我正在开发一个小型的wpf项目来更好地理解c#和mvvm。 我目前有一个问题,我不知道如何在两个页面之间传递数据。 我想做的事: 我有两页,它们是我的MainWindow的内容。 在PageViewCustomers我有一个DatagridView(有两个,但我只需要一个用于此任务),当我双击一行时,我打开PageAddStaticIPAddress。现在我希望能够访问我在PageAddStaticIPAddress中的PageViewCustomers中双击的行。我想过将所选行作为CommandParameter传递给PageViewCustomers的xaml。 但现在我不知道如何从PageAddStaticIPAddress访问它.. 我已经看到了一些解决方案,但它们都通过在视图中使用Code来解决它。我尝试尽可能减少视图中的代码,并仅使用Bindings,命令和我的视图模型来解决它。
这是我目前的代码:
PageViewCustomers.xaml
<Page x:Class="StaticIPConfiger.PageViewCustomers"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:StaticIPConfiger"
xmlns:localvm="clr-namespace:StaticIPConfiger.Modelle"
xmlns:i="clr-namespace:System.Windows.Interactivity;assembly=System.Windows.Interactivity"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="500"
Title="Kundenübersicht">
<Page.DataContext>
<localvm:VModel />
</Page.DataContext>
<Grid DataContext="{Binding}" >
<DataGrid IsReadOnly="True" Name="dgCustomers" ItemsSource="{Binding AlleKunden}" AutoGenerateColumns="False" Margin="0,0,0,197">
<DataGrid.Columns>
<DataGridTextColumn Header="Name" Binding="{Binding Path=c_name}" Width="*"></DataGridTextColumn>
<DataGridTextColumn Header="Standort" Binding="{Binding Path=l_name}" Width="*"></DataGridTextColumn>
</DataGrid.Columns>
<i:Interaction.Triggers>
<i:EventTrigger EventName="SelectionChanged">
<i:InvokeCommandAction Command="{Binding UpdateLocations}"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}, Path=SelectedItem}" />
</i:EventTrigger>
</i:Interaction.Triggers>
</DataGrid>
<DataGrid IsReadOnly="True" Name="dg2Customers" ItemsSource="{Binding AlleStandorte}" AutoGenerateColumns="False" Margin="0,168,0,10" >
<DataGrid.InputBindings>
<MouseBinding Gesture="LeftDoubleClick" Command="{Binding OpenAddNewIPAddress}"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}, Path=SelectedItem}"/>
</DataGrid.InputBindings>
<DataGrid.Columns>
<DataGridTextColumn Header="StandortId" Binding="{Binding Path=l_id}" Width="*"></DataGridTextColumn>
<DataGridTextColumn Header="Standort" Binding="{Binding Path=l_name}" Width="*"></DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
</Grid>
类VModel.cs(PageViewCustomers的VModel)
namespace StaticIPConfiger.Modelle {
public class VModel : INotifyPropertyChanged {
DataView _alleKunden;
public VModel() {
DataTable dt = new DataTable();
using (SqlConnection connection = new SqlConnection("Data Source=.\\WERBASWEB;Initial Catalog=customer;Persist Security Info=True;User ID=sa;Password=Dotnet123!")) {
SqlDataAdapter adapter = new SqlDataAdapter();
adapter.SelectCommand = new SqlCommand("Select c_id,c_name, l_id,l_name, a_town, a_pcode, a_street from dbo.[AllCustomers]", connection);
adapter.Fill(dt);
}
AlleKunden = dt.DefaultView;
AlleStandorte = null;
}
public DataView AlleKunden { get; private set; }
public DataView AlleStandorte { get { return _alleKunden; } private set { _alleKunden = value;
RaisePropertyChanged("AlleStandorte");
} }
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
#endregion
#region Methods
private void RaisePropertyChanged(string propertyName) {
// take a copy to prevent thread issues
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) {
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
#region Commands
void UpdateLocationView(object parameter) {
DataRowView selectedRow = (DataRowView)parameter;
string customerid = selectedRow.Row[0].ToString();
string locationid = selectedRow.Row[2].ToString();
DataTable dt = SelectStatements.SelectLocationsForCustomer(locationid,customerid);
