c# - 通过以编程方式搜索字符串来选择 dataGrid 中的一行

Question

我有一个名为“txtSearch”的文本框

我还有一个以编程方式填充的 DataGrid。

现在我想在 DataGridView 中搜索 txtSearch.text 并基于此选择整行。

我希望它以编程方式完成。我的意思是不使用 XAML。

是否可以？

Answer 1

首先，如果你在 WPF 中做某事，你最好用 WPF Way来做。

如果您对学习 XAML 和 MVVM 不感兴趣，那么您宁愿回到恐龙无用的技术。

<Window x:Class="MiscSamples.DataGridSearch"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        Title="DataGridSearch" Height="300" Width="300">
    <DockPanel>
        <DockPanel DockPanel.Dock="Top">
            <TextBlock Text="Search:" DockPanel.Dock="Left"/>
            <TextBox Text="{Binding SearchString, UpdateSourceTrigger=PropertyChanged}"/>
        </DockPanel>

        <DataGrid ItemsSource="{Binding ItemsView}" AutoGenerateColumns="True"/>
    </DockPanel>
</Window>

代码背后：

public partial class DataGridSearch : Window
{
    public DataGridSearch()
    {
        InitializeComponent();

        DataContext = new DataGridSearchViewModel();
    }
}

视图模型：

public class DataGridSearchViewModel: PropertyChangedBase
{
    private string _searchString;
    public string SearchString
    {
        get { return _searchString; }
        set
        {
            _searchString = value;
            OnPropertyChanged("SearchString");
            ItemsView.Refresh();
        }
    }

    private ICollectionView _itemsView;
    public ICollectionView ItemsView
    {
        get { return _itemsView; }
    }

    private ObservableCollection<DataGridSearchModel> _items;
    public ObservableCollection<DataGridSearchModel> Items
    {
        get { return _items ?? (_items = new ObservableCollection<DataGridSearchModel>()); }
    }

    public DataGridSearchViewModel()
    {
        _itemsView = CollectionViewSource.GetDefaultView(Items);
        _itemsView.Filter = x => Filter(x as DataGridSearchModel);

        Enumerable.Range(0, 100)
                  .Select(x => CreateRandomItem())
                  .ToList()
                  .ForEach(Items.Add);
    }

    private bool Filter(DataGridSearchModel model)
    {
        var searchstring = (SearchString ?? string.Empty).ToLower();

        return model != null &&
             ((model.LastName ?? string.Empty).ToLower().Contains(searchstring) ||
              (model.FirstName ?? string.Empty).ToLower().Contains(searchstring) ||
              (model.Address ?? string.Empty).ToLower().Contains(searchstring));
    }

    private DataGridSearchModel CreateRandomItem()
    {
        return new DataGridSearchModel
                   {
                       LastName = RandomGenerator.GetNext(1),
                       FirstName = RandomGenerator.GetNext(1),
                       Address = RandomGenerator.GetNext(4)
                   };
    }
}

数据项：

public class DataGridSearchModel:PropertyChangedBase
{
    public string LastName { get; set; }

    public string FirstName { get; set; }

    public string Address { get; set; }
}

PropertyChangedBase（MVVM 助手类）：

public class PropertyChangedBase:INotifyPropertyChanged
{
    public event PropertyChangedEventHandler PropertyChanged;

    protected virtual void OnPropertyChanged(string propertyName)
    {
        Application.Current.Dispatcher.BeginInvoke((Action) (() =>
                                                                 {
                                                                     PropertyChangedEventHandler handler = PropertyChanged;
                                                                     if (handler != null) handler(this, new PropertyChangedEventArgs(propertyName));
                                                                 }));
    }
}

随机生成器（仅用于生成随机字符串）

public static class RandomGenerator
{
    private static string TestData = "Lorem ipsum dolor sit amet, consectetur adipisicing elit, sed do eiusmod tempor incididunt ut labore et dolore magna aliqua. Ut enim ad minim veniam, quis nostrud exercitation ullamco laboris nisi ut aliquip ex ea commodo consequat. Duis aute irure dolor in reprehenderit in voluptate velit esse cillum dolore eu fugiat nulla pariatur. Excepteur sint occaecat cupidatat non proident, sunt in culpa qui officia deserunt mollit anim id est laborum";
    private static List<string> words;
    private static int maxword;
    private static Random random = new Random();

    static RandomGenerator()
    {
        words = TestData.Split(' ').ToList();
        maxword = words.Count - 1;
    }

    public static string GetNext(int wordcount)
    {
        return string.Join(" ", Enumerable.Range(0, wordcount)
                                          .Select(x => words[random.Next(0, maxword)]));
    }

    public static int GetNextInt(int min, int max)
    {
        return random.Next(min, max);
    }
}

结果：

• 完全 MVVM。
• 没有一行代码可以操作任何 UI 元素。这是 WPF 的方式。
• UpdateSourceTrigger=PropertyChanged在TextBox绑定中使其在您键入时进行搜索。
• 完全强类型的对象模型比使用DataTables和类似的东西要好得多。
• WPF 摇滚。只需将我的代码复制并粘贴到 a 中File -> New Project -> WPF Application，然后自己查看结果。
• 忘记winforms的心态吧，它无关紧要，笨拙，生成糟糕的代码，只是觉得菜鸟和不成熟。

Answer 2

你可能想使用像 ff.data 那样的数据绑定。下面的代码

Dim m_Dt As New DataTable
Dim m_Bs As New BindingSource

Private Sub createDatatable()
    m_Dt.Columns.Clear()
    m_Dt.Columns.Add("FieldKey", GetType(System.Int16))
    m_Dt.Columns.Add("Field1", GetType(System.String))
    m_Dt.Columns.Add("Field2", GetType(System.String))
End Sub

Private Sub PopulateDatatable()
    For i As Integer = 0 To 10
        Dim dr As DataRow = m_Dt.NewRow
        dr("FieldKey") = i
        dr("Field1") = String.Format("field1Value-{0}", i)
        dr("field2") = String.Format("Field2Value-{0}", i)
        dr = m_Dt.Rows.Add
    Next

End Sub

Private Sub BindDatatableToDataGridView()
    m_Bs.DataSource = m_Dt
    m_DataGridview.DataSource = m_Bs
End Sub

Private Sub FindTextAndFocusOnRow()
    m_Bs.Position = m_Bs.Find("FieldKey", m_TxtSearchText.Text)
End Sub


Private Sub ModifyRowValues()
    m_Dt.Rows(m_Bs.Position)("Field1") = "FieldModified"
End Sub