在 UIImageView 中应用适合图像的宽高比后如何知道图像大小 [英] How to know the image size after applying aspect fit for the image in an UIImageView

问题描述

我正在将图像加载到模式为Aspect Fit"的图像视图中.我需要知道我的图像被缩放到的大小.请帮忙.

I am loading an image to an imageview with mode as 'Aspect Fit'. I need to know the size to which my image is being scaled to. Please help.

推荐答案

请看@Paul-de-Lange 的回答，而不是这个

我在一个易于访问的变量中找不到任何东西，所以这是蛮力方法:

I couldn't find anything in an easily accessible variable that had this, so here is the brute force way:

- (CGSize) aspectScaledImageSizeForImageView:(UIImageView *)iv image:(UIImage *)im {

float x,y;
float a,b;
x = iv.frame.size.width;
y = iv.frame.size.height;
a = im.size.width;
b = im.size.height;

if ( x == a && y == b ) {           // image fits exactly, no scaling required
    // return iv.frame.size;
}
else if ( x > a && y > b ) {         // image fits completely within the imageview frame
    if ( x-a > y-b ) {              // image height is limiting factor, scale by height
        a = y/b * a;
        b = y;
    } else {
        b = x/a * b;                // image width is limiting factor, scale by width
        a = x;
    }
} 
else if ( x < a && y < b ) {        // image is wider and taller than image view
    if ( a - x > b - y ) {          // height is limiting factor, scale by height
        a = y/b * a;
        b = y;
    } else {                        // width is limiting factor, scale by width
        b = x/a * b;
        a = x;
    }
}
else if ( x < a && y > b ) {        // image is wider than view, scale by width
    b = x/a * b;
    a = x;
}
else if ( x > a && y < b ) {        // image is taller than view, scale by height
    a = y/b * a;
    b = y;
}
else if ( x == a ) {
    a = y/b * a;
    b = y;
} else if ( y == b ) {
    b = x/a * b;
    a = x;
}
return CGSizeMake(a,b);

}

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