我有一个WPF桌面应用。
我有一个下拉框,其项目源设置为可观察的集合。
目的是显示用户列表。我在该表格上有一个按钮,可以删除所选用户。它将" Active"字段设置为" 0",其中" 1"未删除。
问题是,即使我可以看到可观察到的集合已减少1.但是从视觉上看,下拉列表显示了所有原始的用户状态。
这是我的XAML:
<ComboBox ItemsSource="{Binding Users}" DisplayMemberPath="Login"
SelectedValue="{Binding SelectedManagerUser}" />
这是它的VM位:
public ObservableCollection<UserRecord> Users
{
get
{
return (from users in UserRecord.Get().Where(d => d.Active == 1)
select new UserRecord
{
FName = users.FName,
SName = users.SName,
UserRecordId = users.UserRecordId,
Login = users.Login,
IsAdmin = users.IsAdmin,
UserRef = users.UserRef,
Disabled = users.Disabled,
Branch = users.Branch,
Department = users.Department,
Position = users.Position,
Salt = users.Salt,
}).OrderBy(d => d.Login).ToList();
}
set {
_Users = value; RaisePropertyChanged(InformedWorkerCommon.Constants.VM_Users); }
}
我的poco/型号:
public class UserRecord
{
public int UserRecordId { get; set; }
public string FName { get; set; }
public string SName { get; set; }
public string Login { get; set; }
public string Salt { get; set; }
public int IsAdmin { get; set; }
public string UserRef { get; set; }
public int Disabled { get; set; }
public string Branch { get; set; }
public string Position { get; set; }
public int Active { get; set; }
public string Department { get; set; }
public string ServerRef { get; set; }
public DateTime ServerTS { get; set; }
}
这是将活动字段设置为'0'的代码:
我的测试涉及与2个用户进行预加载
private void DeleteUser()
{
try
{
此时,用户计数为2
UserRecord.Save(new UserRecord()
{
UserRef=UserRef,
Branch = Branch,
Department = Department,
Disabled = Disabled == true ? 1 : 0,
FName = FName,
IsAdmin = 0,
Login = Login,
Position = Position,
SName = SName,
Active = 0,
});
此时,用户计数为1,但下拉列表仍然显示2个用户
DisplayInfoMessage(Properties.Resources.Deleted);
}
}
}
catch (Exception ex)
{
//handle the error
}
}
我对WPF是相对较新的,所以我可以在这里做一个正确的how叫?
您应该创建ObservableCollection的一个实例一个实例,然后从此实例中添加和删除项目。
您可以在视图模型的构造函数中创建集合,并将属性作为简单的自动插入式读取属性实现,例如:
public class ViewModel
{
public ViewModel()
{
Users = new ObservableCollection<UserRecord>((from users in UserRecord.Get().Where(d => d.Active == 1)
select new UserRecord
{
FName = users.FName,
SName = users.SName,
UserRecordId = users.UserRecordId,
Login = users.Login,
IsAdmin = users.IsAdmin,
UserRef = users.UserRef,
Disabled = users.Disabled,
Branch = users.Branch,
Department = users.Department,
Position = users.Position,
Salt = users.Salt,
}).OrderBy(d => d.Login).ToList());
}
public ObservableCollection<UserRecord> Users { get; }
}
然后,当您从源集合中添加或删除项目时,与用户属性绑定的ComboBox将被更新。但是,每当源属性的GETER被称为