创建一个 UIImageView

要以编程方式创建 UIImageView，你需要做的就是创建 UIImageView 的实例：

//Swift
let imageView = UIImageView()

//Objective-C
UIImageView *imageView = [[UIImageView alloc] init];

你可以使用 CGRect 设置 UIImageView 的大小和位置：

//Swift
imageView.frame = CGRect(x: 0, y: 0, width: 200, height: 200)

//Objective-C
imageView.frame = CGRectMake(0,0,200,200);

或者你可以在初始化期间设置大小：

//Swift
UIImageView(frame: CGRect(x: 0, y: 0, width: 200, height: 200))

//Objective-C
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0,200,200);

//Alternative way of defining frame for UIImageView
UIImageView *imageView = [[UIImageView alloc] init];
CGRect imageViewFrame = imageView.frame;
imageViewFrame.size.width = 200;
imageViewFrame.size.height = 200;
imageViewFrame.origin.x = 0;
imageViewFrame.origin.y = 0;
imageView.frame = imageViewFrame;

注意：你必须导入 UIKit 才能使用 UIImageView。