在Swift的UI PickerView组件显示图像
问题说明
我正在尝试在Swift PickerView中使用图像。我不知道如何让图像实际出现在组件中。我知道如何使用带有titleForRow函数的字符串来执行此操作，但我不知道如何使用图像执行此操作。这是我到目前为止的代码：
I am trying to use images in a Swift PickerView. I don't know how to get the images to actually appear in the component. I know how to do this using Strings with the titleForRow function but I don't know how to do this using images. Here is my code so far:
import UIKit
class ViewController: UIViewController, UIPickerViewDelegate {
@IBOutlet weak var pickerView: UIPickerView!
var imageArray: [UIImage] = [UIImage(named: "washington.jpg")!,
UIImage(named: "berlin.jpg")!, UIImage(named: "beijing.jpg")!,
UIImage(named: "tokyo.jpg")!]
override func viewDidLoad() {
super.viewDidLoad()
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
// returns the number of 'columns' to display.
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int{
return 1
}
// returns the # of rows in each component..
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return imageArray.count
}
}// end of app
正确答案
您需要为UIPickerViewDelegate协议实现更多的委托方法。特别是一个rowHeight委托方法和一个viewForRow委托方法。
You will need to implement a couple more the delegate methods for the UIPickerViewDelegate protocol. In particular a rowHeight delegate method and a viewForRow delegate method.
类似于：
// MARK: UIPickerViewDataSource
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
return 2
}
func pickerView(pickerView: UIPickerView, rowHeightForComponent component: Int) -> CGFloat {
return 60
}
// MARK: UIPickerViewDelegate
func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView {
var myView = UIView(frame: CGRectMake(0, 0, pickerView.bounds.width - 30, 60))
var myImageView = UIImageView(frame: CGRectMake(0, 0, 50, 50))
var rowString = String()
switch row {
case 0:
rowString = "Washington"
myImageView.image = UIImage(named:"washington.jpg")
case 1:
rowString = "Beijing"
myImageView.image = UIImage(named:"beijing.jpg")
case 2:
default:
rowString = "Error: too many rows"
myImageView.image = nil
}
let myLabel = UILabel(frame: CGRectMake(60, 0, pickerView.bounds.width - 90, 60 ))
myLabel.font = UIFont(name:some font, size: 18)
myLabel.text = rowString
myView.addSubview(myLabel)
myView.addSubview(myImageView)
return myView
}
func pickerView(pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {
// do something with selected row
}
请注意，标签布局等仅用于演示，需要调整，或者更好地使用自动布局等。
Note that the label layout etc is just for demonstration, would need to be tweaked, or probably better to use Auto Layout ect.
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