使用XCode 6.1/Swift以编程方式将图像设置为UIImageView

I'm trying to set UIImageView programmatically in XCode 6.1:

我试图在XCode 6.1中以编程方式设置UIImageView:

@IBOutlet weak var bgImage: UIImageView!

var image : UIImage = UIImage(named:"afternoon")!
bgImage = UIImageView(image: image)
bgImage.frame = CGRect(x: 0, y: 0, width: 100, height: 200)
view.addSubview(bgImage)

But Xcode is saying "expected declaration" with bgImage = UIImageView(image: image) Image "afternoon"is a PNG, and my understanding is PNG does not need an extension in XCode 6.1.

但是Xcode说的是bgImage = UIImageView(image: image) image "afternoon"是PNG，我的理解是PNG在Xcode 6.1中不需要扩展。

Also tried just bgImage.image = UIImage(named: "afternoon"), but still get:

也只是bgImage。image = UIImage(命名:"afternoon")，但仍然得到:

UPDATE

更新

OK, I have put the code to update UIImageView into the viewDidLoad function, but UIImageView is still not showing the image (which exists in the base directory as afternoon.png):

好的，我已经将更新UIImageView的代码放到viewDidLoad函数中，但是UIImageView仍然没有显示图像(它在基目录中为afternoon.png):

 @IBOutlet weak var bgImage: UIImageView!
    @IBOutlet weak var dateLabel: UILabel!
    @IBOutlet weak var timeLabel: UILabel!

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

        updateTime()
        var timer = NSTimer()
        let aSelector : Selector = "updateTime"
        timer = NSTimer.scheduledTimerWithTimeInterval(0.01, target: self, selector: aSelector, userInfo: nil, repeats: true)

        var image : UIImage = UIImage(named:"afternoon")!
        bgImage = UIImageView(image: image)

    }

8 个解决方案

#1

Since you have your bgImage assigned and linked as an IBOutlet, there is no need to initialize it as a UIImageView... instead all you need to do is set the image property like bgImage.image = UIImage(named: "afternoon"). After running this code, the image appeared fine since it was already assigned using the outlet.

既然已经将bgImage分配并链接为IBOutlet，就不需要将它初始化为UIImageView…相反，您需要做的只是设置image属性，如bgImage。形象=用户界面图像(命名为:“下午”)。运行此代码后，图像看起来很好，因为它已经使用outlet分配了。

However, if it wasn't an outlet and you didn't have it already connected to a UIImageView object on a storyboard/xib file, then you could so something like the following...

但是，如果它不是一个outlet，而且你还没有将它连接到storyboard/xib文件上的UIImageView对象，那么你可以如下所示。

class ViewController: UIViewController {
    var bgImage: UIImageView?

    override func viewDidLoad() {
        super.viewDidLoad()

        var image: UIImage = UIImage(named: "afternoon")!
        bgImage = UIImageView(image: image)
        bgImage!.frame = CGRectMake(0,0,100,200)
        self.view.addSubview(bgImage!)
    }
}

#2

In xcode 8 you can directly choose image from the selection window (NEW)...

在xcode 8中，您可以直接从选择窗口(新建)中选择图像。

• You just need to type - "image" and you will get a suggestion box then select -"Image Literal" from list (see in attached picture) and

  你只需要键入“图像”，你就会得到一个建议框，然后从列表中选择“图像文字”(见附图)。

• then tap on the square you will be able to see all images(see in
  second attached picture) which are in your image assets... or select other image from there.

  然后点击方块，你就可以看到所有的图片(见附图)，它们都在你的图片资产中……或者从那里选择其他图像。

• Now tap on square box - (You will see that square box after selecting above option)
• 现在点击方框-(在选择以上选项后，你将看到方块方块)

#3

OK, got it working with this (creating the UIImageView programmatically):

好的，让它和这个一起工作(以编程方式创建UIImageView):

var imageViewObject :UIImageView

imageViewObject = UIImageView(frame:CGRectMake(0, 0, 600, 600))

imageViewObject.image = UIImage(named:"afternoon")

self.view.addSubview(imageViewObject)

self.view.sendSubviewToBack(imageViewObject)

#4

This code is in the wrong place:

这段代码在错误的地方:

var image : UIImage = UIImage(named:"afternoon")!
bgImage = UIImageView(image: image)
bgImage.frame = CGRect(x: 0, y: 0, width: 100, height: 200)
view.addSubview(bgImage)

You must place it inside a function. I recommend moving it inside the viewDidLoad function.

你必须把它放在一个函数里面。我建议在viewDidLoad函数中移动它。

In general, the only code you can add within the class that's not inside of a function are variable declarations like:

一般来说，在函数之外的类中可以添加的唯一代码是变量声明，比如:

@IBOutlet weak var bgImage: UIImageView!

#5

How about this;

这个怎么样;

myImageView.image=UIImage(named: "image_1")

where image_1 is within the assets folder as image_1.png.

其中image_1在assets文件夹中的位置为image_1.png。

This worked for me since i'm using a switch case to display an image slide.

这对我很有用，因为我使用一个开关盒来显示图像幻灯片。

#6

With swift syntax this worked for me :

使用快速语法，这对我很有效:

    let leftImageView = UIImageView()
    leftImageView.image = UIImage(named: "email")

    let leftView = UIView()
    leftView.addSubview(leftImageView)

    leftView.frame = CGRect(x: 0, y: 0, width: 40, height: 40)
    leftImageView.frame = CGRect(x: 10, y: 10, width: 20, height: 20)
    userNameTextField.leftViewMode = .always
    userNameTextField.leftView = leftView

#7

In Swift 4, if the image is returned as nil.

在Swift 4中，如果图像返回为nil。

Click on image, on the right hand side (Utilities) -> Check Target Membership

点击图像，在右边(实用工具)->检查目标成员

#8

If you want to do it the way you showed in your question, this is a way to do it inline

如果你想按照问题中显示的方式来做，这是一种内联的方式

class YourClass: UIViewController{

  @IBOutlet weak var tableView: UITableView!
  //other IBOutlets

  //THIS is how you declare a UIImageView inline
  let placeholderImage : UIImageView = {
        let placeholderImage = UIImageView(image: UIImage(named: "nophoto"))
        placeholderImage.contentMode = .scaleAspectFill
        return placeholderImage
    }()

   var someVariable: String!
   var someOtherVariable: Int!

   func someMethod(){
      //method code
   }

   //and so on
}