混淆cocoa问题“程序挂起,除非存在未识别的方法调用

请原谅,这件事很难解释。我希望外面的英雄知道这里发生了什么。需要一些历史;

我的一个可可物体,球代表一个小图形。它只在视图中有意义。在Ball的一些方法中,它要求视图重新绘制。最重要的是,它要求视图在设置Ball_s position参数时重新绘制。这是在设定器中实现的。

这里是一口,建议:

鉴于M

- (void)mouseUp:(NSEvent *)theEvent {
    if (![runnerPath isEmpty]) {
        [walkPath removeAllPoints];
        [walkPath appendBezierPath:runnerPath];
        [runnerPath removeAllPoints];

        [[self held] setStep:0];
        [[self held] setPath:walkPath];
        [NSTimer scheduledTimerWithTimeInterval:.01 target:[self held] selector:@selector(pace) userInfo:nil repeats:YES];

        }
}

在球上

 - (void)pace { 
    CGFloat juice = 10;
    BOOL loop = YES;

    while (loop) {
        if ([self step] == [[self path] elementCount]) {
            if ([[self timer] isValid]) {
                [[self timer] invalidate];
            }
            [[self path] removeAllPoints];
//          @throw([NSException exceptionWithName:@"test" reason:@"reason" userInfo:nil]);
        }

        if (loop) {
            CGFloat distance;
            NSPoint stepPoint;

            if ([[self path] elementCount] > 0) {
                NSPoint returnPoints[2];
                [[self path] elementAtIndex:[self step] associatedPoints:returnPoints];
                stepPoint = returnPoints[0];
                distance = pixelDistance([self position], stepPoint);
            }

            if (distance <= juice) {
                [self setPosition:stepPoint];
                if (distance < juice) {
                    juice -= distance;
                    loop = YES;
                    [self setStep:[self step]+1];
                } else {
                    loop = NO;
                }
            } else {            
                NSPoint cutPoint = moveAlongBetween([self position], stepPoint, juice);
                [self setPosition:cutPoint];

                loop = NO;
            }

        }
    }

}