如何在Swift中拆分UIView的背景色？

class CustomView: UIView {
    // 自定义视图的代码
}

class CustomView: UIView {
    let backgroundView = UIView()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupBackgroundView()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupBackgroundView()
    }

    private func setupBackgroundView() {
        backgroundView.frame = bounds
        backgroundView.backgroundColor = .red // 设置背景色
        addSubview(backgroundView)
    }
}

class CustomView: UIView {
    let backgroundView = UIView()
    let splitView = UIView()

    override init(frame: CGRect) {
        super.init(frame: frame)
        setupBackgroundView()
        setupSplitView()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        setupBackgroundView()
        setupSplitView()
    }

    private func setupBackgroundView() {
        backgroundView.frame = bounds
        backgroundView.backgroundColor = .red // 设置背景色
        addSubview(backgroundView)
    }

    private func setupSplitView() {
        splitView.frame = CGRect(x: bounds.width / 2, y: 0, width: bounds.width / 2, height: bounds.height)
        splitView.backgroundColor = .blue // 设置背景色
        addSubview(splitView)
    }
}