如何在 swift 中动态设置帧？

Question

我正在尝试将 imageview 设置为 scrollview.for 的子视图，我设置不同的框架取决于屏幕尺寸。

这是我的代码

 let screensize:CGRect=UIScreen.mainScreen().bounds
        let screenwidth=screensize.width
        var frames:CGRect
        for var index=0 ;index < arrBirds.count ;index++
            {
                if(screenwidth==320)
                {
                    frames.origin.x = CGFloat(index) * (self.view.frame.size.width);
                    frames.origin.y = 0;

                    frames.size=scrollview.frame.size;

                }
                else if(screenwidth==375)
                {
                    frames.origin.x = CGFloat(index) * (self.view.frame.size.width);
                    frames.origin.y=0;
                    frames.size=scrollview.frame.size;
                }
                else
                {
                    frames.origin.x = CGFloat(index) * (self.view.frame.size.width);
                    frames.origin.y=0;
                    frames.size=scrollview.frame.size;
                }

                imageView=UIImageView(frame:frames)
                imageView.image=UIImage(named: arrBirds[index] as! String)
                scrollview .addSubview(imageView)

但是我在这行遇到错误

  frames.origin.x = CGFloat(index) * (self.view.frame.size.width);//struct frame must be completely initialised  before a member is stored to.

Answer 1

您还没有创建结构 CGRect 的实例。在访问/设置任何成员之前，您需要先创建一个实例，然后仅在那之后设置它的不同成员：

将行 var frames:CGRect 更改为：

var frames = CGRectZero

Answer 2

根据Apple Docs：

Classes and structures must set all of their stored properties to an appropriate initial value by the time an instance of that class or structure is created.

您的 frames 对象未初始化，您应该这样写：

var frames = CGRectZero

如何在 swift 中动态设置帧？

how to set frame dynamically in swift?

ios

cgrect

swift