小编yac*_*aka的帖子

我看过axios文档，但它说的只是

// Add a request interceptor
axios.interceptors.request.use(function (config) {
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    return Promise.reject(error);
  });

// Add a response interceptor
axios.interceptors.response.use(function (response) {
  // Do something with response data
  return response;
}, function (error) {
  // Do something with response error
  return Promise.reject(error);
});

同样，许多教程仅显示此代码，但是我很困惑它的用途，有人可以给我简单的示例进行操作。

我只是想在我的视图控制器中显示一个简单的渐变.此代码不起作用(视图保持白色).

import UIKit
import QuartzCore

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()

        let ly = CAGradientLayer()
        ly.frame = view.bounds
        ly.colors = [UIColor.orangeColor(), UIColor.blackColor()]
        ly.locations = [0.0, 1.0]
        println(view.bounds) // (0.0, 0.0, 320.0, 568.0)

        view.layer.addSublayer(ly)
    }

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


}

有趣的是,如果我设置ly.backgroundColor为橙色,视图将变为橙色.我们可以得出结论,图层有效地位于视图之上,但渐变无效.