self bindimages]; });}- (void) bindimages{if(self.image1 = = Nil | | self.image2 = NIL)return; //3. Merging pictures//to Open a bitmap contextUigraphicsbeginimagecontextwithoptions (self.image1.size, NO,0.0); //draw the 1th pictureCGFloat image1w =self.image1.size.width; CGFloat image1h=self.image1.size.height; [self.image1 Drawinrect:cgrectmake (0,0, image1w, image1h)]; //draw the 2nd pictureCGFloat image2w = Self.image2.size.width *0.5; CGFloat image2h= Self.image2.size.height *0.5; CGFloat image2y= image1h-image2h; [self.image2 Drawinrect:cgrectmake (0, image2y, image2w, image2h)]; //get the picture in contextUIImage *fullimage =Uigraphicsgetimagefromcurrentimagecontext (); //End ContextUigraphicsendimagecontext (); //4. Go back to the main thread to display the pictureDispatch_async (dispatch_get_main_queue (), ^{self.imageView.image=fullimage; });}- (void) test1{//Asynchronous DownloadDispatch_async (dispatch_get_global_queue (dispatch_queue_priority_default,0), ^{ //1. Download the 1th oneNsurl *URL1 = [nsurl urlwithstring:@"http://g.hiphotos.baidu.com/image/pic/item/f2deb48f8c5494ee460de6182ff5e0fe99257e80.jpg"]; NSData*data1 =[nsdata datawithcontentsofurl:url1]; UIImage*image1 =[UIImage imagewithdata:data1]; //2. Download the 2nd oneNsurl *url2 = [nsurl urlwithstring:@"Http://su.bdimg.com/static/superplus/img/logo_white_ee663702.png"]; NSData*DATA2 =[nsdata datawithcontentsofurl:url2]; UIImage*image2 =[UIImage imagewithdata:data2]; //3. Merging pictures//to Open a bitmap contextUigraphicsbeginimagecontextwithoptions (image1.size, NO,0.0); //draw the 1th pictureCGFloat image1w =image1.size.width; CGFloat image1h=image1.size.height; [image1 Drawinrect:cgrectmake (0,0, image1w, image1h)]; //draw the 2nd pictureCGFloat image2w = Image2.size.width *0.5; CGFloat image2h= Image2.size.height *0.5; CGFloat image2y= image1h-image2h; [image2 Drawinrect:cgrectmake (0, image2y, image2w, image2h)]; //get the picture in contextUIImage *fullimage =Uigraphicsgetimagefromcurrentimagecontext (); //End ContextUigraphicsendimagecontext (); //4. Go back to the main thread to display the pictureDispatch_async (dispatch_get_main_queue (), ^{self.imageView.image=fullimage; }); });}@end</pre>Ios-queue Group

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