iOS application development: Small artboard Demo

There are a lot of features can be added, note here to save slowly add it.

Code section

TouchView.h

#import <UIKit/UIKit.h>    
        
@interface touchview:uiview    
{    
    nsmutablearray *points;    
    Nsarray *points_all;    
    Cgcontextref context;    
    Uicolor *paint_clr;    
}    
@property (strong,nonatomic) Nsmutablearray *points;    
@property (strong,nonatomic) Nsarray *points_all;    
@property (strong,nonatomic) Uicolor *paint_clr;    
        
@end

touchview.m

#import "TouchView.h" @implementation Touchview @synthesize points, Points_all, PAINT_CLR;    
    -(ID) initWithFrame: (CGRect) frame {self = [super Initwithframe:frame];    
    if (self) {//initialization code PAINT_CLR = [Uicolor Greencolor];    
return self;    
//Only override Drawrect:if for you perform custom drawing.    
An empty implementation adversely affects performance during. -(void) DrawRect: (cgrect) Rect {//Drawing code if (!self.points) | | (Self.points.count < 2))    
    {return;    
    context = Uigraphicsgetcurrentcontext ();    
    Set Brush thickness cgcontextsetlinewidth (context, 5.0f);    
    Set the brush color//[[uicolor bluecolor]set];    
    [PAINT_CLR set];    
    Cgcontextsetstrokecolorwithcolor (context, [[Uicolor Bluecolor]cgcolor]); Cgcontextsetstrokecolorwithcolor (context, [PAINT_CLR Cgcolor]); Draw the previous trajectory for (int j = 0; J < [Self.points_all Count]; j +) {Nsmutablearray *points_tmp = [Points_    
                    
            All Objectatindex:j]; for (int i = 0;i < [points_tmp count]-1;i++) {cgpoint point1 = [[Points_tmp Object    
                ATINDEX:I] Cgpointvalue];    
                Cgpoint Point2 = [[Points_tmp objectatindex: (i+1)] cgpointvalue];    
                Cgcontextmovetopoint (context, point1.x, point1.y);    
                Cgcontextaddlinetopoint (context, point2.x, point2.y);    
            Cgcontextstrokepath (context); ///Draw this for (int i=0 i < [self.points count]-1; i++) {Cgpoint    
        Point1 = [[Self.points objectatindex:i] cgpointvalue];    
        Cgpoint Point2 = [[Self.points objectatindex: (i+1)] cgpointvalue];    
        Cgcontextmovetopoint (context, point1.x, point1.y); CgcontextAddlinetopoint (context, point2.x, point2.y);    
    Cgcontextstrokepath (context);    
Multi-point touch-(BOOL) ismultipletouchenabled {return no; //Create an array and record the initial ponit-(void) Touchesbegan: (Nsset *) touches withevent: (Uievent *) Event {s    
    Elf.points = [Nsmutablearray array];    
    Cgpoint pt = [[Touches anyobject] locationinview:self];    
[Self.points Addobject:[nsvalue valuewithcgpoint:pt]]; These points//call Setneedsdisplay are recorded in the//move process, triggering the invocation of the DrawRect Method-(void) touchesmoved: (Nsset *) touches withe    
    Vent: (Uievent *) event {Cgpoint pt = [[Touches anyobject] locationinview:self];    
    [Self.points Addobject:[nsvalue valuewithcgpoint:pt]];    
[Self setneedsdisplay]; }-(void) touchesended: (Nsset *) touches withevent: (Uievent *) event {Nsmutablearray = [    
    Nsmutablearray alloc] initWithArray:self.points]; if (Self.points_all = = Nil) {Self.points_all = [[Nsarray alloc] initwithobjects:points_tmp, nil];    
    }else {self.points_all = [Self.points_all arraybyaddingobject:points_tmp]; }} @end