objective-c – CGAffineTransformMakeScale使UIView在缩放之前跳转到原始大小

我有一个UIView,我设置来响应捏捏手势和改变它的大小,除了,一旦你放大,然后再试一次,它跳转到原来的大小(这恰好是100×200).这是代码：

@implementation ChartAxisView


- (id)initWithFrame:(CGRect)frame {
    if ((self = [super initWithFrame:frame])) {
        // do gesture recognizers
        UIPinchGestureRecognizer *pinch = [[UIPinchGestureRecognizer alloc] initWithTarget:self action:@SELEctor(onPinch:)]; 
        [self addGestureRecognizer:pinch]; 
        [pinch release];
    }
    return self;
}

- (void)drawRect:(CGRect)rect {
    CGContextRef context = UIGraphicsGetCurrentContext();

    CGColorRef redColor = [UIColor colorWithRed:1.0 green:0.0 blue:0.0 alpha:1.0].CGColor;

    CGContextSetFillColorWithColor(context,redColor);
    CGContextFillRect(context,self.bounds);
}

- (void)onPinch: (UIPinchGestureRecognizer*) gesture {  
    self.transform = CGAffineTransformMakeScale(gesture.scale,gesture.scalE);
}

- (void)dealloc {
    [super dealloc];
}


@end

有什么想法吗？