iOS rewrite DrawRect method implements a view with arrows

Create a subclass of UIView, overriding the DrawRect method to implement an irregular-shaped view, which provides an implementation code with an arrow view:

ArrowView.h

#import <UIKit/UIKit.h>@interface  arrowview:uiview@end

arrowview.m

#import "ArrowView.h"@implementationArrowview/*//Only override drawrect:if your perform custom drawing.//an empty implementation adversely affects performance Duri ng animation.-(void) DrawRect: (cgrect) Rect {//Drawing code}*/-(instancetype) init{ Self=[Super Init]; if(self) {Self.backgroundcolor=[Uicolor Whitecolor]; }    returnSelf ; }-(Instancetype) initWithFrame: (cgrect) frame{ Self=[Super Initwithframe:frame]; if(self) {Self.backgroundcolor=[Uicolor Whitecolor]; }    returnSelf ; }- (void) DrawRect: (CGRect) rect{[Super Drawrect:rect]; NSLog (@"being DrawRect ..."); //gets the graph of the current drawing that the view pushes into the stack, which is equivalent to the drawing you want to drawCgcontextref CTX =Uigraphicsgetcurrentcontext (); //[[Uicolor Whitecolor]Set]; //Create a new empty graphics pathCgcontextbeginpath (CTX); NSLog (@"Start drawing ..."); //starting position coordinatesCGFloat origin_x =rect.origin.x; CGFloat origin_y=Ten;//FRAME.ORIGIN.Y + 10; //position coordinates of the first lineCGFloat line_1_x = rect.size.width- -; CGFloat line_1_y=origin_y; //position coordinates of the second lineCGFloat line_2_x = line_1_x +5; CGFloat line_2_y=RECT.ORIGIN.Y; //position coordinates of the third lineCGFloat line_3_x = line_2_x +5; CGFloat line_3_y=line_1_y; //position coordinates of the fourth lineCGFloat line_4_x =Rect.size.width; CGFloat line_4_y=line_1_y; //position coordinates of the fifth lineCGFloat line_5_x =Rect.size.width; CGFloat line_5_y=Rect.size.height; //position coordinates of the sixth lineCGFloat line_6_x =origin_x; CGFloat line_6_y=Rect.size.height;        Cgcontextmovetopoint (CTX, origin_x, origin_y);    Cgcontextaddlinetopoint (CTX, line_1_x, line_1_y);    Cgcontextaddlinetopoint (CTX, line_2_x, line_2_y);    Cgcontextaddlinetopoint (CTX, line_3_x, line_3_y);    Cgcontextaddlinetopoint (CTX, line_4_x, line_4_y);    Cgcontextaddlinetopoint (CTX, line_5_x, line_5_y);        Cgcontextaddlinetopoint (CTX, line_6_x, line_6_y);        Cgcontextclosepath (CTX); //Set Fill ColorUicolor *customcolor = [Uicolor colorwithwhite:0Alpha0.8];    Cgcontextsetfillcolorwithcolor (CTX, Customcolor.cgcolor); Cgcontextfillpath (CTX);}@end

Then call in Viewcontroller to see the results

Viewcontroller.m

#import "ViewController.h"#import "ArrowView.h"@interfaceViewcontroller ()@end@implementationViewcontroller- (void) viewdidload {[Super viewdidload]; //additional setup after loading the view, typically from a nib.NSLog (@"begin ..."); Arrowview*view = [[Arrowview alloc] Initwithframe:cgrectmake ( -, -, $, the)]; //[view Setbackgroundcolor:[uicolor Orangecolor];[Self.view Addsubview:view]; NSLog (@"End ...");}- (void) didreceivememorywarning {[Super didreceivememorywarning]; //Dispose of any resources the can be recreated.}@end

Results:

Console Print Results:

The thread ID of the console print is the same, stating that the DrawRect method is called on the main thread.

iOS rewrite DrawRect method implements a view with arrows