ComboBox クラス
Windows コンボ ボックス コントロールを表します。
この型のすべてのメンバの一覧については、ComboBox メンバ を参照してください。
System.Object
System.MarshalByRefObject
System.ComponentModel.Component
System.Windows.Forms.Control
System.Windows.Forms.ListControl
System.Windows.Forms.ComboBox
Public Class ComboBox
Inherits ListControl
[C#]
public class ComboBox : ListControl
[C++]
public __gc class ComboBox : public ListControl
[JScript]
public class ComboBox extends ListControl
スレッドセーフ
この型の public static (Visual Basicでは Shared) のすべてのメンバは、マルチスレッド操作で安全に使用できます。インスタンスのメンバの場合は、スレッドセーフであるとは限りません。
解説
ComboBox には、 ListBox と編集フィールドが組み合わされて表示され、ユーザーはリストで選択したり、新しくテキストを入力したりできます。 ComboBox の既定の動作は、非表示のドロップダウン リストが付いた編集フィールドを表示します。 DropDownStyle プロパティは、表示するコンボ ボックスのスタイルを決定します。値を入力して、単純なドロップダウン (リストが常に表示される)、ドロップダウン リスト ボックス (テキスト部分が編集できず、リストを表示するには矢印をクリックする必要がある)、または既定のドロップダウン リスト ボックス (テキスト部分が編集でき、ユーザーがリストを表示するには方向キーを押す必要がある) を設定できます。ユーザーが編集できないリストを常に表示するには、 ListBox コントロールを使用します。
実行時に、リストにオブジェクトを追加するには、 AddRange メソッドを使用してオブジェクト参照の配列を割り当てます。各オブジェクトの既定の文字列値がリストに表示されます。 Add メソッドを使用して、個別のオブジェクトを追加できます。
表示機能および選択機能の他に、 ComboBox には、 ComboBox に項目を効率よく追加したり、リストの項目にあるテキストを検索したりできる機能も用意されています。 BeginUpdate メソッドおよび EndUpdate メソッドを使用すると、リストに項目を追加するたびにコントロールを再描画せずに ComboBox に多数の項目を追加できます。 FindString メソッドおよび FindStringExact メソッドを使用すると、特定の検索文字列を含むリスト内の項目を検索できます。
リストで現在選択されている項目を管理するには、編集フィールドに表示された文字列を指定する Text プロパティ、選択されている項目を取得または設定する SelectedIndex プロパティ、およびオブジェクトへの参照を取得または設定する SelectedItem プロパティを使用します。
使用例
[Visual Basic, C#, C++] ComboBox に項目を追加する Add メソッド、 ComboBox 内の項目を検索する FindString メソッド、および ComboBox に多数の項目を効率よく追加する BeginUpdate メソッドと EndUpdate メソッドの使い方を示す、アプリケーション全体の例を次に示します。
Imports System
Imports System.Windows.Forms
Namespace ComboBoxSampleNamespace
Public Class ComboBoxSample
Inherits System.Windows.Forms.Form
Private addButton As System.Windows.Forms.Button
Private textBox2 As System.Windows.Forms.TextBox
Private addGrandButton As System.Windows.Forms.Button
Private comboBox1 As System.Windows.Forms.ComboBox
Private showSelectedButton As System.Windows.Forms.Button
Private textBox1 As System.Windows.Forms.TextBox
Private findButton As System.Windows.Forms.Button
Private label1 As System.Windows.Forms.Label
Public Sub New()
MyBase.New()
Me.InitializeComponent()
End Sub
<System.STAThreadAttribute()> Public Shared Sub Main()
System.Windows.Forms.Application.Run(New ComboBoxSample())
End Sub
Private Sub InitializeComponent()
Me.addButton = New System.Windows.Forms.Button()
Me.textBox2 = New System.Windows.Forms.TextBox()
Me.addGrandButton = New System.Windows.Forms.Button()
Me.comboBox1 = New System.Windows.Forms.ComboBox()
Me.showSelectedButton = New System.Windows.Forms.Button()
Me.textBox1 = New System.Windows.Forms.TextBox()
Me.findButton = New System.Windows.Forms.Button()
Me.label1 = New System.Windows.Forms.Label()
Me.addButton.Location = New System.Drawing.Point(248, 32)
Me.addButton.Size = New System.Drawing.Size(40, 24)
Me.addButton.TabIndex = 1
Me.addButton.Text = "Add"
AddHandler Me.addButton.Click, AddressOf Me.addButton_Click
Me.textBox2.Location = New System.Drawing.Point(8, 64)
Me.textBox2.Size = New System.Drawing.Size(232, 20)
Me.textBox2.TabIndex = 6
Me.textBox2.Text = ""
Me.addGrandButton.Location = New System.Drawing.Point(8, 96)
Me.addGrandButton.Size = New System.Drawing.Size(280, 23)
Me.addGrandButton.TabIndex = 2
