WPF中的DataGrid和Observable Collection

Question

我的WPF应用程序中有一个如下所示的数据网格.

<Window x:Class="MyApp.TestWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">
    <Grid>
    <DataGrid x:Name="dgTest"  ItemsSource="{Binding TestSource}" AutoGenerateColumns="False" >
            <DataGrid.Columns>
                <DataGridTemplateColumn Width="125" >
                       <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                                      <TextBox Text="{Binding Column1}"></TextBox>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
                <DataGridTemplateColumn Width="500" >
                    <DataGridTemplateColumn.CellTemplate>
                        <DataTemplate>
                            <TextBox Text="{Binding Column2}"></TextBox>
                        </DataTemplate>
                    </DataGridTemplateColumn.CellTemplate>
                </DataGridTemplateColumn>
            </DataGrid.Columns>
        </DataGrid>
         <Button Click="SaveButton_Click">Save</Button>
    </Grid>
</Window>

我使用以下代码绑定它.现在我的要求是当用户在datagrid中的这些文本框中输入一些文本并单击"保存"按钮时,它应该更新数据库.我怎样才能做到这一点？

namespace MyApp
{
    public partial class TestWindow: Window
    {
        private ObservableCollection<Test> _testSource
        public ObservableCollection<Test> TestSource
        {
            get
            {
                return _testSource;
            }
            set
            {
                _testSource = value;
                OnPropertyChanged("TestSource");
            }
        }

        public event PropertyChangedEventHandler PropertyChanged;
        private void OnPropertyChanged(string propName)
        {
            if (PropertyChanged != null)
            {
                PropertyChanged.Invoke(this, new PropertyChangedEventArgs(propName));
            }
        }

        public TestWindow()
        {
            InitializeComponent();
            TestSource= new ObservableCollection<Test>();
             string strConnString = Application.Current.Properties["connectionStr"].ToString();
             SqlConnection con = new SqlConnection(strConnString);
            SqlCommand cmd = new SqlCommand("SELECT Column1,Column2 FROM MyTable", con);
            SqlDataAdapter da = new SqlDataAdapter(cmd);
            DataTable dtTest = new DataTable();
            da.Fill(dtTest);
            foreach (DataRow row in dtTest)
            {
                Test cd = new Test();
                cd.Column1 = row["Column1"].ToString();
                cd.Column2 = row["Column2"].ToString();
                TestSource.Add(cd);
            }
            this.DataContext = this;
        }

        private void SaveButton_Click(object sender, RoutedEventArgs e)
        {
             // here I need to get the updated ObservableCollection, but now it is showing old data
             foreach Test t in TestSource)
            {
                string a = t.Column1;
                string b = t.Column2;
            }
        }
    }

    public class Test: 
    {
        public string Column1{ get; set; }
        public string Column2{ get; set; }
    }
}

谢谢

Answer 1

在DataGridTemplateColumn(或者自定义DataGrid.RowStyle)中创建自己的UI UpdateSourceTrigger时,Explicit如果您没有自己指定,DataGrid会更改所有绑定的基础数据(即基础数据应该更新时).

这个"功能"在这里简要描述:5随机问题与WPF DataGrid,即使作者说无论你是否设置UpdateSourceTrigger自己发生这种情况,自己设置确实有效(至少在.Net 4.0中).

使用LostFocus模拟的默认TextBox行为(与PropertyChanged上CheckBox等):

...
<TextBox Text="{Binding Column1, UpdateSourceTrigger=LostFocus}"></TextBox>
...
<TextBox Text="{Binding Column2, UpdateSourceTrigger=LostFocus}"></TextBox>
...