ListBox.Sort Methode
Definition
Wichtig
Einige Informationen beziehen sich auf Vorabversionen, die vor dem Release ggf. grundlegend überarbeitet werden. Microsoft übernimmt hinsichtlich der hier bereitgestellten Informationen keine Gewährleistungen, seien sie ausdrücklich oder konkludent.
Sortiert die Elemente in der ListBox.
protected:
virtual void Sort();protected virtual void Sort ();abstract member Sort : unit -> unit
override this.Sort : unit -> unitProtected Overridable Sub Sort ()Beispiele
Im folgenden Codebeispiel wird die Verwendung der Sort Methode veranschaulicht. Das Beispiel veranschaulicht das Erben von der ListBox Klasse und überschreiben die Sort Methode in der abgeleiteten Klasse, um eine benutzerdefinierte Sortierung auszuführen. Um dieses Beispiel auszuführen, fügen Sie den folgenden Code in ein leeres Formular ein.
// The following code example demonstrates using the ListBox.Sort method
// by inheriting from the ListBox class and overriding the Sort method.
using namespace System::Drawing;
using namespace System::Windows::Forms;
// This class inherits from ListBox and implements a different
// sorting method. Sort will be called by setting the class's Sorted
// property to True.
public ref class SortByLengthListBox: public ListBox
{
public:
SortByLengthListBox()
: ListBox()
{}
protected:
// Overrides the parent class Sort to perform a simple
// bubble sort on the length of the string contained in each item.
virtual void Sort() override
{
if ( Items->Count > 1 )
{
bool swapped;
do
{
int counter = Items->Count - 1;
swapped = false;
while ( counter > 0 )
{
// Compare the items' length.
if ( Items[ counter ]->ToString()->Length < Items[ counter - 1 ]->ToString()->Length )
{
// Swap the items.
Object^ temp = Items[ counter ];
Items[ counter ] = Items[ counter - 1 ];
Items[ counter - 1 ] = temp;
swapped = true;
}
// Decrement the counter.
counter -= 1;
}
}
while ( (swapped == true) );
}
}
};
public ref class Form1: public System::Windows::Forms::Form
{
internal:
System::Windows::Forms::Button^ Button1;
SortByLengthListBox^ sortingBox;
public:
Form1()
: Form()
{
this->Button1 = gcnew System::Windows::Forms::Button;
this->sortingBox = gcnew SortByLengthListBox;
this->SuspendLayout();
this->Button1->Location = System::Drawing::Point( 64, 16 );
this->Button1->Name = "Button1";
this->Button1->Size = System::Drawing::Size( 176, 23 );
this->Button1->TabIndex = 0;
this->Button1->Text = "Click me for list sorted by length";
this->Button1->Click += gcnew System::EventHandler( this, &Form1::Button1_Click );
array<Object^>^temp0 = {"System","System.Windows.Forms","System.Xml","System.Net","System.Drawing","System.IO"};
this->sortingBox->Items->AddRange( temp0 );
this->sortingBox->Location = System::Drawing::Point( 72, 48 );
this->sortingBox->Size = System::Drawing::Size( 120, 95 );
this->sortingBox->TabIndex = 1;
this->ClientSize = System::Drawing::Size( 292, 266 );
this->Controls->Add( this->sortingBox );
this->Controls->Add( this->Button1 );
this->Name = "Form1";
this->Text = "Sort Example";
this->ResumeLayout( false );
}
private:
void Button1_Click( System::Object^ /*sender*/, System::EventArgs^ /*e*/ )
{
// Set the Sorted property to True to raise the overridden Sort
// method.
sortingBox->Sorted = true;
}
};
int main()
{
Application::Run( gcnew Form1 );
}
// The following code example demonstrates using the ListBox.Sort method
// by inheriting from the ListBox class and overriding the Sort method.
using System.Drawing;
using System.Windows.Forms;
public class Form1:
System.Windows.Forms.Form
{
internal System.Windows.Forms.Button Button1;
internal SortByLengthListBox sortingBox;
public Form1() : base()
{
this.Button1 = new System.Windows.Forms.Button();
this.sortingBox =
new SortByLengthListBox();
this.SuspendLayout();
this.Button1.Location = new System.Drawing.Point(64, 16);
this.Button1.Name = "Button1";
this.Button1.Size = new System.Drawing.Size(176, 23);
this.Button1.TabIndex = 0;
this.Button1.Text = "Click me for list sorted by length";
this.Button1.Click += new System.EventHandler(Button1_Click);
this.sortingBox.Items.AddRange(new object[]{"System",
"System.Windows.Forms", "System.Xml", "System.Net",
"System.Drawing", "System.IO"});
this.sortingBox.Location =
new System.Drawing.Point(72, 48);
this.sortingBox.Size =
new System.Drawing.Size(120, 95);
this.sortingBox.TabIndex = 1;
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.sortingBox);
this.Controls.Add(this.Button1);
this.Name = "Form1";
this.Text = "Sort Example";
this.ResumeLayout(false);
}
public static void Main()
{
Application.Run(new Form1());
}
private void Button1_Click(System.Object sender, System.EventArgs e)
{
// Set the Sorted property to True to raise the overridden Sort
// method.