Me.addGrandButton.Text = "Add 1,000 Items"
AddHandler Me.addGrandButton.Click, AddressOf Me.addGrandButton_Click
Me.comboBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Bottom Or System.Windows.Forms.AnchorStyles.Left) _
Or System.Windows.Forms.AnchorStyles.Right)
Me.comboBox1.DropDownWidth = 280
Me.comboBox1.Items.AddRange(New Object() {"Item 1", "Item 2", "Item 3", "Item 4", "Item 5"})
Me.comboBox1.Location = New System.Drawing.Point(8, 248)
Me.comboBox1.Size = New System.Drawing.Size(280, 21)
Me.comboBox1.TabIndex = 7
Me.showSelectedButton.Location = New System.Drawing.Point(8, 128)
Me.showSelectedButton.Size = New System.Drawing.Size(280, 24)
Me.showSelectedButton.TabIndex = 4
Me.showSelectedButton.Text = "What Item is Selected?"
AddHandler Me.showSelectedButton.Click, AddressOf Me.showSelectedButton_Click
Me.textBox1.Location = New System.Drawing.Point(8, 32)
Me.textBox1.Size = New System.Drawing.Size(232, 20)
Me.textBox1.TabIndex = 5
Me.textBox1.Text = ""
Me.findButton.Location = New System.Drawing.Point(248, 64)
Me.findButton.Size = New System.Drawing.Size(40, 24)
Me.findButton.TabIndex = 3
Me.findButton.Text = "Find"
AddHandler Me.findButton.Click, AddressOf Me.findButton_Click
Me.label1.Location = New System.Drawing.Point(8, 224)
Me.label1.Size = New System.Drawing.Size(144, 23)
Me.label1.TabIndex = 0
Me.label1.Text = "Test ComboBox"
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(292, 273)
Me.Controls.AddRange(New System.Windows.Forms.Control() {Me.comboBox1, Me.textBox2, Me.textBox1, Me.showSelectedButton, Me.findButton, Me.addGrandButton, Me.addButton, Me.label1})
Me.Text = "ComboBox Sample"
End Sub
Private Sub addButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
comboBox1.Items.Add(textBox1.Text)
End Sub
Private Sub findButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim index As Integer
index = comboBox1.FindString(textBox2.Text)
comboBox1.SelectedIndex = index
End Sub
Private Sub addGrandButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
comboBox1.BeginUpdate()
Dim I As Integer
For I = 0 To 1000
comboBox1.Items.Add("Item 1" + i.ToString())
Next
comboBox1.EndUpdate()
End Sub
Private Sub showSelectedButton_Click(ByVal sender As Object, ByVal e As System.EventArgs)
Dim selectedIndex As Integer
selectedIndex = comboBox1.SelectedIndex
Dim selectedItem As Object
selectedItem = comboBox1.SelectedItem
MessageBox.Show("Selected Item Text: " & selectedItem.ToString() & Microsoft.VisualBasic.Constants.vbCrLf & _
"Index: " & selectedIndex.ToString())
End Sub
End Class
End Namespace
[C#]
using System;
using System.Windows.Forms;
namespace Win32Form1Namespace {
public class Win32Form1 : System.Windows.Forms.Form {
private System.Windows.Forms.Button addButton;
private System.Windows.Forms.TextBox textBox2;
private System.Windows.Forms.Button addGrandButton;
private System.Windows.Forms.ComboBox comboBox1;
private System.Windows.Forms.Button showSelectedButton;
private System.Windows.Forms.TextBox textBox1;
private System.Windows.Forms.Button findButton;
private System.Windows.Forms.Label label1;
public Win32Form1() {
this.InitializeComponent();
}
[System.STAThreadAttribute()]
public static void Main() {
System.Windows.Forms.Application.Run(new Win32Form1());
}
private void InitializeComponent() {
this.addButton = new System.Windows.Forms.Button();
this.textBox2 = new System.Windows.Forms.TextBox();
