我找到了我想在我的视图控制器中实现的教程,但是代码是用编写的,UIView所以如何将UIView代码转换为UIViewController 它可以在这里工作是我的代码
  #import <UIKit/UIKit.h>
  @interface MyLineDrawingView : UIView {
  UIBezierPath *myPath;
  UIColor *brushPattern;
  }
  @end
   #import "MyLineDrawingView.h"
   @implementation MyLineDrawingView
   - (id)initWithFrame:(CGRect)frame
 {
   self = [super initWithFrame:frame];
    if (self) {
    // Initialization code
    self.backgroundColor=[UIColor whiteColor];
    myPath=[[UIBezierPath alloc]init];
    myPath.lineCapStyle=kCGLineCapRound;
    myPath.miterLimit=0;
    myPath.lineWidth=10;
    brushPattern=[UIColor redColor];
    }
   return self;
   }
drawRect:仅当您执行自定义绘图时才覆盖。空实现会对动画期间的性能产生不利影响。
 - (void)drawRect:(CGRect)rect
 {
 [brushPattern setStroke];
 [myPath strokeWithBlendMode:kCGBlendModeNormal alpha:1.0];
 // Drawing code
 //[myPath stroke];
 }
  #pragma mark - Touch Methods
 -(void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
{
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath moveToPoint:[mytouch locationInView:self]];
}
-(void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event {
UITouch *mytouch=[[touches allObjects] objectAtIndex:0];
[myPath addLineToPoint:[mytouch locationInView:self]];
[self setNeedsDisplay];
}
-(void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
     {
         //handle touch event
      }