Question

如果tableView为空，我将添加“无结果”标签。

extension UITableView {
    override open func layoutSubviews() {
        print("Table layoutSubviews")
        let label = UILabel(frame: self.bounds)
        if self.visibleCells.isEmpty {
            label.center = self.center
            label.text = "No Results"
            label.textAlignment = .center
            if label.superview == nil {
                self.addSubview(label)
            }
        } else {
            label.removeFromSuperview()
        }
    }
}

但这在更新/重新加载tableView（行更改）时不起作用。它在非空UITableView

上仍显示“无结果”

Answer 1

extension UITableView {

    func setMessage(_ message: String) {
        let lblMessage = UILabel(frame: CGRect(x: 0, y: 0, width: self.bounds.size.width, height: self.bounds.size.height))
        lblMessage.text = message
        lblMessage.textColor = .black
        lblMessage.numberOfLines = 0
        lblMessage.textAlignment = .center
        lblMessage.font = UIFont(name: "TrebuchetMS", size: 15)
        lblMessage.sizeToFit()

        self.backgroundView = lblMessage
        self.separatorStyle = .none
    }

    func clearBackground() {
        self.backgroundView = nil
        self.separatorStyle = .singleLine
    }
}

现在按如下所示使用此扩展名

func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {

    if items.count == 0 {
        tableView.setMessage("No results")
    } else {
        tableView.clearBackground()
    }

    return items.count
}

Answer 2

创建名称为“ TableViewHelper”的Swift类。您也可以在CollectionView中使用。

import UIKit

class TableViewHelper {

    class func EmptyMessage(message:String, tableview:UITableView,vc:UIViewController) {
    let rect = CGRect(origin: CGPoint(x: 0,y :0), size: CGSize(width: vc.view.bounds.size.width, height: vc.view.bounds.size.height))
    let messageLabel = UILabel(frame: rect)
    messageLabel.text = message
    messageLabel.textColor = UIColor.white
    messageLabel.numberOfLines = 0;
    messageLabel.textAlignment = .center
    messageLabel.font = UIFont(name: "TrebuchetMS", size: 15)
    messageLabel.sizeToFit()

    tableview.backgroundView = messageLabel;
    tableview.separatorStyle = .none;
    }
}

class ColelctionViewHelper {

    class func EmptyMessage(message:String, collectionview:UICollectionView,vc:UIViewController) {
    let rect = CGRect(origin: CGPoint(x: 0,y :0), size: CGSize(width: vc.view.bounds.size.width, height: vc.view.bounds.size.height))
    let messageLabel = UILabel(frame: rect)
    messageLabel.text = message
    messageLabel.textColor = UIColor.white
    messageLabel.numberOfLines = 0;
    messageLabel.textAlignment = .center
    messageLabel.font = UIFont(name: "TrebuchetMS", size: 15)
    messageLabel.sizeToFit()

    collectionview.backgroundView = messageLabel;
   // collectionview.separatorStyle = .none;
    }
}

这就是您的使用方式，

 func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int
{
  if YourArray.count>0{
            TableViewHelper.EmptyMessage(message: "", tableview: TableName,vc: self)
            return EventArray.count
        }else{
            TableViewHelper.EmptyMessage(message: "No Results", tableview: TableName,vc: self)
            return 0;
        }
}

空tableView上没有结果标签

2 个答案: