如何在 Swift 2.0 中获得正确的 UIView 大小或边界？

Question

您好，我无法将渐变颜色应用到我的UIView。它正确应用，但颜色边界因水平和纵向方向而异。

如果我在纵向方向上正确设置，那么当我将设备翻转到水平方向时，渐变视图的边界不会改变。

那么，如何为水平和纵向设备方向获得正确的约束和UIView 的大小？

非常感谢您的帮助！！！

我尝试过的代码：

import UIKit

class ViewController: UIViewController {


    @IBOutlet var viewBar: UIView!


    override func viewDidLoad() {
        super.viewDidLoad()

        viewBar.layer.shadowOpacity = 0.5
        viewBar.layer.shadowOffset = CGSize(width: 3.0, height:2.0)
        viewBar.layer.shadowRadius = 5.0
        viewBar.layer.shadowColor = UIColor.blueColor().CGColor

        let gradient: CAGradientLayer = CAGradientLayer()

        gradient.colors = [UIColor.blueColor().CGColor, UIColor.redColor().CGColor]
        gradient.locations = [0.0 , 1.0]
        gradient.startPoint = CGPoint(x: 0.0, y: 1.0)
        gradient.endPoint = CGPoint(x: 1.0, y: 1.0)
        gradient.frame.size = self.viewBar.bounds.size

        self.viewBar.layer.insertSublayer(gradient, atIndex: 0)

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()

    }


}

编码输出：

Answer 1

在viewDidLoad 中，布局尚未发生，因此您输入了错误的框架，请将gradient.frame.size = self.viewBar.bounds.size 移动到viewDidLayoutSubviews: 或viewWillAppear:，以便您的gradient 获得正确的框架。

  override func viewDidLayoutSubviews() {
    gradient.frame.size = self.viewBar.bounds.size
  }

Answer 2

使用此方法在 viewDidLayoutSubViews 中检查您的设备方向。

+(NSString*)checkDeviceOrientation
{
    NSString *deviceOrientation;

    if ([[UIDevice currentDevice]orientation]== UIInterfaceOrientationLandscapeLeft ) {

        deviceOrientation = @"landscape left mode";
    }
    else if ([[UIDevice currentDevice]orientation]==UIInterfaceOrientationLandscapeRight){
        deviceOrientation = @"landscape right mode";
    }
    else{
        deviceOrientation = @"potrait mode";
    }
    return deviceOrientation;
}

然后在 viewDidLayoutSubviews 像这样调用这个函数，

-(void)viewDidLayoutSubview
{
if(IS_PHONE4)
if([self.checkDeviceOrientation isEqualtoString;@"landscape right mode"])
{
   NSLog(@"Get your view size%@",self.view.frame.size.width);
}

if(IS_IPHONE5)
if([self.checkDeviceOrientation isEqualtoString;@"landscape right mode"])
{
   NSLog(@"Get your view size%@",self.view.frame.size.width);
}
.....

}

还记得把这些常量放在你想要的任何文件中。

#define IS_IPAD             (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPad)
#define IS_IPHONE           (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone)
#define IS_IPHONE4          (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 480.0f || IS_IPHONE && [[UIScreen mainScreen]bounds].size.width == 480.0f)
#define IS_IPHONE5          (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 568.0f || IS_IPHONE && [[UIScreen mainScreen]bounds].size.width == 568.0f)
#define IS_IPHONE6          (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 667.0 || IS_IPHONE && [[UIScreen mainScreen]bounds].size.width == 667.0f)
#define IS_IPHONE6PLUS      (IS_IPHONE && [[UIScreen mainScreen] bounds].size.height == 736.0 || IS_IPHONE && [[UIScreen mainScreen]bounds].size.width == 736.0f)
#define IS_RETINA           ([[UIScreen mainScreen] respondsToSelector:@selector(displayLinkWithTarget:selector:)] && ([UIScreen mainScreen].scale == 2.0))

我不熟悉 Swift 代码，但希望对您有所帮助。