DevExpress GridControl Does not Update properly even I set up the NotifyPropertyChanged event correctly - devexpress

Question

I met a very strange Problem.
The basic idea is that I have a class to save data received from a trading api about forex price. Each property has been set with NotifyPropertyChanged method like below.
class RealTimeBar
{
public event PropertyChangedEventHandler PropertyChanged;
private const double EPSILON = 0.0000001;
private int _id;
private string _symbol;
private int _time;
private float _open;
private float _high;
private float _low;
private float _close;
int _volume;
public RealTimeBar(int id, string symbol)
{
_id = id;
_symbol = symbol;
}
private void NotifyPropertyChanged(String info)
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(info));
}
}
public int Id
{
get
{
return _id;
}
set
{
_id = value;
}
}
public string Symbol
{
get
{
return _symbol;
}
set
{
if (value != _symbol)
{
_symbol = value;
NotifyPropertyChanged("Symbol");
}
}
}
public int Time
{
get
{
return _time;
}
set
{
if (value != _time)
{
_time = value;
NotifyPropertyChanged("Time");
}
}
}
public float Open
{
get
{
return _open;
}
set
{
if (value != _open)
{
_open = value;
NotifyPropertyChanged("Open");
}
}
}
public float High
{
get
{
return _high;
}
set
{
if (value != _high)
{
_high = value;
NotifyPropertyChanged("High");
}
}
}
public float Low
{
get
{
return _low;
}
set
{
if (value != _low)
{
_low = value;
NotifyPropertyChanged("Low");
}
}
}
public float Close
{
get
{
return _close;
}
set
{
if (value != _close)
{
_close = value;
NotifyPropertyChanged("Close");
}
}
}
public int Volume
{
get
{
return _volume;
}
set
{
if (value != _volume)
{
_volume = value;
NotifyPropertyChanged("Volume");
}
}
}
}
It is quote a long class but with simple structure as you can see. Now I connected to api which fire event to me and I handle it by set the value from api to the class i defined.
BindingList<RealTimeBar> _realTimeBarList = new BindingList<RealTimeBar>();
public Hashtable _iForexHashtable = new Hashtable();
private void _UpdateForexQuote(int tickerId, int time, double open, double high, double low, double close, int volume,
double wap, int count)
{
///MessageBox.Show(tickerId.ToString());
((RealTimeBar)_iForexHashtable[tickerId]).Open = (float)open;
((RealTimeBar)_iForexHashtable[tickerId]).High = (float)high;
((RealTimeBar)_iForexHashtable[tickerId]).Low = (float)low;
((RealTimeBar)_iForexHashtable[tickerId]).Close = (float)close;
((RealTimeBar)_iForexHashtable[tickerId]).Volume = volume;
}
After some setting up, the method _UpdateForexQuote would distribute the coming info into properties of RealTimeBar class. Everything is fine.
When I start the program, it does not update. I thought that there is no data coming in. But when I randomly click somewhere in the A1cell of gridcontrol, then click another B1cell, the previous A1cell would update. Then if i click C1cell, then the B1cell would update. If you do not click one cell , it would never update. I show you the picture:
As you can see, that after clicking first three lines, the first three lines showed delayed data and since I never touch the fourth line, it shows zero. And the condition is that I just clicked the fifth line Low cell, that is why the Low does not update but other cells updated. It is very strange. I use same code before under devexpress 11 with vs 2010. But now with devexpress 12 with vs 2012, I met this problem which never occurred before.
UPDATE:
Below is the method I use to 1. define bindinglist and a hashtable, 2. put objects into the hashtable first and add the object from hashtable to bindinglist 3. bind the bindinglist to gridcontrol.
private void earningButtonItem_ItemClick(object sender, ItemClickEventArgs e)
{
_iTimer.AutoReset = false;
_iTimer.Enabled = false;
