小编Tom*_*m M的帖子

我是学习Swift的新手,我正试图让一个非常简单的应用程序运行.我想要做的就是在按下按钮时让UIView.drawRect更新.它会在应用程序首次加载时更新/绘制,然后在我尝试之后无需更新/绘制.几天来,我一直在反对这一点,我找不到任何帮助.

我建立:

• 单一视图应用程序

• 一个按钮,链接到视图控制器作为动作

• 一个新类,Test_View,子类化UIView

ViewController代码:

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        var f = Test_View()

    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    @IBAction func Button_Pressed(sender: AnyObject) {
        var f = Test_View()
        f.setNeedsDisplay()
        NSLog("Button pressed.")
    }

}

Test_View代码:

class Test_View: UIView {

    override func drawRect(rect: CGRect) {
        let h = rect.height
        let w …