我希望能够在我的WPF Datagrid中显示一个SQL表格,运行时编写SQL查询语句。 我已经建立了我的视图(简化版)和关联的ViewModel:
视图:
-----------------MyDataGrid.xaml-----------------
<DataGrid x:Name="CurrentSqlGrid"
ItemsSource="{Binding Path=CurrentDataTable,Mode=OneWay}"
Grid.Row="2" AutoGenerateColumns="True" IsReadOnly="True" />
<TextBox x:Name="TextBoxSql" Height="120" Grid.Row="1"
TextWrapping="Wrap" VerticalAlignment="Top"/>
-----------------MyDataGrid.cs-----------------
public partial class MyDataGrid : UserControl
{
private SqlDataGridViewModel sqlDataGridViewModel;
public MyDataGrid()
{
InitializeComponent();
sqlDataGridViewModel = new SqlDataGridViewModel();
this.DataContext = sqlDataGridViewModel;
}
private void Button_Click_1(object sender, RoutedEventArgs e)
{
sqlDataGridViewModel.FillDataTableWithQuery(TextBoxSql.Text);
}
}
视图模型:
-----------------SqlDataGridViewModel.cs-----------------
public class SqlDataGridViewModel
{
private DataTable _dataTable;
private SqlDataAdapter _adapter;
public DataTable CurrentDataTable
{
get
{
return _dataTable;
}
set
{
_dataTable = value;
}
}
public SqlDataGridViewModel()
{
_dataTable = new DataTable("QUERY");
FillDataTableWithQuery("SELECT TOP 500 * FROM XUSER");
}
public void FillDataTableWithQuery(string query)
{
CurrentDataTable.Reset();
CurrentDataTable.Clear();
try
{
using (SqlConnection sqlConn = new SqlConnection(SessionProvider.Instance.currentConnectionString))
{
_adapter = new SqlDataAdapter(query, sqlConn);
_adapter.Fill(CurrentDataTable);
}
}
catch (Exception ex)
{
MartuLogger.Instance.Error("Exception in SqlDataGridViewModel :" + ex.Message);
}
}
}
这个解决方案显示了第一个查询的第一个数据表。但是当我编写另一个SQL查询时,我调用
FillDataTableWithQuery("SELECT * from another_table")
并且Datagrid清除了所有行,但它不会加载新列和新行!(仅显示旧列!)。在调试中,CurrentDataTable
包含新查询的结果.... 任何想法?
解决方案
在Faisal Hafeez的帮助下,我们找到了这个解决方案:Xaml和代码后端是相同的。 它可以使用OneWay和TwoWay模式。
我的视图模型变成:
public class SqlDataGridViewModel : INotifyPropertyChanged
{
private DataTable _dataTable;
private SqlDataAdapter _adapter;
public event PropertyChangedEventHandler PropertyChanged;
protected void NotifyPropertyChange(string PropertyName)
{
PropertyChanged(this, new PropertyChangedEventArgs(PropertyName));
}
public DataTable CurrentDataTable
{
get
{
return _dataTable;
}
set
{
_dataTable = value;
//NotifyPropertyChange("CurrentDataTable");
}
}
public SqlDataGridViewModel()
{
_dataTable = new DataTable("QUERY");
FillDataTableWithQuery("SELECT TOP 500 * FROM XUSER");
}
public void FillDataTableWithQuery(string query)
{
_dataTable = new DataTable("QUERY");
try
{
using (SqlConnection sqlConn = new SqlConnection(SessionProvider.Instance.currentConnectionString))
{
_adapter = new SqlDataAdapter(query, sqlConn);
_adapter.Fill(CurrentDataTable);
}
NotifyPropertyChange("CurrentDataTable");
}
catch (Exception ex)
{
MartuLogger.Instance.Error("Exception in SqlDataGridViewModel :" + ex.Message);
}
}
}
如果我在_adapter.Fill之后不通知NotifyPropertyChange,则视图不会刷新。(我已尝试在Set CurrentTable中通知,但_adapter.Fill显然不调用CurrentTable的set方法)。 谢谢。