我想通过其Id删除该行，但我不能通过其Id.like删除它，例如值 date | time | Floor | zone | Latitude |经度，我想在选择它时删除它的一行，但我不能。我是写下所有主要功能的类
public class DbHelper
{
SQLiteConnection dbConn;
public async Task<bool> onCreate(string DB_PATH)
{
try
{
if (!CheckFileExists(DB_PATH).Result)
{
using (dbConn = new SQLiteConnection(DB_PATH))
{
dbConn.CreateTable<historyTableSQlite>();
}
}
return true;
}
catch
{
return false;
}
}
private async Task<bool> CheckFileExists(string fileName)
{
try
{
var store = await Windows.Storage.ApplicationData.Current.LocalFolder.GetFileAsync(fileName);
return true;
}
catch
{
return false;
}
}
//retrieve all list from the database
public ObservableCollection<historyTableSQlite> ReadHistory()
{
using (var dbConn = new SQLiteConnection(App.DB_PATH))
{
List<historyTableSQlite> myCollection = dbConn.Table<historyTableSQlite>().ToList<historyTableSQlite>();
ObservableCollection<historyTableSQlite> HistoryList = new ObservableCollection<historyTableSQlite>(myCollection);
return HistoryList;
}
}
// Insert the new info in the histrorytablesqlite table.
public void Insert(historyTableSQlite newcontact)
{
using (var dbConn = new SQLiteConnection(App.DB_PATH))
{
dbConn.RunInTransaction(() =>
{
dbConn.Insert(newcontact);
});
}
}
public void AddInfo()
{
//string f = Checkin.Floor_st;
Debug.WriteLine(Checkin.a);
string z = Checkin.Zone_st;
DbHelper Db_helper = new DbHelper();
Db_helper.Insert((new historyTableSQlite
{
Date = DateTime.Now.ToShortDateString(),
Time = DateTime.Now.ToShortTimeString(),
Zone = "D",
Floor = "7",
latitude =12344.66,
longtitude = -122.56
}));
}
// Delete specific contact
public void DeleteContact(int Id)
{
using (var dbConn = new SQLiteConnection(App.DB_PATH))
{
var existingvalue = dbConn.Query<historyTableSQlite>("select * from historyTableSQlite where Id =" + Id).FirstOrDefault();
if (existingvalue != null)
{
dbConn.RunInTransaction(() =>
{
dbConn.Delete(existingvalue);
});
}
}
}
//Delete all contactlist or delete Contacts table
public void DeleteAllContact()
{
using (var dbConn = new SQLiteConnection(App.DB_PATH))
{
//dbConn.RunInTransaction(() =>
// {
dbConn.DropTable<historyTableSQlite>();
dbConn.CreateTable<historyTableSQlite>();
dbConn.Dispose();
dbConn.Close();
//});
}
}
}
是我显示值
的类public partial class History : PhoneApplicationPage
{
ObservableCollection<historyTableSQlite> DB_HistoryList = new ObservableCollection<historyTableSQlite>();
DbHelper Db_helper = new DbHelper();
//int Selected_HistoryId;
public static int Selected_HistoryId { get; set; }
// string dbPath = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "db.sqlite");
public History()
{
InitializeComponent();
}
protected override void OnNavigatedTo(NavigationEventArgs e)
{
Db_helper.AddInfo();
ReadHistoryList_Loaded();
// Selected_HistoryId = int.Parse(NavigationContext.QueryString["SelectedHistoryID"]);
}
public void ReadHistoryList_Loaded()
{
ReadAllContactsList dbhistory = new ReadAllContactsList();
DB_HistoryList = dbhistory.GetAllHistory();//Get all DB contacts
ListData.ItemsSource = DB_HistoryList.OrderByDescending(i => i.Id).ToList();
//Latest contact ID can Display first
}
public void ListData_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (ListData.SelectedIndex != -1)
{
historyTableSQlite listitem = ListData.SelectedItem as historyTableSQlite;
int Selected_HistoryId = listitem.Id;
}
}
public void Delete_Click(object sender, EventArgs e)
{
Db_helper.DeleteContact(Selected_HistoryId);
}
