如何以像素为单位设置 UIVIew 的宽度和高度？

Question

I am working on an ObjectiveC app in which I need to set the width and height of a uiview in pixels and than scale that uiview equal to the devices width. The width and height values in pixels are fixed ( let say 900 px x 500 px).

Currently I am doing this,

    UIScreen* mainScreen = [UIScreen mainScreen];

    CGRect frame = CGRectMake(0, 0, 900.0, 500.0);
    [view setFrame:frame];
    CGFloat valScale = mainScreen.bounds.size.width/900.0;
    [view setContentScaleFactor:valScale];

But this is not giving me the desired values.

What should I do?

(PS) Does view.frame.size.width return the width in pixels or points?

Answer 1

Hi for scaling a view you can use the transform property. Say you wish to scale your UIView by a factor of 2 then you can use.

self.view.transform = CGAffineTransformScale(CGAffineTransformIdentity, 2, 2);

CGRect width and height returns points not pixels. One point has two pixels for 2x devices like iPhone 6,7 and three pixels for 3x devices like iPhone 6 Plus,7 Plus.

For more detail you can refer this Apple's documentation link.