AlleStandorte = dt.DefaultView;
Console.WriteLine("Test");
}
bool CanUpdateLocationView(object parameter) {
return true;
}
public ICommand UpdateLocations { get { return new RelayCommand<object>(param => this.UpdateLocationView(param), param => this.CanUpdateLocationView(param)); } }
void OpenIPAddress() {
System.Windows.Application.Current.MainWindow.Content = new AddStaticIPAddress();
}
bool CanOpenIPAddress() {
return true;
}
public ICommand OpenAddNewIPAddress { get { return new RelayCommand(OpenIPAddress,CanOpenIPAddress); } }
#endregion
}
Page AddStaticIPAddress:
<Page x:Class="StaticIPConfiger.AddStaticIPAddress"
xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
xmlns:local="clr-namespace:StaticIPConfiger"
mc:Ignorable="d"
d:DesignHeight="300" d:DesignWidth="500"
Title="AddStaticIPAddress">
<Page.DataContext>
<local:AddCustomerVModel/>
</Page.DataContext>
<Grid>
<Label x:Name="lbl_net" Content="Netz:" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
<Label x:Name="lbl_subnetmask" Content="Subetnmaske:" HorizontalAlignment="Left" VerticalAlignment="Top" Margin="10,36,0,0"/>
<Label x:Name="label_ipaddress" Content="IP Addresse:" HorizontalAlignment="Left" Margin="10,62,0,0" VerticalAlignment="Top"/>
<TextBox x:Name="text_net" Text="" HorizontalAlignment="Left" Height="23" Margin="103,10,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
<TextBox x:Name="text_subetnmask" Text="" HorizontalAlignment="Left" Height="23" Margin="103,36,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
<TextBox x:Name="text_ipaddress" Text="" HorizontalAlignment="Left" Height="23" Margin="103,62,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
<Label x:Name="lbl_description" Content="Bezeichnung:" HorizontalAlignment="Left" Margin="10,85,0,0" VerticalAlignment="Top"/>
<TextBox x:Name="text_description" Text="" HorizontalAlignment="Left" Height="23" Margin="103,88,0,0" TextWrapping="Wrap" VerticalAlignment="Top" Width="120"/>
<Button x:Name="btn_save_add_ip" Content="IP Addresse hinzufügen" Command ="" HorizontalAlignment="Left" Margin="10,129,0,0" VerticalAlignment="Top" Width="133"/>
<Button x:Name="btn_abort_add_ip" Content="Verwerfen" HorizontalAlignment="Left" Margin="148,129,0,0" VerticalAlignment="Top" Width="75"/>
</Grid>
AddIPAddressVModel:
namespace StaticIPConfiger.Modelle {
class AddIPAddressVModel : INotifyPropertyChanged {
IPAddress _ipaddress;
public AddIPAddressVModel() {
_ipaddress = new IPAddress { Net = "", Subetnmask = "", IpAddress = ""};
}
public IPAddress IPAddress {
get { return _ipaddress; }
set { _ipaddress = value; }
}
#region"Get/Set"
public int Id {
get { return IPAddress.Id; }
set {
IPAddress.Id = value;
RaisePropertyChanged("IPAddress");
}
}
public String Net {
get { return IPAddress.Net; }
set {
IPAddress.Net= value;
RaisePropertyChanged("Net");
}
}
public string Subnetmask {
get { return IPAddress.Subetnmask; }
set {
IPAddress.Subetnmask = value;
RaisePropertyChanged("Subetnmask");
}
}
public string IpAddress {
get { return IPAddress.IpAddress; }
set {
IPAddress.IpAddress = value;
RaisePropertyChanged("IPAddress");
}
}
#endregion
#region INotifyPropertyChanged Members
public event PropertyChangedEventHandler PropertyChanged;
#endregion
#region Methods
private void RaisePropertyChanged(string propertyName) {
// take a copy to prevent thread issues
PropertyChangedEventHandler handler = PropertyChanged;
if (handler != null) {
handler(this, new PropertyChangedEventArgs(propertyName));
}
}
#endregion
}
我希望你理解我的问题;-) 如果您有任何疑问,请告诉我。 谢谢!
