将图片对齐到屏幕底层

Question

设置一个图片水平居中，位于屏幕的最底层。好像只要设置y坐标为screen_height - image_height就可以。

UIImage *img = [UIImage imageNamed:@"my-image.png"];
UIImageView *imgView = [[UIImageView alloc]initWithImage:img];
imgView.frame = CGRectMake(0, 0, img.size.width / 2, img.size.height / 2);

CGRect screenBounds = [[UIScreen mainScreen] bounds];
CGFloat screenScale = [[UIScreen mainScreen] scale];
CGSize screenSize = CGSizeMake(screenBounds.size.width * screenScale, screenBounds.size.height * screenScale);

CGRect frame = imgView.frame;
frame.origin.x = 0;
frame.origin.y = screenSize.height - img.size.height;
imgView.frame = frame;

[self.view addSubview:imgView];

但不知为什么没实现？ 0,0 是屏幕的左上角。所以screen_height - image_height应该对啊，请前辈解答。不胜感激

Answer 1

CGSize screenSize = CGSizeMake(screenBounds.size.width * screenScale, screenBounds.size.height * screenScale);

这是何意? 屏幕的尺寸应该是这样取吧

CGRect screenBounds = [[UIScreen mainScreen] bounds];
CGSize screenSize =screenBounds.size;
NSLog(@"screen size :%@",NSStringFromCGSize(screenSize));

这样再去计算试试,如果要去掉statusbar, 还有navigationbar的话

frame.origin.y = screenSize.height- 20 - 44 - img.size.height;