this.addGrandButton = new System.Windows.Forms.Button();
this.comboBox1 = new System.Windows.Forms.ComboBox();
this.showSelectedButton = new System.Windows.Forms.Button();
this.textBox1 = new System.Windows.Forms.TextBox();
this.findButton = new System.Windows.Forms.Button();
this.label1 = new System.Windows.Forms.Label();
this.addButton.Location = new System.Drawing.Point(248, 32);
this.addButton.Size = new System.Drawing.Size(40, 24);
this.addButton.TabIndex = 1;
this.addButton.Text = "Add";
this.addButton.Click += new System.EventHandler(this.addButton_Click);
this.textBox2.Location = new System.Drawing.Point(8, 64);
this.textBox2.Size = new System.Drawing.Size(232, 20);
this.textBox2.TabIndex = 6;
this.textBox2.Text = "";
this.addGrandButton.Location = new System.Drawing.Point(8, 96);
this.addGrandButton.Size = new System.Drawing.Size(280, 23);
this.addGrandButton.TabIndex = 2;
this.addGrandButton.Text = "Add 1,000 Items";
this.addGrandButton.Click += new System.EventHandler(this.addGrandButton_Click);
this.comboBox1.Anchor = ((System.Windows.Forms.AnchorStyles.Bottom | System.Windows.Forms.AnchorStyles.Left)
| System.Windows.Forms.AnchorStyles.Right);
this.comboBox1.DropDownWidth = 280;
this.comboBox1.Items.AddRange(new object[] {"Item 1",
"Item 2",
"Item 3",
"Item 4",
"Item 5"});
this.comboBox1.Location = new System.Drawing.Point(8, 248);
this.comboBox1.Size = new System.Drawing.Size(280, 21);
this.comboBox1.TabIndex = 7;
this.showSelectedButton.Location = new System.Drawing.Point(8, 128);
this.showSelectedButton.Size = new System.Drawing.Size(280, 24);
this.showSelectedButton.TabIndex = 4;
this.showSelectedButton.Text = "What Item is Selected?";
this.showSelectedButton.Click += new System.EventHandler(this.showSelectedButton_Click);
this.textBox1.Location = new System.Drawing.Point(8, 32);
this.textBox1.Size = new System.Drawing.Size(232, 20);
this.textBox1.TabIndex = 5;
this.textBox1.Text = "";
this.findButton.Location = new System.Drawing.Point(248, 64);
this.findButton.Size = new System.Drawing.Size(40, 24);
this.findButton.TabIndex = 3;
this.findButton.Text = "Find";
this.findButton.Click += new System.EventHandler(this.findButton_Click);
this.label1.Location = new System.Drawing.Point(8, 224);
this.label1.Size = new System.Drawing.Size(144, 23);
this.label1.TabIndex = 0;
this.label1.Text = "Test ComboBox";
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 273);
this.Controls.AddRange(new System.Windows.Forms.Control[] {this.comboBox1,
this.textBox2,
this.textBox1,
this.showSelectedButton,
this.findButton,
this.addGrandButton,
this.addButton,
this.label1});
this.Text = "ComboBox Sample";
}
private void addButton_Click(object sender, System.EventArgs e) {
comboBox1.Items.Add(textBox1.Text);
}
private void addGrandButton_Click(object sender, System.EventArgs e) {
comboBox1.BeginUpdate();
for (int i = 0; i < 1000; i++) {
comboBox1.Items.Add("Item 1" + i.ToString());
}
comboBox1.EndUpdate();
}
private void findButton_Click(object sender, System.EventArgs e) {
int index = comboBox1.FindString(textBox2.Text);
comboBox1.SelectedIndex = index;
}
private void showSelectedButton_Click(object sender, System.EventArgs e) {
int selectedIndex = comboBox1.SelectedIndex;
Object selectedItem = comboBox1.SelectedItem;
MessageBox.Show("Selected Item Text: " + selectedItem.ToString() + "\n" +
