iOS Development _ Picture Doodle

Key code for the host controller:

A viewcontroller.m

#import "ViewController.h"#import "ZRPaintView.h"#import "Uiimage+zr.h"@interfaceViewcontroller ()-(ibaction) clear;-(ibaction) back;-(ibaction) Save; @property (weak, nonatomic) Iboutlet Zrpaintview*Paintview;@end@implementationViewcontroller- (void) viewdidload {[Super viewdidload]; //additional setup after loading the view, typically from a nib.}- (void) didreceivememorywarning {[Super didreceivememorywarning]; //Dispose of any resources the can be recreated.}-(Ibaction) Clear {[Self.paintview clear];}-(ibaction) Back {[Self.paintview back];}-(ibaction) Save {//1UIImage *image =[UIImage CaptureWithView:self.paintView]; //2 Save to pictureUiimagewritetosavedphotosalbum (image, Self, @selector (image:didFinishSavingWithError:contextInfo:), nil); }/** * * @param image Image * @param error error after saving picture operation*/- (voidImage: (UIImage *) image didfinishsavingwitherror: (nserror *) Error ContextInfo: (void*) contextinfo{if(Error) {NSLog (@"Save failed"); }Else{NSLog (@"saved successfully"); }}@end

Two create a subclass that inherits from UIView:

ZRPaintView.h

#import <UIKit/UIKit.h>@interface  zrpaintview:uiview-(void) Clear; -(void) back; @end

zrpaintview.m

#import "ZRPaintView.h"@interfaceZrpaintview () @property (nonatomic,strong) Nsmutablearray*totalpathpoints;//used to record@property (nonatomic,strong) Nsmutablearray *pathpoints;@end@implementationZrpaintview-(Nsmutablearray *) totalpathpoints{if(!_pathpoints) {_pathpoints=[Nsmutablearray array]; }    return_pathpoints;}-(void) clear{[self.totalpathpoints removeallobjects]; [Self setneedsdisplay];}-(void) back{[self.totalpathpoints Removelastobject]; [Self setneedsdisplay];}/** * Determine the starting point*/-(void) Touchesbegan: (Nsset<uitouch *> *) touches withevent: (Uievent *)Event{Uitouch*touch =[touches anyobject]; Cgpoint startpos=[Touch LocationInView:touch.view]; //each time you start to touch, create a new array to hold a bit of this touch (all points in this touch process)Nsmutablearray *pathpoints =[Nsmutablearray array];    [PathPoints Addobject:[nsvalue Valuewithcgpoint:startpos];    [Self.totalpathpoints addobject:pathpoints]; //add all the points in this path to the array[self setneedsdisplay];}/** * Connection*/-(void) touchesmoved: (Nsset<uitouch *> *) touches withevent: (Uievent *)Event{Uitouch*touch =[touches anyobject]; Cgpoint Currentpos=[Touch LocationInView:touch.view]; //Take out the corresponding array of this pathNsmutablearray *pathpoints =[Self.totalpathpoints Lastobject];        [PathPoints Addobject:[nsvalue Valuewithcgpoint:currentpos]; [Self setneedsdisplay];}/** * Connection*/-(void) touchesended: (Nsset<uitouch *> *) touches withevent: (Uievent *)Event{//Uitouch *touch = [touches anyobject];//cgpoint endpos = [Touch LocationInView:touch.view];//    //    //Take out the corresponding array of this path//Nsmutablearray *pathpoints = [self.totalpathpoints lastobject];//[pathpoints addobject:[nsvalue valuewithcgpoint:endpos];//    //[self setneedsdisplay];[Self touchesmoved:touches withevent:Event];}- (void) DrawRect: (cgrect) rect {//Uirectfill (cgrectmake (0, 0, +));Cgcontextref CTX =Uigraphicsgetcurrentcontext ();  for(Nsmutablearray *pathpointsinchself.totalpathpoints) { for(inti =0; i<pathpoints.count; i++) {//a pathCgpoint pos =[pathpoints[i] cgpointvalue]; if(i==0) {cgcontextmovetopoint (CTX, pos.x, POS.Y); }Else{cgcontextaddlinetopoint (CTX, pos.x, POS.Y);    }}} cgcontextsetlinecap (CTX, Kcglinecapround);    Cgcontextsetlinejoin (CTX, Kcglinejoinround); Cgcontextsetlinewidth (CTX,5); Cgcontextstrokepath (CTX);}@end

Three create uiimage classification files:

Uiimage+zr.h

#import <UIKit/UIKit.h>@interface  UIImage (ZR)+ (Instancetype) Capturewithview: ( UIView *) view; @end

Uiimage+zr.m

#import "Uiimage+zr.h"@implementationUIImage (ZR)+ (Instancetype) Capturewithview: (UIView *) view{//1 Open ContextUigraphicsbeginimagecontextwithoptions (View.frame.size, NO,0.0); //2 render the layer of the Controller view to the context[View.layer Renderincontext:uigraphicsgetcurrentcontext ()]; //3 Take out the pictureUIImage *newimage =Uigraphicsgetimagefromcurrentimagecontext (); //4 End ContextUigraphicsendimagecontext (); returnnewimage;}@end

iOS Development _ Picture Doodle