iPhone SDK-UIImageView : position of image

Question

我有一个标准的 UIImageView，其 ContentMode 设置为 UIContentModeAspectRatioFit。 我试图找出如何获取图像相对于绝对坐标或 UIImageView 原点的位置。

这可能吗？我看过很多关于无法设置位置的帖子，但没有关于是否可以GET位置的帖子。

非常感谢， 布雷特

Answer 1

我知道这个问题已经得到解答，但我写了一个函数来计算 imageView 中图像相对于 imageView 的帧。

编辑:忘了最重要的。

+ (CGRect) imagePositionInImageView:(UIImageView*)imageView
{
    float x = 0.0f;
    float y = 0.0f;
    float w = 0.0f;
    float h = 0.0f;
    CGFloat ratio = 0.0f;
    CGFloat horizontalRatio = imageView.frame.size.width / imageView.image.size.width;
    CGFloat verticalRatio = imageView.frame.size.height / imageView.image.size.height;

    switch (imageView.contentMode) {
        case UIViewContentModeScaleToFill:
            w = imageView.frame.size.width;
            h = imageView.frame.size.height;
            break;
        case UIViewContentModeScaleAspectFit:
            // contents scaled to fit with fixed aspect. remainder is transparent
            ratio = MIN(horizontalRatio, verticalRatio);
            w = imageView.image.size.width*ratio;
            h = imageView.image.size.height*ratio;
            x = (horizontalRatio == ratio ? 0 : ((imageView.frame.size.width - w)/2));
            y = (verticalRatio == ratio ? 0 : ((imageView.frame.size.height - h)/2));
            break;
        case UIViewContentModeScaleAspectFill:
            // contents scaled to fill with fixed aspect. some portion of content may be clipped.
            ratio = MAX(horizontalRatio, verticalRatio);
            w = imageView.image.size.width*ratio;
            h = imageView.image.size.height*ratio;
            x = (horizontalRatio == ratio ? 0 : ((imageView.frame.size.width - w)/2));
            y = (verticalRatio == ratio ? 0 : ((imageView.frame.size.height - h)/2));
            break;
        case UIViewContentModeCenter:
            // contents remain same size. positioned adjusted.
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            x = (imageView.frame.size.width - w)/2;
            y = (imageView.frame.size.height - h)/2;
            break;
        case UIViewContentModeTop:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            x = (imageView.frame.size.width - w)/2;
            break;
        case UIViewContentModeBottom:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            y = (imageView.frame.size.height - h);
            x = (imageView.frame.size.width - w)/2;
            break;
        case UIViewContentModeLeft:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            y = (imageView.frame.size.height - h)/2;
            break;
        case UIViewContentModeRight:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            y = (imageView.frame.size.height - h)/2;
            x = (imageView.frame.size.width - w);
            break;
        case UIViewContentModeTopLeft:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            break;
        case UIViewContentModeTopRight:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            x = (imageView.frame.size.width - w);
            break;
        case UIViewContentModeBottomLeft:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            y = (imageView.frame.size.height - h);
            break;
        case UIViewContentModeBottomRight:
            w = imageView.image.size.width;
            h = imageView.image.size.height;
            y = (imageView.frame.size.height - h);
            x = (imageView.frame.size.width - w);
        default:
            break;
    }
    return CGRectMake(x, y, w, h);
}