编辑: 我如何打开AddIPAddress 我确实将一个Command绑定到DataGrid,我有一个Command OpenAddNewIPAddress:
<DataGrid.InputBindings>
<MouseBinding Gesture="LeftDoubleClick" Command="{Binding OpenAddNewIPAddress}"
CommandParameter="{Binding RelativeSource={RelativeSource FindAncestor, AncestorType={x:Type DataGrid}}, Path=SelectedItem}"/>
</DataGrid.InputBindings>
命令如下所示:
void OpenIPAddress() {
System.Windows.Application.Current.MainWindow.Content = new AddStaticIPAddress();
}
bool CanOpenIPAddress() {
return true;
}
public ICommand OpenAddNewIPAddress { get { return new RelayCommand(OpenIPAddress,CanOpenIPAddress); } }
我有另一个问题。当我用新的页面设置我的MainWindow(System.Windows.Application.Current.MainWindow.Content = new AddStaticIPAddress();)的内容时,菜单栏会丢失...有更好的方法吗?
答案 0 :(得分:1)
您可以使用command参数注入AddIPAddressVModel。像这样:
<DataGrid IsReadOnly="True" Name="dg2Customers" ItemsSource="{Binding AlleStandorte}" AutoGenerateColumns="False" Margin="0,168,0,10" >
<DataGrid.InputBindings>
<MouseBinding Gesture="LeftDoubleClick" Command="{Binding OpenAddNewIPAddress}"CommandParameter="{Binding SelectedItem}"/>
</DataGrid.InputBindings>
<DataGrid.Columns>
<DataGridTextColumn Header="StandortId" Binding="{Binding Path=l_id}" Width="*"></DataGridTextColumn>
<DataGridTextColumn Header="Standort" Binding="{Binding Path=l_name}" Width="*"></DataGridTextColumn>
</DataGrid.Columns>
</DataGrid>
void OpenIPAddress(object parameter)
{
System.Windows.Application.Current.MainWindow.DataContext = new AddIPAddressVModel(parameter as DataRowView)
System.Windows.Application.Current.MainWindow.Content = new AddStaticIPAddress();
}
bool CanOpenIPAddress(object parameter)
{
return true;
}
public ICommand OpenAddNewIPAddress { get { return new RelayCommand<object>(OpenIPAddress, CanOpenIPAddress); } }
public AddIPAddressVModel(DataRowView drv) {
_ipaddress = new IPAddress { Net = "", Subetnmask = "", IpAddress = ""};
_drv = drv; //keep a reference to the clicked DataRowView
}
从AddStaticIPAddress视图中删除它:
<Page.DataContext>
<local:AddCustomerVModel/>
</Page.DataContext>
Page应继承其DataContext。在XAML标记中设置DataContext仅在视图模型没有依赖项的非常简单的情况下才有用。
答案 1 :(得分:0)
尝试在AddStaticIPAddress
中添加字段:
public DataGridRow Row { get; set; }
因此,您可以从VModel
访问它。
例如。您可以在AddIPAddressVModel
操作上初始化DataGridSelectionChanged
:
private void dgCustomers_OnSelectionChanged(...)
{
AddIPAddressVModel addip = new AddIPAddressVModel();
addip.Row = (DataGridRow) dgCustomers.SelectedItem;
addip.Show();
}