switchStockPool = "Earning Stock";
disconnectButtonItem.PerformClick();
connectButtonItem.PerformClick();
_iheitanshaoEarningDBConnect = new DBConnect("heitanshaoearning");
List<string>[] tempList;
int tempHash;
tempList = _iheitanshaoEarningDBConnect.SelectSymbolHighLow();
_quoteEarningOnGridList.Clear();
///tempList[0].Count
for (int i = 0; i < tempList[0].Count; i++)
{
tempHash = Convert.ToInt32(tempList[0][i].ToString().GetHashCode());
_iStockEarningHistHashtable[tempHash] = new QuoteOnGridHist(tempList[0][i], (float)Convert.ToSingle(tempList[1][i]), (float)Convert.ToSingle(tempList[2][i]), (float)Convert.ToSingle(tempList[3][i]));
_iStockEarningHashtable[tempHash] = new QuoteOnGrid(tempList[0][i], 0, 0);
_quoteEarningOnGridList.Add((QuoteOnGrid)_iStockEarningHashtable[tempHash]);
reqMktDataExStock(tempHash, tempList[0][i].ToString());
}
List<string>[] tempVolumeList;
tempVolumeList = _iheitanshaoEarningDBConnect.SelectAverageVolume();
for (int i = 0; i < tempList[0].Count; i++)
{
tempHash = Convert.ToInt32(tempVolumeList[0][i].ToString().GetHashCode());
((QuoteOnGrid)_iStockEarningHashtable[tempHash]).Average_Volume = ((float)Convert.ToSingle(tempVolumeList[1][i])) / volumeDenominator;
}
gridControl.DataSource = _quoteEarningOnGridList;
}
/////////////////////
Now when the price update event comes, the method below will update the object properties in hashtable. Since I defined Notifypropertychanged in object, it should update the object in bingdinglist and gridcontrol.
private void _UpdateStockMarketQuote(int tikcerId, int field, double price, int canAutoExecute)
{
////MessageBox.Show(tikcerId.ToString() + field.ToString() + price.ToString());
if (switchStockPool == "Selected Stock")
{
if (field == 4)
{
((QuoteOnGrid)_iStockHashtable[tikcerId]).Gap_From_High = ((float)price - ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).High) / ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Close;
((QuoteOnGrid)_iStockHashtable[tikcerId]).Gap_From_Low = ((float)price - ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Low) / ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Close;
((QuoteOnGrid)_iStockHashtable[tikcerId]).Last_Price = (float)price;
}
//else if (field == 1)
//{
// ((QuoteOnGrid)_iStockHashtable[tikcerId]).Gap_From_High = ((float)price - ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).High) / ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Close;
// ((QuoteOnGrid)_iStockHashtable[tikcerId]).Gap_From_Low = ((float)price - ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Low) / ((QuoteOnGridHist)_iStockHistHashtable[tikcerId]).Close;
//}
}
else if (switchStockPool == "Earning Stock")
{
if (field == 4)
{
((QuoteOnGrid)_iStockEarningHashtable[tikcerId]).Gap_From_High = ((float)price - ((QuoteOnGridHist)_iStockEarningHistHashtable[tikcerId]).High) / ((QuoteOnGridHist)_iStockEarningHistHashtable[tikcerId]).Close;
((QuoteOnGrid)_iStockEarningHashtable[tikcerId]).Gap_From_Low = ((float)price - ((QuoteOnGridHist)_iStockEarningHistHashtable[tikcerId]).Low) / ((QuoteOnGridHist)_iStockEarningHistHashtable[tikcerId]).Close;
((QuoteOnGrid)_iStockEarningHashtable[tikcerId]).Last_Price = (float)price;
}
//else if (field == 1)
//{
// ((quoteongrid)_istockearninghashtable[tikcerid]).gap_from_high = ((float)price - ((quoteongridhist)_istockearninghisthashtable[tikcerid]).high) / ((quoteongridhist)_istockearninghisthashtable[tikcerid]).close;
// ((quoteongrid)_istockearninghashtable[tikcerid]).gap_from_low = ((float)price - ((quoteongridhist)_istockearninghisthashtable[tikcerid]).low) / ((quoteongridhist)_istockearninghisthashtable[tikcerid]).close;
//}
}
}

Answer 1

Not only you need to have PropertyChanged event in a class, you need to implement INotifyPropertyChanged. That's how the grid knows a class can inform of changes.