SearchDirectionHint Enumerazione

Definizione

Spazio dei nomi:

System.Windows.Forms

Assembly:

System.Windows.Forms.dll

Fornisce un suggerimento sulla direzione in cui cercare un oggetto ListViewItem.

public enum class SearchDirectionHint

public enum SearchDirectionHint

type SearchDirectionHint = 

Public Enum SearchDirectionHint

Ereditarietà

Object

ValueType

Enum

SearchDirectionHint

Campi

Down	40	Sotto all'elemento corrente.
Left	37	Alla sinistra dell'elemento corrente.
Right	39	Alla destra dell'elemento corrente.
Up	38	Sopra l'elemento corrente.

Esempio

Nell'esempio di codice seguente viene illustrato come usare l'enumerazione SearchDirectionHint . Per eseguire questo esempio, incollare il codice seguente in un Windows Form e chiamare InitializeLocationSearchListView dal costruttore del modulo o Load dal metodo di gestione degli eventi.

    ListView^ iconListView;
    TextBox^ previousItemBox;

private:
    void InitializeLocationSearchListView()
    {
        previousItemBox = gcnew TextBox();
        iconListView = gcnew ListView();
        previousItemBox->Location = Point(150, 20);

        // Create an image list for the icon ListView.
        iconListView->SmallImageList = gcnew ImageList();

        // Add an image to the ListView small icon list.
        iconListView->SmallImageList->Images->Add(
            gcnew Bitmap(Control::typeid, "Edit.bmp"));

        // Set the view to small icon and add some items with the image
        // in the image list.
        iconListView->View = View::SmallIcon;
        iconListView->Items->AddRange(gcnew array<ListViewItem^>{
            gcnew ListViewItem("Amy Alberts", 0),
            gcnew ListViewItem("Amy Recker", 0),
            gcnew ListViewItem("Erin Hagens", 0),
            gcnew ListViewItem("Barry Johnson", 0),
            gcnew ListViewItem("Jay Hamlin", 0),
            gcnew ListViewItem("Brian Valentine", 0),
            gcnew ListViewItem("Brian Welker", 0),
            gcnew ListViewItem("Daniel Weisman", 0) });
         this->Controls->Add(iconListView);
         this->Controls->Add(previousItemBox);

         // Handle the MouseDown event to capture user input.
         iconListView->MouseDown += gcnew MouseEventHandler(
             this, &Form1::iconListView_MouseDown);
    }

    void iconListView_MouseDown(Object^ sender, MouseEventArgs^ e)
    {
        // Find the next item up from where the user clicked.
        ListViewItem^ foundItem = iconListView->FindNearestItem(
            SearchDirectionHint::Up, e->X, e->Y);

        // Display the results in a textbox..
        if (foundItem != nullptr)
        {
            previousItemBox->Text = foundItem->Text;
        }
        else
        {
            previousItemBox->Text = "No item found";
        }
    }

ListView iconListView = new ListView();
TextBox previousItemBox = new TextBox();

private void InitializeLocationSearchListView()
{
    previousItemBox.Location = new Point(150, 20);

    // Create an image list for the icon ListView.
    iconListView.LargeImageList = new ImageList();
    iconListView.Height = 400;
    
    // Add an image to the ListView large icon list.
    iconListView.LargeImageList.Images.Add(
        new Bitmap(typeof(Control), "Edit.bmp"));

    // Set the view to large icon and add some items with the image
    // in the image list.
    iconListView.View = View.LargeIcon;
    iconListView.Items.AddRange(new ListViewItem[]{
        new ListViewItem("Amy Alberts", 0), 
        new ListViewItem("Amy Recker", 0), 
        new ListViewItem("Erin Hagens", 0), 
        new ListViewItem("Barry Johnson", 0), 
        new ListViewItem("Jay Hamlin", 0), 
        new ListViewItem("Brian Valentine", 0), 
        new ListViewItem("Brian Welker", 0), 
        new ListViewItem("Daniel Weisman", 0) });
    this.Controls.Add(iconListView);
    this.Controls.Add(previousItemBox);

    // Handle the MouseDown event to capture user input.
   iconListView.MouseDown +=
       new MouseEventHandler(iconListView_MouseDown);
    //iconListView.MouseWheel += new MouseEventHandler(iconListView_MouseWheel);   
}

void iconListView_MouseDown(object sender, MouseEventArgs e)
{
    
    // Find the an item above where the user clicked.
    ListViewItem foundItem =
        iconListView.FindNearestItem(SearchDirectionHint.Up, e.X, e.Y);

    // Display the results in a textbox..
    if (foundItem != null)
        previousItemBox.Text = foundItem.Text;
    else
        previousItemBox.Text = "No item found";
}

Private WithEvents iconListView As New ListView()
Private previousItemBox As New TextBox()


Private Sub InitializeLocationSearchListView()
    previousItemBox.Location = New Point(150, 20)

    ' Create an image list for the icon ListView.
    iconListView.LargeImageList = New ImageList()

    ' Add an image to the ListView large icon list.
    iconListView.LargeImageList.Images.Add(New Bitmap(GetType(Control), "Edit.bmp"))

    ' Set the view to large icon and add some items with the image
    ' in the image list.
    iconListView.View = View.SmallIcon
    iconListView.Items.AddRange(New ListViewItem() { _
        New ListViewItem("Amy Alberts", 0), _
        New ListViewItem("Amy Recker", 0), _
        New ListViewItem("Erin Hagens", 0), _
        New ListViewItem("Barry Johnson", 0), _
        New ListViewItem("Jay Hamlin", 0), _
        New ListViewItem("Brian Valentine", 0), _
        New ListViewItem("Brian Welker", 0), _
        New ListViewItem("Daniel Weisman", 0)})

    Me.Controls.Add(iconListView)
    Me.Controls.Add(previousItemBox)
End Sub

Sub iconListView_MouseDown(ByVal sender As Object, ByVal e As MouseEventArgs) _
    Handles iconListView.MouseDown

    ' Find the next item up from where the user clicked.
    Dim foundItem As ListViewItem = _
    iconListView.FindNearestItem(SearchDirectionHint.Up, e.X, e.Y)

    ' Display the results in a textbox.
    If (foundItem IsNot Nothing) Then
        previousItemBox.Text = foundItem.Text
    Else
        previousItemBox.Text = "No item found"
    End If


End Sub

Commenti

Questa enumerazione viene usata dai FindNearestItem metodi nelle ListView classi e, ListViewItem oltre alla SearchForVirtualItemEventArgs classe . L'identificazione dell'elemento più vicino in un ListView controllo può variare a seconda del sistema operativo in cui l'applicazione è in esecuzione. Pertanto, la direzione di ricerca è un hint e non una garanzia assoluta dei risultati.