Question

有人可以帮助我在email单元格中显示tableView字段吗？ amount字段正在显示，但我无法同时显示email。

struct Posts {
    var amount:String
    var email:String
}

class PaymentRequestVC: UIViewController, UITableViewDelegate {
    
    let tableView = UITableView()
   
    var posts = [Posts]()

    override func viewDidLoad() {
        super.viewDidLoad()
        view.backgroundColor = .white
        self.tableView.dataSource = self
        self.tableView.delegate = self
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell")
        tableView.register(UITableViewCell.self, forCellReuseIdentifier: "cell2")
        tableView.frame = CGRect(x: 0, y: 0, width: self.view.frame.width, height: 900)
        setupViews()
        setupTableView()
        loadPosts()
        self.tableView.reloadData()
        
    
    }

    func loadPosts() {
        let dbUsers = Firestore.firestore().collection("Payouts")
        dbUsers.addSnapshotListener { (querySnapshot, error) in
            if let error = error {
                print("\(error.localizedDescription)")
            } else {
                for document in (querySnapshot?.documents)! {
                    if let Amount = document.data()["amount"] as? String {
                        let Email = document.data()["email"] as? String
                        print(Amount)
                        var post = Posts(amount: "", email: "")
                        post.amount = Amount
                        post.email = Email ?? ""

                        self.posts.append(post)
                    }
                }
                
                    self.tableView.reloadData()
                
                print(self.posts)
            }
        }
      }
    
    private func setupViews() {
    let stackView: UIStackView = {
        let sv = UIStackView()
        sv.translatesAutoresizingMaskIntoConstraints = false
        sv.spacing = 28
        sv.axis = .vertical
        sv.distribution = .fill
        sv.alignment = .fill
        return sv
        }()
        view.addSubview(stackView)
        view.addSubview(tableView)

    }
    
    func setupTableView() {
           
           NSLayoutConstraint.activate([
                  tableView.topAnchor.constraint(equalTo: self.view.topAnchor),
                  tableView.bottomAnchor.constraint(equalTo: self.view.bottomAnchor),
                  tableView.rightAnchor.constraint(equalTo: self.view.rightAnchor),
                  tableView.leftAnchor.constraint(equalTo: self.view.leftAnchor)
              ])
           }
}

extension PaymentRequestVC: UITableViewDataSource {
    func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
        return posts.count
}

    func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if indexPath.row < posts.count {
                let cell = tableView.dequeueReusableCell(withIdentifier: "cell", for: indexPath)
                let post = posts[indexPath.row]
                cell.textLabel?.text = post.amount
                cell.textLabel?.textColor = UIColor.black
                return cell
            } else {
                let cell2 = tableView.dequeueReusableCell(withIdentifier: "cell2", for: indexPath)
                let post = posts[indexPath.row]
                cell2.detailTextLabel?.text = post.email
                cell2.detailTextLabel?.textColor = UIColor.black
                return cell2
            }
 }
    
    func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
        return 80
    }
}

Answer 1

快捷键5

您需要使用 UITableViewCell.CellStyle.subtitle 初始化单元格，以使 detailTextLabel 属性起作用。

在扩展程序中，更改 cell 初始化：

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if indexPath.row < posts.count {
            let cell = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell")
            let post = posts[indexPath.row]
            cell.textLabel?.text = post.amount
            cell.textLabel?.textColor = UIColor.black
            cell.detailTextLabel?.text = post.email
            cell.detailTextLabel?.textColor = UIColor.black
            return cell
        } else {
            let cell2 = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell2")
            let post = posts[indexPath.row]
            cell2.detailTextLabel?.text = post.email
            cell2.detailTextLabel?.textColor = UIColor.black
            return cell2
        }

请注意，如果要同时显示 amount 和 mail ，则使用 else 将只显示金额或电子邮件，就像下面的代码一样

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if indexPath.row < posts.count {
            let cell = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell")
            let post = posts[indexPath.row]
            cell.textLabel?.text = post.amount
            cell.textLabel?.textColor = UIColor.black
            return cell
        } else {
            let cell2 = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell2")
            let post = posts[indexPath.row]
            cell2.detailTextLabel?.text = post.email
            cell2.detailTextLabel?.textColor = UIColor.black
            return cell2
        }

