又一個wpf問題。在wpf數據網格中綁定十進制值的問題
我有兩個DataGridTextColumn的小數值。出於某種原因,當我添加一個新行(列的初始值爲零)時,我必須在這兩列中的任意一欄中輸入兩次我的值。我第一次在其中鍵入一個值並將其輸出時,該值將返回到零。第二次輸入值後,
<DataGridTextColumn Header="Unit Price" EditingElementStyle="{StaticResource CellEditStyle}" Width="SizeToCells" MinWidth="90" Binding="{Binding ItemUnitPrice, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
<DataGridTextColumn Header="Qty" EditingElementStyle="{StaticResource CellEditStyle}" Width="SizeToCells" MinWidth="65" Binding="{Binding ItemQty, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged, ValidatesOnDataErrors=True}" />
dg綁定到我的虛擬機中的observablecollection。我不知道這有什麼關係呢,但我已經通過創建一個單獨的類(用於保存數據的用戶離開行時)增加了一個EndEdit中的事件對我OC:
public class ObservableProjectExpenseItems : ObservableCollection<ProjectExpenseItemsBO>
{
protected override void InsertItem(int index, ProjectExpenseItemsBO item)
{
base.InsertItem(index, item);
item.ItemEndEdit += new ProjectExpenseItemsBO.ItemEndEditEventHandler((x) =>
{
if (ItemEndEdit != null)
ItemEndEdit(x);
});
}
public event ProjectExpenseItemsBO.ItemEndEditEventHandler ItemEndEdit;
}
我的業務物體看起來是這樣的:
public class ProjectExpenseItemsBO : IDataErrorInfo, IEditableObject
{
public int RowID { get; set; }
public int ProjectExpenseID { get; set; }
public string ItemNumber { get; set; }
public string ItemDescription { get; set; }
public decimal ItemUnitPrice { get; set; }
public decimal ItemQty { get; set; }
public string SupplierName { get; set; }
public DateTime CreateDate { get; set; }
public ProjectExpenseItemsBO()
{
}
// string method
static bool IsStringMissing(string value)
{
return String.IsNullOrEmpty(value) || value.Trim() == String.Empty;
}
private bool _isValid = true;
public bool IsValid
{
get { return _isValid; }
set { _isValid = value; }
}
#region IDataErrorInfo Members
public string Error
{
get
{
return this[string.Empty];
}
}
public string this[string propertyName]
{
get
{
string result = string.Empty;
if (propertyName == "ProjectExpenseID")
{
if (this.ProjectExpenseID == 0)
result = "An existing project expense item must be selected!";
}
if (propertyName == "ItemNumber")
{
if (this.ItemNumber != null)
{
if (IsStringMissing(this.ItemNumber))
result = "Item number cannot be empty!";
if (this.ItemNumber.Length > 50)
result = "Item number cannot be longer than 50 characters!";
}
}
if (propertyName == "ItemDescription")
{
if (this.ItemDescription != null)
{
if (this.ItemDescription.Length > 256)
result = "Item description cannot be longer than 256 characters!";
}
}
if (propertyName == "ItemUnitPrice")
{
if (this.ItemUnitPrice == 0.0M)
result = "Item unit price cannot be empty!";
}
if (propertyName == "ItemQty")
{
if (this.ItemQty == 0.0M)
result = "Item quantity cannot be empty!";
}
if (propertyName == "SupplierName")
{
if (this.SupplierName != null)
{
if (this.SupplierName.Length > 128)
result = "Item number cannot be longer than 128 characters!";
}
}
if (result.Length > 0)
IsValid = false;
else
IsValid = true;
return result;
}
}
#endregion
#region IEditableObject Members
public delegate void ItemEndEditEventHandler(IEditableObject sender);
public event ItemEndEditEventHandler ItemEndEdit;
public void BeginEdit()
{
//throw new NotImplementedException();
}
public void CancelEdit()
{
//throw new NotImplementedException();
}
public void EndEdit()
{
if (ItemEndEdit != null)
{
ItemEndEdit(this);
}
}
#endregion
}
}