问题描述
所以我遇到了这个非常烦人的问题，我似乎无法让它更新我创建的任何数据库，更糟糕的是我可以看到实例显示更新的信息但没有应用它。我真的很陌生，这是我的第一个课程项目。 这是用于更新数据的代码： '''
using Project.Database;
using Project.DataClasses;
using Project.Pages.SuperPages;
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Xamarin.Essentials;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace Project.Pages.UpdateDeleteListItem
{
[XamlCompilation(XamlCompilationoptions.Compile)]
public partial class UpdateDeleteList : ContentPage
{
private new readonly Label Title;
private Style LabelStyle;
private StoreDetails UpdateStoreDetails;
private Entry SNum;
private Entry SName;
private Entry SMName;
private Entry Addy;
public UpdateDeleteList(string pageType,object Item)
{
InitializeComponent();
BindingContext = Item;
UpdateStoreDetails = (StoreDetails)Item;
SetLabelStyle();
string titleMsg = "Update or Delete Selected " + pageType;
Frame frame = new Frame();
Label title = new Label() {Text = titleMsg };
Title = title;
StackLayout titleStack = new StackLayout() { Children = { Title } };
frame.Content = titleStack;
if (pageType == "Store")
{
StoreUDLItem(frame);
}
if (pageType == "Ticket")
{
TicketUDLItem(frame);
}
StylePage();
}
private void SaveButton_Clicked(object sender,EventArgs args)
{
if (StoreCheckValues() == true)
{
var store = SName;
var storeManager = SMName;
var storeNumber = SNum;
var address = Addy;
var storeDataAccess = new StoreDataAccess();
UpdateStoreDetails.StoreName = store.Text;
UpdateStoreDetails.Storemanger = storeManager.Text;
UpdateStoreDetails.StoreNumber = storeNumber.Text;
UpdateStoreDetails.Address = address.Text;
//MerchandiserKey = GetMerchId()
storeDataAccess.SaveStoreDetails(UpdateStoreDetails);
storeDataAccess.SaveAllStoreDetails();
}
'''
这里是数据访问方法：
'''
using Project.DataClasses;
using sqlite;
using System;
using System.Collections.Generic;
using System.Collections.ObjectModel;
using System.IO;
using System.Text;
using Xamarin.Forms;
namespace Project.Database
{
class StoreDataAccess
{
private sqliteConnection database;
private static object collisionLock = new object();
public ObservableCollection<StoreDetails> StoreDetails { get; set; }
public StoreDataAccess()
{
database = DependencyService.Get<IDatabaseConnection>().DbConnectionStore();
database.CreateTable<StoreDetails>();
this.StoreDetails = new ObservableCollection<StoreDetails>(database.Table<StoreDetails>());
//AddNewTicket(new Ticket ticket);
}
//add ticket method
public void AddNewStore(StoreDetails item)
{
this.StoreDetails.Add(item);
}
//retrieve ticket method
public StoreDetails GetStoreDetails(int id)
{
lock (collisionLock)
{
return database.Table<StoreDetails>().FirstOrDefault(StoreDetails => StoreDetails.StoreId == id);
}
}
//save ticket
public int SaveStoreDetails(StoreDetails storeDetailsInstance)
{
lock (collisionLock)
{
if (storeDetailsInstance.StoreId != 0)
{
database.Update(storeDetailsInstance);
return storeDetailsInstance.StoreId;
}
else
{
database.Insert(storeDetailsInstance);
return storeDetailsInstance.StoreId;
}
//database.Commit();
}
}
public void SaveAllStoreDetails()
{
lock (collisionLock)
{
foreach (var storeDetailsInstance in this.StoreDetails)
{
if (storeDetailsInstance.StoreId != 0)
{
database.Update(storeDetailsInstance);
}
else
{
database.Insert(storeDetailsInstance);
}
}
}
}
'''
using Project.Database;
using Project.DataClasses;
using Project.Pages.UpdateDeleteListItem;