所以更好的方法是同时返回两者，而 else 不显示任何内容

func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
        if indexPath.row < posts.count {
            let cell = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell")
            let post = posts[indexPath.row]
            cell.textLabel?.text = post.amount
            cell.textLabel?.textColor = UIColor.black
            cell.detailTextLabel?.text = post.email
            cell.detailTextLabel?.textColor = UIColor.black
            return cell
        } else {
            let cell2 = UITableViewCell(style: UITableViewCell.CellStyle.subtitle, reuseIdentifier: "cell2")
            //Empty cell returned if the condition above is not fulfilled
            return cell2
        }

希望这会有所帮助。

Answer 2

我认为您在cellForRowAt中的逻辑不正确。

您有一系列的帖子。您想在同一单元格中显示金额和电子邮件吗？一个标签是标题，另一个标签是详细文本。

两个标签都位于同一UITableViewCell中，因此每个帖子只需要设置一次即可。

此外，如果indexPath.row大于帖子数，则posts [indexPath.row]实际上会使您的代码崩溃。因此，else语句实际上应该只是记录错误或什么都不做。

尝试这样的事情：

import numpy as np
import pandas as pd
import timeit
from numba import jit

np.random.seed(1)
df = pd.DataFrame(np.random.randint(0,100,size=(1000000, 1)), columns=['TR'])


def sma(df):
    # code copied from the question 

    samples = len(df)
    # MAverage
    tr = df['TR']

    df['trsum'] = float(0)
    trsum = df['trsum']

    df['Avg Range'] = float(0)
    ma = df['Avg Range']

    trsum[1] = tr[1]
    for ii in range(2, samples):
        trsum[ii] = trsum[ii - 1] + tr[ii]
        if ii > 19:
            ma[ii] = trsum[ii] / 20
            trsum[ii] = trsum[ii] * 19 / 20

    return df


def sma_numpy(df):
    tr = 0
    trsum = 1
    ma = 2

    samples = len(df)

    df['trsum'] = float(0)
    df['Avg Range'] = float(0)
    npa = df.to_numpy()

    npa[1,1] = npa[1,0]

    for ii in range(2, samples):
        npa[ii,trsum] = npa[ii-1,trsum] + npa[ii,tr]
        if ii > 19:
            npa[ii,ma] = npa[ii,trsum] / 20
            npa[ii, trsum] *= 19 / 20


    return pd.DataFrame(data=npa, columns=df.columns)


@jit(nopython=True)
def sma_numba_loop(npa):
    tr = 0
    trsum = 1
    ma = 2
    samples = len(npa)

    for ii in range(2, samples):
        npa[ii, trsum] = npa[ii - 1, trsum] + npa[ii, tr]
        if ii > 19:
            npa[ii, ma] = npa[ii, trsum] / 20
            npa[ii, trsum] *= 19 / 20


def sma_numba(df):

    df['trsum'] = float(0)
    df['Avg Range'] = float(0)
    npa = df.to_numpy()

    npa[1, 1] = npa[1, 0]

    sma_numba_loop(npa)

    return pd.DataFrame(data=npa, columns=df.columns)


df_small = df[0:100_000].copy()
print(sma_numba(df[0:30].copy())) # JIT compile to save time

print("def sma() Pandas: ", timeit.Timer(lambda: sma(df_small.copy())).timeit(number=1), f's for {len(df_small)} rows', sep='')
print("def sma_numpy() Numpy: ", timeit.Timer(lambda: sma_numpy(df.copy())).timeit(number=1), f's for {len(df)} rows', sep='')
print("def sma_numba() Numpy + Numba: ", timeit.Timer(lambda: sma_numba(df.copy())).timeit(number=1), f's for {len(df)} rows', sep='')

'''
Check a sample to make sure they all return the same values
print(sma(df_small.copy())[10000:10010])
print(sma_numpy(df.copy())[10000:10010])
print(sma_numba(df.copy())[10000:10010])
'''

如何将多个项目添加到UITableViewCell？

2 个答案: