我是wpf和mvvm的新手，我试着先学会使用它，我成功地显示了我的员工类列表，非常好，但当我想添加一个新的(意味着新员工(时，它会在数据库中保存一条新的空记录，我不知道如何从文本框中获取值。我搜索了很多，但无法找到我的问题所在，所以我能在这里得到任何帮助吗？这是我的代码
MY MODEL CLASS
public class Employees
{
#region Employee Members
int _id;
string _firstname;
string _address;
string _lastname;
string _language;
string _dob;
string _nationality;
string _gender;
#endregion
#region Members Properties
Notify.NotifyUIBase n = new Notify.NotifyUIBase();
public int ID
{
get { return _id; }
set
{
_id = value;
}
}
public string FirstName
{
get { return this._firstname; }
set
{
if (value != this._firstname)
{
this._firstname = value;
n.RaisePropertyChanged("FirstName");
}
}
}
public string Address
{
get { return _address; }
set
{
_address = value;
n.RaisePropertyChanged("Address");
}
}
public string LastName
{
get { return _lastname; }
set
{
_lastname = value;
n.RaisePropertyChanged("LastName");
}
}
public string Language
{
get { return _language; }
set
{
_language = value;
n.RaisePropertyChanged("Language");
}
}
public string DOB
{
get { return _dob; }
set
{
_dob = (value).ToString();
n.RaisePropertyChanged("DOB");
}
}
public string Nationality
{
get { return _nationality; }
set
{
_nationality = value;
n.RaisePropertyChanged("Nationality");
}
}
public string Gender
{
get { return _gender; }
set
{
_gender = value;
n.RaisePropertyChanged("Gender");
}
}
#endregion
}
MY NOTIFY CLASS
public class NotifyUIBase : INotifyPropertyChanged
{
public event PropertyChangedEventHandler PropertyChanged;
public void RaisePropertyChanged([CallerMemberName] String propertyName = "")
{
if (PropertyChanged != null)
{
PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
}
}
}
MY VIEWMODEL
public class EditaEmployeesViewModel
{
#region Constructor
public EditaEmployeesViewModel()
{
// intiales commands
NewEmployeeButton = new RelayCommand(OpenNewEmployee);
UpdateEmployeeButton = new RelayCommand(UpdateEmployee);
DeleteEmployeeButton = new RelayCommand(DeleteEmployee);
SaveNewEmployeeButton = new RelayCommand(SaveNewEmployee);
}
#endregion
#region Variables
public RelayCommand NewEmployeeButton { get; set; }
public RelayCommand UpdateEmployeeButton { get; set; }
public RelayCommand DeleteEmployeeButton { get; set; }
public RelayCommand SaveNewEmployeeButton { get; set; }
#endregion
#region Command Methods
void OpenNewEmployee(object parameter)
{
View.AddUpdateEmployee aue = new View.AddUpdateEmployee();
aue.Show();
}
void UpdateEmployee(object parameter)
{
}
void DeleteEmployee(object parameter)
{
}
void SaveNewEmployee(object parameter)
{
DataAccess.EmplyeeDatabaseLayer.InsertEmployee(** what to pass here
to the insert sql ***);
}
#endregion
#region get Employee List
public ObservableCollection<Model.Employees> EmployeeList
{
get
{
ObservableCollection<Model.Employees> List = new ObservableCollection<Model.Employees>(DataAccess.EmplyeeDatabaseLayer.GetEmployeeFromDataBase());
return List;
}
}
#endregion
MY DATABASE CLASS
public class EmplyeeDatabaseLayer
{
public static List<Model.Employees> GetEmployeeFromDataBase()
{
string sql = "select * from Employees";
DataTable dt = DBConnections.SelectQuery(sql);
var Employee = new List<Model.Employees>();
foreach (DataRow row in dt.Rows)
{
var obj = new Model.Employees()
{
ID = (int)row["id"],
FirstName = (string)row["FirstName"],
LastName = (string)row["LastName"],
DOB = (string)row["DOB"],
Gender = (string)row["Gender"],
Nationality = (string)row["Nationality"],
Language = ((string)row["Language"]),
Address = (string)row["Address"]
};
Employee.Add(obj);
}
return Employee;
}
internal static void InsertEmployee(Model.Employees employee)
{
try
{
string sql = "insert into Employees ([FirstName],[LastName],[Gender],[DOB],[Language],[Nationality],[Address]) values ";
sql += "('" + employee.FirstName + "','" + employee.LastName + "','" + employee.Gender + "',";
sql += "'" + employee.DOB + "','" + employee.Language + "','" + employee.Nationality + "'";
sql += ",'" + employee.Address + "')";
DBConnections.InserQuery(sql);
MessageBox.Show("Data Saved Successfully.");
}
catch (SqlException ex)
{
throw ex;
}
finally
{
}
}
internal static void UpdateEmployee(Model.Employees employee)
{
try
{
string sql = "Update Employees set [FirstName]='" + employee.FirstName + "',[LastName]='" + employee.LastName + "',";
sql += "[Gender] ='" + employee.Gender + "',[DOB]='" + employee.DOB + "',[Language]='" + employee.Language + "',";
sql += "[Nationality]='" + employee.Nationality + "',[Address]='" + employee.Address + "' where [ID]='" + employee.ID + "'";
DBConnections.UpdateQuery(sql);
MessageBox.Show("Data Updated Successfully.");
}
catch (SqlException ex)
{
throw ex;
}
finally
{
}
}
internal static void DeleteEmployee(Model.Employees employee)
{
try
{
string sql = "Delete * from Employees where ID='" + employee.ID + "'";
DBConnections.DeleteQuery(sql);
MessageBox.Show("Data Deleted Successfully.");
}
catch (SqlException ex)
{
throw ex;
}
finally
{
}
}
}
MY VIEW ( SHOW EMPLOYEES LIST)
<Window x:Class="EditaWPF01.NewTest.View.EmployeePage"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:EditaWPF01.NewTest.View"
xmlns:vm="clr-namespace:EditaWPF01.NewTest.ViewModel"
mc:Ignorable="d"
Title="Employees" Height="450" Width="800" WindowStartupLocation="CenterScreen">
<Window.DataContext>
<vm:EditaEmployeesViewModel/>
</Window.DataContext>
<Grid>
<GroupBox Header="Employees List" Margin="5">
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="27"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ToolBarTray >
<ToolBar >
<Button x:Name="tlNewGas" ToolTip="New Gas" VerticalAlignment="Center" Padding="0"
Command="{Binding NewEmployeeButton}">
<Image Source=".PicsFile_20px.png" />
</Button>
<Separator/>
<Button x:Name="tlUpdateGas" ToolTip="Update Gas" VerticalAlignment="Center" Padding="0"
Command="{Binding UpdateEmployeeButton}">
<Image Source=".PicsEdit File_20px.png"/>
</Button>
<Separator/>
<Button x:Name="btnDelete" ToolTip="Delete Gas" VerticalAlignment="Center" Padding="0"
Content="Delete" Command="{Binding DeleteEmployeeButton}"/>
</ToolBar>
</ToolBarTray>
<DataGrid Grid.Row="1" AutoGenerateColumns="False" ItemsSource="{Binding EmployeeList}" CanUserAddRows="False">
<DataGrid.Columns>
<DataGridTextColumn Header="F.Name" Binding="{Binding Path=FirstName}"/>
<DataGridTextColumn Header="L.Name" Binding="{Binding LastName}"/>
<DataGridTextColumn Header="Address" Binding="{Binding Address}"/>
<DataGridTextColumn Header="DOB" Binding="{Binding DOB}"/>
<DataGridTextColumn Header="Gender" Binding="{Binding Gender}"/>
<DataGridTextColumn Header="Nationality" Binding="{Binding Nationality}"/>
<DataGridTextColumn Header="Language" Binding="{Binding Language}"/>
</DataGrid.Columns>
</DataGrid>
</Grid>
</GroupBox>
</Grid>
MY FORM TO ADD NEW EMPLOYEE
<Window x:Class="EditaWPF01.NewTest.View.AddUpdateEmployee"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:local="clr-namespace:EditaWPF01.NewTest.View"
xmlns:vm="clr-namespace:EditaWPF01.NewTest.ViewModel"
mc:Ignorable="d"
Title="Add/Update Employee" Height="450" Width="500" WindowStartupLocation="CenterScreen">
<Window.DataContext>
<vm:EditaEmployeesViewModel/>
</Window.DataContext>
<Grid>
<Grid.RowDefinitions>
<RowDefinition Height="27"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
<ToolBarTray Background="Orange">
<ToolBar Background="Orange">
<Button x:Name="tlNewGas" ToolTip="New Gas" VerticalAlignment="Center"
Padding="0" Content="Save" Height="27" Command="{Binding SaveNewEmployeeButton}"/>
</ToolBar>
</ToolBarTray>
<Grid Grid.Row="1">
<Grid.RowDefinitions>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
<RowDefinition/>
</Grid.RowDefinitions>
<Grid.ColumnDefinitions>
<ColumnDefinition Width="150"/>
<ColumnDefinition/>
</Grid.ColumnDefinitions>
<TextBlock Text="First Name :" Grid.Row="0" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="0" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding FirstName, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="Last Name :" Grid.Row="1" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="1" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding LastName, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="Address :" Grid.Row="2" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="2" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding Address, BindingGroupName=Group1, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="DOB :" Grid.Row="3" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="3" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding DOB, BindingGroupName=Group1, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="Language :" Grid.Row="4" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="4" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding Language, BindingGroupName=Group1, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="Nationality :" Grid.Row="5" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="5" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding Nationality, BindingGroupName=Group1, UpdateSourceTrigger=Explicit}"/>
<TextBlock Text="Gender :" Grid.Row="6" Grid.Column="0" VerticalAlignment="Center"
HorizontalAlignment="Center"/>
<TextBox Grid.Row="6" Grid.Column="1" VerticalAlignment="Center"
Text="{Binding Gender, UpdateSourceTrigger=Explicit}"/>
</Grid>
</Grid>
我把saveNewEmployee的命令留空了，我不知道如何完成
您的问题可能出在UpdateSourceTrigger=Explicit。除非你明确更新，否则你的源代码永远不会更新。
请参阅https://learn.microsoft.com/en-us/dotnet/framework/wpf/data/how-to-control-when-the-textbox-text-updates-the-source