Simple Concentric circle effect

1 #import "BNRHypnosisView.h"2 3 @implementationBnrhypnosisview4-(Instancetype) initWithFrame: (CGRect) Frame5 {6Self =[Super Initwithframe:frame];7     if(self)8     {9Self.backgroundcolor =[Uicolor Clearcolor];Ten     } One     returnSelf ; A } -- (void) DrawRect: (cgrect) Rect - { theCGRect bounds =self.bounds; -      -     //According to Bounds Computing center point - Cgpoint Center; +center.x = bounds.origin.x + bounds.size.width/2.0; -CENTER.Y = bounds.origin.y + bounds.size.height/2.0; +      A     //calculates the radius of a circle based on the lesser values of the wide chart and high schools at //Float radius = (MIN (bounds.size.width, Bounds.size.height))/2.0; -      -     //make the outermost circle a circumscribed circle of the view -     floatMaxradius = Hypot (bounds.size.width, bounds.size.height)/2.0; -      -     //This object is used to draw lines or curves, which make up various shapes.  inUibezierpath *path =[[Uibezierpath alloc]init]; -     //center point, radius value is radius, defines a path from 0 to M_pi *2.0 radians (full circle) to //[Path Addarcwithcenter:center + //Radius:radius - //startangle:0.0 the //ENDANGLE:M_PI * 2.0 * //Clockwise:yes]; $     Panax Notoginseng      for(floatCurrentradius = Maxradius; Currentradius >0; Currentradius-= -) -     { the      //The original concentric circle produces a handwriting that appears when it is drawn and needs to be removed +[Path moveToPoint: (Cgpoint) {center.x +currentradius,center.y}]; A [Path Addarcwithcenter:center the Radius:currentradius +StartAngle:0.0 -endangle:m_pi*2.0 $ Clockwise:yes]; $     } -      -     //set the line width to 10 points thePath.linewidth =Ten; -     Wuyi     //set paint color to light gray the [[Uicolor Redcolor] setstroke]; -      Wu [path stroke]; -}

Simple Concentric circle effect