objective-c - 如何在 IOS 中心水平对齐我的图像

Question

这是我的图片:

Obj *obj = ... obj has imageHref which is NSString

UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:obj.imageHref]]; 
[image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];

根据图像大小，我不知道如何将它居中，有什么想法吗？

这都是内部方法:

- (void)drawRect:(CGRect)rect {    
    Obj *obj = ... obj has imageHref which is NSString

    UIImage *image = [UIImage imageNamed:[NSString stringWithFormat:obj.imageHref]]; 
    [image drawInRect:CGRectMake(0, 0, image.size.width, image.size.height)];

    NSLog(@"%f", rect.size.width);
     NSLog(@"%f", rect.size.height);
}

rect.size.width 打印 320.000000 而 rect.size.height 打印 416.000000

Answer 1

[image drawInRect:CGRectMake((self.view.frame.size.width/2) - (image.size.width/2),
                             (self.view.frame.size.height / 2) - (image.size.height / 2),
                             image.size.width, 
                             image.size.height)];

编辑:

因为您已经在 UIView 中:

[image drawInRect:CGRectMake((self.frame.size.width/2) - (image.size.width/2), (self.frame.size.height / 2) - (image.size.height / 2), image.size.width, image.size.height)];