ListBox.Sort Metode
Definisi
Penting
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Mengurutkan item dalam ListBox.
protected:
virtual void Sort();protected virtual void Sort();abstract member Sort : unit -> unit
override this.Sort : unit -> unitProtected Overridable Sub Sort ()Contoh
Contoh kode berikut menunjukkan menggunakan Sort metode . Contoh menunjukkan pewarisan dari ListBox kelas dan mengambil alih Sort metode di kelas turunan untuk melakukan pengurutan yang ditentukan pengguna. Untuk menjalankan contoh ini tempelkan kode berikut dalam formulir kosong.
// 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 );
}
}
};
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);
}
}
}
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
Keterangan
Sort memaksa koleksi untuk menambahkan setiap item kembali ke dirinya sendiri jika Sorted properti adalah true. Setiap item kemudian disisipkan ke posisi yang benar.
Catatan Bagi Inheritor
Anda dapat mengambil alih metode ini di kelas turunan Anda untuk menyediakan rutinitas pengurutan Anda sendiri. Akses hasil metode yang ditimpa Sort() dengan mengatur Sorted properti ke true. Saat menambahkan item ke ListBox, lebih efisien untuk mengurutkan item terlebih dahulu lalu menambahkan item baru.