sortingBox.Sorted = true;
}
}
// This class inherits from ListBox and implements a different
// sorting method. Sort will be called by setting the class's Sorted
// property to True.
public class SortByLengthListBox:
ListBox
{
public SortByLengthListBox() : base()
{
}
// Overrides the parent class Sort to perform a simple
// bubble sort on the length of the string contained in each item.
protected override void Sort()
{
if (Items.Count > 1)
{
bool swapped;
do
{
int counter = Items.Count - 1;
swapped = false;
while (counter > 0)
{
// Compare the items' length.
if (Items[counter].ToString().Length
< Items[counter-1].ToString().Length)
{
// Swap the items.
object temp = Items[counter];
Items[counter] = Items[counter-1];
Items[counter-1] = temp;
swapped = true;
}
// Decrement the counter.
counter -= 1;
}
}
while((swapped==true));
}
}
}
Imports System.Drawing
Imports System.Windows.Forms
Public Class Form1
Inherits System.Windows.Forms.Form
Public Sub New()
MyBase.New()
Me.Button1 = New System.Windows.Forms.Button
Me.SortByLengthListBox1 = New SortByLengthListBox
Me.SuspendLayout()
Me.Button1.Location = New System.Drawing.Point(64, 16)
Me.Button1.Name = "Button1"
Me.Button1.Size = New System.Drawing.Size(176, 23)
Me.Button1.TabIndex = 0
Me.Button1.Text = "Click me for list sorted by length"
Me.SortByLengthListBox1.Items.AddRange(New Object() {"System", _
"System.Windows.Forms", "System.Xml", _
"System.Net", "System.Drawing", "System.IO"})
Me.SortByLengthListBox1.Location = New System.Drawing.Point(72, 48)
Me.SortByLengthListBox1.Name = "SortByLengthListBox1"
Me.SortByLengthListBox1.Size = New System.Drawing.Size(120, 95)
Me.SortByLengthListBox1.TabIndex = 1
Me.ClientSize = New System.Drawing.Size(292, 266)
Me.Controls.Add(Me.SortByLengthListBox1)
Me.Controls.Add(Me.Button1)
Me.Name = "Form1"
Me.Text = "Sort Example"
Me.ResumeLayout(False)
End Sub
Friend WithEvents Button1 As System.Windows.Forms.Button
Friend WithEvents SortByLengthListBox1 As SortByLengthListBox
Public Shared Sub Main()
Application.Run(New Form1)
End Sub
Private Sub Button1_Click(ByVal sender As System.Object, _
ByVal e As System.EventArgs) Handles Button1.Click
' Set the Sorted property to True to raise the overridden Sort
' method.
SortByLengthListBox1.Sorted = True
End Sub
End Class
' This class inherits from ListBox and implements a different
' sorting method. Sort will be called by setting the class's Sorted
' property to True.
Public Class SortByLengthListBox
Inherits ListBox
Public Sub New()
MyBase.New()
End Sub
' Overrides the parent class Sort to perform a simple
' bubble sort on the length of the string contained in each item.
Protected Overrides Sub Sort()
If (Items.Count > 1) Then
Dim swapped As Boolean
Do
Dim counter As Integer = Items.Count - 1
swapped = False
While (counter > 0)
' Compare the items' length.
If Items(counter).ToString.Length < _
Items(counter - 1).ToString.Length Then
' If true, swap the items.
Dim temp As Object = Items(counter)
Items(counter) = Items(counter - 1)
Items(counter - 1) = temp
swapped = True
End If
' Decrement the counter.
counter -= 1
End While
Loop While (swapped = True)
End If
End Sub
End Class
Hinweise
Sort erzwingt die Auflistung, jedes Element wieder zu sich selbst hinzuzufügen, wenn die Sorted Eigenschaft ist true. Jedes Element wird dann an die richtige Position eingefügt.
Hinweise für Vererber
Sie können diese Methode in Ihrer abgeleiteten Klasse außer Kraft setzen, um Ihre eigene Sortierroutine bereitzustellen. Greifen Sie auf die Ergebnisse der überschriebenen Sort() Methode zu, indem Sie die Sorted Eigenschaft auf truefestlegen. Beim Hinzufügen von Elementen zu einem ListBox, ist es effizienter, die Elemente zuerst zu sortieren und dann neue Elemente hinzuzufügen.