using sqlite;
using System;
using System.Collections.ObjectModel;
using System.ComponentModel;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using Xamarin.Forms;
using Xamarin.Forms.Xaml;
namespace Project.Pages.ListPages
{
[XamlCompilation(XamlCompilationoptions.Compile)]
public partial class StoreList : ContentPage
{
private ObservableCollection<StoreDetails> Items { get; set; }
private readonly StoreDataAccess storeDataAccess;
private readonly sqliteConnection database;
public StoreList()
{
InitializeComponent();
storeDataAccess = new StoreDataAccess();
this.BindingContext = this.storeDataAccess;
Items = storeDataAccess.StoreDetails;
StoreView.ItemsSource = Items;
}
async void Handle_ItemTapped(object sender,ItemTappedEventArgs e)
{
if (e.Item == null) { return; }
else
{
//var id = Items[e.ItemIndex].StoreId;
await Navigation.PushAsync(new UpdateDeleteList("Store",e.Item));
//deselect Item
((ListView)sender).SelectedItem = null;
}
}
//page reload handle
protected override void OnAppearing()
{
base.OnAppearing();
var dbname = "StoreListDatabase.db3";
var path = Path.Combine(System.Environment.GetFolderPath(Environment.SpecialFolder.Personal),dbname);
if (database == null)
{
new StoreDataAccess();
}
using (sqliteConnection conn = new sqliteConnection(path))
{
Items = storeDataAccess.StoreDetails;
StoreView.ItemsSource = Items;
}
}
}
}
'''
最后这是我的数据库模型：
'''
using System;
using System.Collections.Generic;
using System.Text;
using Xamarin.Forms;
using sqlite;
using System.ComponentModel;
namespace Project.DataClasses
{
class StoreDetails : INotifyPropertyChanged
{
private int _storeId;
[PrimaryKey,AutoIncrement,NotNull]
public int StoreId
{
get { return _storeId; }
set { _storeId = value; OnPropertyChanged(nameof(StoreId)); }
}
private string _storeName;
[NotNull,DefaultValue("Enter Store Name")]
public string StoreName
{
get { return _storeName; }
set { _storeName = value; OnPropertyChanged(nameof(_storeName)); }
}
private string _storemanger;
[NotNull,DefaultValue("Enter Store Managers Name")]
public string Storemanger
{
get { return _storemanger; }
set { _storemanger = value; OnPropertyChanged(nameof(Storemanger)); }
}
private string _storeNumber;
[NotNull,DefaultValue("Enter Store Number")]
public string StoreNumber
{
get { return _storeNumber; }
set { _storeNumber = value; OnPropertyChanged(nameof(StoreNumber)); }
}
private string _address;
[NotNull,DefaultValue("Enter Address")]
public string Address
{
get { return _address; }
set { _address = value; OnPropertyChanged(nameof(Address)); }
}
private int _merchandiserKey;
[NotNull]
public int MerchandiserKey
{
get { return _merchandiserKey; }
set { _merchandiserKey = value; OnPropertyChanged(nameof(MerchandiserKey)); }
}
public event PropertyChangedEventHandler PropertyChanged;
private void OnPropertyChanged(string propertyName)
{
this.PropertyChanged?.Invoke(this,new PropertyChangedEventArgs(propertyName));
}
}
}
'''
任何帮助将不胜感激
'''
public int SaveStoreDetails(StoreDetails storeDetailsInstance)
{
lock (collisionLock)
{
if (storeDetailsInstance.StoreId != 0)
{
database.Update(storeDetailsInstance);
return storeDetailsInstance.StoreId;
}
else
{
database.Insert(storeDetailsInstance);
return storeDetailsInstance.StoreId;
}
//database.Commit();
}
}
'''
这就是一切似乎都出错的地方，我只是不知道为什么
解决方法
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