Iphone 如何将图像缩小到滚动视图的中心位置

在我的应用程序中，我需要用cam捕捉图像，然后将其传递给imageView，它用作ScrollView的子视图

要求是图像必须有1/4大小的缩小和3倍大小的放大

现在的问题是，当我缩小这个图像时，图像缩小了，但它没有保持在中心位置。它根据手指的触碰来设置其位置。 没有双击缩放，也不需要

下面是代码

- (void)viewDidLoad 

{ [超级视图下载]

UIImage* tmpImage = nil;
tmpImage = [roomImage resizedImage:imageScrollView.frame.size interpolationQuality:0];
imageView = [[UIImageView alloc] initWithImage:tmpImage];
imageView.contentMode = UIViewContentModeScaleAspectFit;

imageScrollView.delegate = self;
imageScrollView.canCancelContentTouches = NO;
imageScrollView.minimumZoomScale = 0.25;
imageScrollView.maximumZoomScale = 3.00;


imageScrollView.clipsToBounds = YES;

[imageView sizeToFit];
[imageScrollView addSubview:imageView];

imageScrollView.contentSize = imageView.frame.size;
    imageScrollView.contentMode = UIViewContentModeScaleAspectFit;  
    imageScrollView.contentOffset = CGPointMake(imageScrollView.frame.size.width/2, imageScrollView.frame.size.height/2);
imageScrollView.autoresizesSubviews = YES;
imageScrollView.autoresizingMask =  UIViewAutoresizingFlexibleHeight |        UIViewAutoresizingFlexibleWidth   |  
UIViewAutoresizingFlexibleLeftMargin | UIViewAutoresizingFlexibleRightMargin | 
UIViewAutoresizingFlexibleTopMargin | UIViewAutoresizingFlexibleBottomMargin;


CGFloat f,x,y;

if(tmpImage.size.height > tmpImage.size.width)
{
    f = (imageScrollView.frame.size.height/tmpImage.size.height);
}
else
{
    f = (imageScrollView.frame.size.width/tmpImage.size.width);
}

x = (imageScrollView.frame.size.width - tmpImage.size.width*f)/2;
y = (imageScrollView.frame.size.height - tmpImage.size.height*f)/2;

imageView.bounds = CGRectMake(x, y,tmpImage.size.width, tmpImage.size.height);
[imageView setNeedsDisplay];
[imageScrollView setZoomScale:f animated:YES];
[imageScrollView setNeedsDisplay];

jpgPath = nil;
[roomImage release];
roomImage = nil;

}

希望任何人都能帮我

---

提前感谢..，

如果我理解正确，您可以对UIScrollView进行子类化，并在layoutSubviews方法中使用类似于以下的内容，以保持其内容集中：

-(void)layoutSubviews {

[super layoutSubviews];

CGSize boundsSize = self.bounds.size;
CGRect contentViewFrame  = contentView.frame;

if (contentViewFrame.size.width < boundsSize.width) {

    contentViewFrame.origin.x = (boundsSize.width - contentViewFrame.size.width) / 2;

} else {

    contentViewFrame.origin.x = 0;

}

if (contentViewFrame.size.height < boundsSize.height) {

    contentViewFrame.origin.y = (boundsSize.height - contentViewFrame.size.height) / 2;

} else {

    contentViewFrame.origin.y = 0;

}

contentView.frame = contentViewFrame;

}

contentView变量是一个iVar，在您的情况下，它表示您希望在scrollView中显示的imageView。希望这有助于：-