用segue传递UIImage

Question

我想用两个视图传递两个视图之间的UIImage。问题是我的UIImage在第二个视图控制器中显示为白色。

segue：

var screenShot = UIImage()

override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
    if (segue.identifier == "screenshotEmbed") {
        let svc = segue.destinationViewController as! screenshotViewController
        svc.toPass = self.screenshot
    }

secondViewController：

class screenshotViewController: UIViewController {

@IBOutlet var screenshotView: UIImageView!
var toPass = UIImage()

override func viewDidLoad() {
    super.viewDidLoad()
    self.screenshotView.image = self.toPass        
}

}

我的UIImage只是一个截图，这里的功能是：

func captureScreen() -> UIImage {
    var window: UIWindow? = UIApplication.sharedApplication().keyWindow
    window = UIApplication.sharedApplication().windows[0]
    UIGraphicsBeginImageContextWithOptions(window!.frame.size, window!.opaque, 0.0)
    window!.layer.renderInContext(UIGraphicsGetCurrentContext()!)
    let image = UIGraphicsGetImageFromCurrentImageContext()
    UIGraphicsEndImageContext()
    return image;
}

EDIT。屏幕截图存储在按钮上：

@IBAction func photoAction(sender: AnyObject) {
    self.screenShot = captureScreen()
}

我尝试过很多东西但仍然空白（不是空的，因为记忆地址很好）。

Answer 1

不确定您的screenshotImage对象是否有图片。

我尝试了以下代码并且工作正常。

import UIKit

class ViewController: UIViewController {

    override func prepareForSegue(segue: UIStoryboardSegue, sender: AnyObject?) {
        if (segue.identifier == "screenshotEmbed") {
            let svc = segue.destinationViewController as! ScreenshotViewController
            svc.toPass = captureScreen()
        }
    }

    func captureScreen() -> UIImage {
        var window: UIWindow? = UIApplication.sharedApplication().keyWindow
        window = UIApplication.sharedApplication().windows[0]
        UIGraphicsBeginImageContextWithOptions(window!.frame.size, window!.opaque, 0.0)
        window!.layer.renderInContext(UIGraphicsGetCurrentContext()!)
        let image = UIGraphicsGetImageFromCurrentImageContext()
        UIGraphicsEndImageContext()
        return image;
    }

}

使用此代码的结果：

项目Sample了解更多信息。

Answer 2

在第二个场景中，你应该将属性修改为

<%= f.input :completed, as: :boolean %>

因为在第二个场景中，您将图像初始化为UIImage（）