private void DeleteAll_Click(object sender, EventArgs e)
{
DbHelper Db_helper = new DbHelper();
Db_helper.DeleteAllContact();//delete all db
DB_HistoryList.Clear();
ListData.ItemsSource = DB_HistoryList;
}
//public void updateDB(string fl,string zo,double la, double lo)
//{
// using (var db = new SQLiteConnection(dbPath))
// {
// var existing = db.Query<historyTableSQlite>("select * from historyTableSQlite").FirstOrDefault();
// if (existing != null)
// {
// existing.Floor = fl;
// existing.Zone = zo;
// existing.latitude = la;
// existing.longtitude = lo;
// db.RunInTransaction(() =>
// {
// db.Update(existing);
// });
// }
// }
//}
//public void AddDb(string fl, string zo, double la, double lo)
//{
// string dbPath = Path.Combine(Windows.Storage.ApplicationData.Current.LocalFolder.Path, "db.sqlite");
// using (var db = new SQLiteConnection(dbPath))
// {
// db.RunInTransaction(() =>
// {
// db.Insert(new historyTableSQlite()
// {
// Date = DateTime.Today.ToShortDateString(),
// Time = DateTime.Now.ToShortTimeString(),
// Floor = fl,
// Zone = zo,
// longtitude = la,
// latitude = lo
// });
// Debug.WriteLine(db);
// });
// }
}
我正在更新表类，以便于理解
public class historyTableSQlite : INotifyPropertyChanged
{ [SQLite.PrimaryKey，SQLite.AutoIncrement]
public int Id { get; set; }
private int idvalue;
private string dateValue = string.Empty;
public string Date {
get { return this.dateValue; }
set
{
if (value != this.dateValue)
{
this.dateValue = value;
NotifyPropertyChanged("Date");
}
}
}
private string timeValue = string.Empty;
public string Time
{
get { return this.timeValue; }
set
{
if (value != this.timeValue)
{
this.timeValue = value;
NotifyPropertyChanged("Time");
}
}
}
private string floorValue = string.Empty;
public string Floor
{
get { return this.floorValue; }
set
{
if (value != this.floorValue)
{
this.floorValue = value;
NotifyPropertyChanged("Floor");
}
}
}
public string zoneValue;
public string Zone
{
get { return this.zoneValue; }
set
{
if (value != this.zoneValue)
{
this.zoneValue = value;
NotifyPropertyChanged("Zone");
}
}
}
private double latValue;
public double latitude
{
get { return latValue; }
set
{
if (value != this.latValue)
{
this.latValue = value;
NotifyPropertyChanged("Latitude");
}
}
}
private double lonValue;
public double longtitude
{
get { return this.lonValue; }
set
{
if (value != this.lonValue)
{
this.lonValue = value;
NotifyPropertyChanged("Longitude");
}
}
}
// public string isMarkPoint {get;组; }
public historyTableSQlite()
{
}
public historyTableSQlite(string date,string time,string floor,string zone,double lat,double lng)
{
Date = date;
Time = time;
Floor = floor;
Zone = zone;
latitude = lat;
longtitude = lng;
}
public event PropertyChangedEventHandler PropertyChanged;
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
}
当我点击删除，即方法delete_click我不能删除行
答案 0 :(得分：0)
编辑：我错误地剪切并粘贴了你的代码......你的对齐很差：）
好吧，我想我终于让你的代码运行了，你的问题就在这里
public void ListData_SelectionChanged(object sender, SelectionChangedEventArgs e)
{
if (ListData.SelectedIndex != -1)
{
historyTableSQlite listitem = ListData.SelectedItem as historyTableSQlite;
// this will get destroy when the function exits, it's local decalartion
int Selected_HistoryId = listitem.Id;
// History.Selected_HistoryId = listitem.Id;
// you need to set the Property not a local variable
}
}
你创建了一个名为与它应该属性相同的局部变量
History.Selected_HistoryId = listitem.Id;
public void Delete_Click(object sender, EventArgs e)
{
Db_helper.DeleteContact(History.Selected_HistoryId);
}