swift - UIPicker 选择显示为白色

Question

我在实现 UIPicker 时遇到了一些问题。当我查看它时，有些行显示为白色/透明。稍微滚动并返回后，该行终于出现了。

截图如下:

第一行保持白色

在第二行上滚动也是如此

行在完全滚动并返回后最终出现

这是代码

// reinitializing array to nil
pickerContentArray = []

for i in 0..<specialitiesList.count {
    pickerContentArray.append(specialitiesList[i]["name"] as! String)
}

picker.reloadAllComponents()
picker.selectRow(0, inComponent: 0, animated: false)

---

    //MARK: - Delegates and data sources
//MARK: Data Sources
func numberOfComponentsInPickerView(pickerView: UIPickerView) -> Int {
    return 1
}
func pickerView(pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return pickerContentArray.count
}

func pickerView(pickerView: UIPickerView, viewForRow row: Int, forComponent component: Int, reusingView view: UIView!) -> UIView
{
    var pickerLabel = UILabel()
    pickerLabel.textColor = UIColor.blackColor()

    if pushedButton == "Speciality" {
        pickerLabel.text = specialitiesList[row]["name"] as? String
        pickerLabel.font = UIFont(name: "Helvetica", size: 12)
    } else if pushedButton == "Status" {
        pickerLabel.text = statusList[row]
        pickerLabel.font = UIFont(name: "Helvetica", size: 16)
    } else if pushedButton == "City" {
        pickerLabel.text = citiesList[row]["name"] as? String
        pickerLabel.font = UIFont(name: "Helvetica", size: 16)
    }

    pickerLabel.textAlignment = NSTextAlignment.Center
    return pickerLabel
}

//MARK: Delegates
func pickerView(pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String! {
    return pickerContentArray[row]
}

谢谢，

Answer 1

也许您过早地调用了设置代码。

尝试在 viewWillAppear() 而不是 viewDidLoad() 中完成。

也有可能是因为你选择了没有动画的组件，导致组件没有正常更新。在显示 View 之前，您应该为动画传递 false，但如果选择器已经对用户可见，则传递 true。