WPF BindingSource

Question

通过从WinForms转换我的一个应用程序来学习WPF -- WPF的方法是什么？

 DataTable _current = _connections.Copy();
 BindingSource _bs = new BindingSource();
 bs.DataSource = _current;
 bs.Filter = "Client = '" + _selectedClient + "'";

在对新的DataTable表进行过滤之后，我需要将绑定源分配给DataGrid。

更新2我添加了以下内容

 public ObservableCollection<SupportConnectionData> _supportConnections = new ObservableCollection<SupportConnectionData>();

将给定的数据表转换为ObservableCollection

 DataTable _dt = Global.RequestSupportConnections(_token);
                _dt = Crypto.DecryptDataTable(_dt);
                ObservableCollection<SupportConnectionData> _connections = new ObservableCollection<SupportConnectionData>();

                foreach (DataRow _row in _dt.Rows)
                {
                    SupportConnectionData _supportConnection = new SupportConnectionData()
                    {
                        _client = _row["Client"].ToString(),
                        _server = _row["Server"].ToString(),
                        _user = _row["User"].ToString(),
                        _connected = _row["Connected"].ToString(),
                        _disconnected = _row["Disconnected"].ToString(),
                        _reason = _row["Reason"].ToString(),
                        _caseNumber = _row["CaseNumber"].ToString()
                    };
                    _connections.Add(_supportConnection);
                }

                //let me assign new collection to bound collection
                App.Current.Dispatcher.BeginInvoke((Action)(() => { _supportConnections = _connections; }));
                //this allows it to update changes to ui
                dgSupportConnections.Dispatcher.BeginInvoke((Action)(() => { dgSupportConnections.DataContext = _supportConnections; }));

XAML

  <DataGrid x:Name="dgSupportConnections" HorizontalAlignment="Stretch" Margin="0,0,0,0" VerticalAlignment="Stretch" AutoGenerateColumns="False" ItemsSource="{Binding}">
                    <DataGrid.Columns>
                        <DataGridTextColumn Header="Client" Binding="{Binding _client}"/>
                        <DataGridTextColumn Header="Server" Binding="{Binding _server}"/>
                        <DataGridTextColumn Header="User" Binding="{Binding _user}"/>
                        <DataGridTextColumn Header="Connected" Binding="{Binding _connected}"/>
                        <DataGridTextColumn Header="Disconnected" Binding="{Binding _disconnected}"/>
                        <DataGridTextColumn Header="Reason" Binding="{Binding _reason}"/>
                        <DataGridTextColumn Header="Case Number" Binding="{Binding _caseNumber}"/>
                    </DataGrid.Columns>
                </DataGrid>

Answer 1

将数据库对象(或以何种方式获取它们)放入集合(例如MyCollection作为类型的ObservableCollection )或集合视图源，然后绑定到该集合中。在wpf中，您必须处理绑定xaml视图的类的上下文。因此，如果数据集的直接上下文是后面的代码，那么您可以将这一行添加到datagrid中，以便绑定到集合：

<DataGrid ItemsSource="{Binding MyCollection}" / >

在win forms中，您可以在代码中将集合分配给datagirid，但是在WPF中，您可以在xaml中声明绑定，而"WPF引擎“则负责其余的绑定。有一点学习曲线，但它确实是灵活的，在我看来，减少了代码。

但这引发了对应用程序体系结构的更大讨论。我建议查看MVVM，以便在模型(数据)、视图(用户界面)和ViewModel (处理业务逻辑)之间创建关注点的解耦或分离。THis将使您的应用程序更易于维护和可测试。

编辑1:示例

窗口的xaml：

<Window x:Class="MainWindow"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="MainWindow" Height="350" Width="525">
    <Grid>
        <DataGrid x:Name="MyDataGrid" AutoGenerateColumns="True" ItemsSource="{Binding MyObjectCollection}" DataContext="{Binding}"  />
    </Grid>
</Window>

Xaml窗口后面的代码：

using Microsoft.VisualBasic;
using System;
using System.Collections;
using System.Collections.Generic;
using System.Data;
using System.Diagnostics;
using System.Collections.ObjectModel;

class MainWindow
{


    public ObservableCollection<MyObject> MyObjectCollection = new ObservableCollection<MyObject>();

    public MainWindow()
    {
        // This call is required by the designer.
        InitializeComponent();

        // Add any initialization after the InitializeComponent() call.
        for (i = 1; i <= 10; i++) {
            MyObject newObject = new MyObject {
                age = i,
                name = "Full Name"
            };
            MyObjectCollection.Add(newObject);
        }


        MyDataGrid.ItemsSource = MyObjectCollection;
    }
}

public class MyObject
{
    public string name { get; set; }
    public string age { get; set; }
}

虽然此示例适用于学习，但我不建议这种方法用于生产应用程序。我认为您需要了解MVVM，或者MVC，以便有一个可维护和可测试的应用程序。