Question

我正致力于UIView上的数字签名。我通常通过此代码创建它，但是我无法在按钮单击时删除bezier路径。单击按钮时未创建新的BezierPath。我正在分享我的代码，请查看我的代码。

       //Create Class for UIView
        #import "SignView.h"
        {
            UIBezierPath *path;
        }
        - (id)initWithCoder:(NSCoder *)aDecoder
        {
            if (self = [super initWithCoder:aDecoder])
            {
                [self setMultipleTouchEnabled:NO];
                [self setBackgroundColor:[UIColor whiteColor]];
                path = [UIBezierPath bezierPath];
                [path setLineWidth:2.0];
            }
            return self;
        }

        - (void)drawRect:(CGRect)rect 
        {
            [[UIColor blackColor] setStroke];
            [path stroke];
        }
        - (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event
        {
            UITouch *touch = [touches anyObject];
            CGPoint p = [touch locationInView:self];
            [path moveToPoint:p];
        }
        - (void)touchesMoved:(NSSet *)touches withEvent:(UIEvent *)event
        {
            UITouch *touch = [touches anyObject];
            CGPoint p = [touch locationInView:self];
            [path addLineToPoint:p];
            [self setNeedsDisplay];
        }
        - (void)touchesEnded:(NSSet *)touches withEvent:(UIEvent *)event
        {
            [self touchesMoved:touches withEvent:event];
        }
        - (void)touchesCancelled:(NSSet *)touches withEvent:(UIEvent *)event
        {
            [self touchesEnded:touches withEvent:event];
        }
        - (void)erase
        {
            path = nil;
            path = [UIBezierPath bezierPath];
            [path setLineWidth:2.0];
            [self setNeedsDisplay];

        }

        //viewController.m

        - (IBAction)clearSign:(id)sender {
            SignView *clrView = [[SignView alloc]init];
            [clrView erase];
        }

Answer 1

请将擦除方法改为以下：

- (void)erase
        {
            [path removeAllPoints];
            path = [UIBezierPath bezierPath];
            [path setLineWidth:2.0];
            [self setNeedsDisplay];

        }

要使删除功能起作用，您可以使用以下appocahes：

方法1

如果您要按代码加载签名视图，请使用以下代码：

//ViewController.m

    #import "SignView.h "

    @interface MySignatureViewController : UIViewController {
         SignView* signView;
    }

    -(void)viewDidLoad{
         signView= [[ mySmoothLineView alloc] initWithFrame: desiredFrame];
         [signView setBackgroundColor:[UIColor clearColor]];
         [self.view addSubview: signView];
    }

     - (IBAction)clearSign:(id)sender {
                [signView erase];
            }

方法2

如果您使用的是storyboard

//ViewController.m


        #import "SignView.h "

        @interface MySignatureViewController : UIViewController {
             @property (nonatomic, weak)SignView* signView;
        }



         - (IBAction)clearSign:(id)sender {
                    [self.signView erase];
                }

删除UIBezierPath绘图？

1 个答案: