如何在 UIViewController 中访问由 UIView 的子类创建的对象

How to access an object created by a subclass of UIView in a UIViewController

我的视图控制器中有一个 UIView 的子类,它通过手指触摸绘制 UIBezierPath:

#import "LinearInterpView.h"

@implementation LinearInterpView
{
    UIBezierPath *path;
}

- (id)initWithCoder:(NSCoder *)aDecoder
{
    if (self = [super initWithCoder:aDecoder])
    {
        [self setMultipleTouchEnabled:NO];
        [self setBackgroundColor:[UIColor colorWithWhite:0.9 alpha:1.0]];
        path = [UIBezierPath bezierPath];
        [path setLineWidth:2.0];

        // Add a clear button
        UIButton *clearButton = [[UIButton alloc] initWithFrame:CGRectMake(10.0, 10.0, 80.0, 40.0)];
        [clearButton setTitle:@"Clear" forState:UIControlStateNormal];
        [clearButton setBackgroundColor:[UIColor lightGrayColor]];
        [clearButton addTarget:self action:@selector(clearSandBox) forControlEvents:UIControlEventTouchUpInside];
        [self addSubview:clearButton];

    }
    return self;
}

- (void)drawRect:(CGRect)rect
{
    [[UIColor darkGrayColor] 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];
}

@end

这里一切正常,但我需要在我的视图控制器中访问 finger 生成的路径并分析它。当我调试代码时,我可以在视图控制器中的 UIView 中看到变量 path,但我无法以编程方式访问它。有什么方法可以访问子类创建的对象吗?

要访问 viewController 的路径,您必须将其定义为 Public 变量并通过 class.

外部访问它

将您的 : UIBezierPath *path; 定义到 @interface 文件中并将其访问到 ViewController

@interface LinearInterpView
{
    UIBezierPath *path;
}

喜欢 :

LinearInterpView  *viewLinner = [LinearInterpView alloc]initwithframe:<yourFrame>];

//By This line you can access path into your view controller.
viewLinner.path 

您也可以创建该视图的 IBOutlet 并像上面一样访问。

谢谢。