"Index: " + selectedIndex.ToString());
}
}
}
[C++]
using namespace System;
using namespace System::Windows::Forms;
namespace Win32Form1Namespace {
public __gc class Win32Form1 : public System::Windows::Forms::Form {
private:
System::Windows::Forms::Button* addButton;
System::Windows::Forms::TextBox* textBox2;
System::Windows::Forms::Button* addGrandButton;
System::Windows::Forms::ComboBox* comboBox1;
System::Windows::Forms::Button* showSelectedButton;
System::Windows::Forms::TextBox* textBox1;
System::Windows::Forms::Button* findButton;
System::Windows::Forms::Label* label1;
public:
Win32Form1() {
this->InitializeComponent();
}
private:
void InitializeComponent() {
this->addButton = new System::Windows::Forms::Button();
this->textBox2 = new System::Windows::Forms::TextBox();
this->addGrandButton = new System::Windows::Forms::Button();
this->comboBox1 = new System::Windows::Forms::ComboBox();
this->showSelectedButton = new System::Windows::Forms::Button();
this->textBox1 = new System::Windows::Forms::TextBox();
this->findButton = new System::Windows::Forms::Button();
this->label1 = new System::Windows::Forms::Label();
this->addButton->Location = System::Drawing::Point(248, 32);
this->addButton->Size = System::Drawing::Size(40, 24);
this->addButton->TabIndex = 1;
this->addButton->Text = S"Add";
this->addButton->Click += new System::EventHandler(this, &Win32Form1::addButton_Click);
this->textBox2->Location = System::Drawing::Point(8, 64);
this->textBox2->Size = System::Drawing::Size(232, 20);
this->textBox2->TabIndex = 6;
this->textBox2->Text = S"";
this->addGrandButton->Location = System::Drawing::Point(8, 96);
this->addGrandButton->Size = System::Drawing::Size(280, 23);
this->addGrandButton->TabIndex = 2;
this->addGrandButton->Text = S"Add 1, 000 Items";
this->addGrandButton->Click += new System::EventHandler(this, &Win32Form1::addGrandButton_Click);
this->comboBox1->Anchor = static_cast<System::Windows::Forms::AnchorStyles>(
(System::Windows::Forms::AnchorStyles::Bottom | System::Windows::Forms::AnchorStyles::Left)
| System::Windows::Forms::AnchorStyles::Right);
this->comboBox1->DropDownWidth = 280;
Object* objectArray[] = {S"Item 1",
S"Item 2",
S"Item 3",
S"Item 4",
S"Item 5"};
this->comboBox1->Items->AddRange(objectArray);
this->comboBox1->Location = System::Drawing::Point(8, 248);
this->comboBox1->Size = System::Drawing::Size(280, 21);
this->comboBox1->TabIndex = 7;
this->showSelectedButton->Location = System::Drawing::Point(8, 128);
this->showSelectedButton->Size = System::Drawing::Size(280, 24);
this->showSelectedButton->TabIndex = 4;
this->showSelectedButton->Text = S"What Item is Selected?";
this->showSelectedButton->Click += new System::EventHandler(this, &Win32Form1::showSelectedButton_Click);
this->textBox1->Location = System::Drawing::Point(8, 32);
this->textBox1->Size = System::Drawing::Size(232, 20);
this->textBox1->TabIndex = 5;
this->textBox1->Text = S"";
this->findButton->Location = System::Drawing::Point(248, 64);
this->findButton->Size = System::Drawing::Size(40, 24);
this->findButton->TabIndex = 3;
this->findButton->Text = S"Find";
this->findButton->Click += new System::EventHandler(this, &Win32Form1::findButton_Click);
this->label1->Location = System::Drawing::Point(8, 224);
this->label1->Size = System::Drawing::Size(144, 23);
this->label1->TabIndex = 0;
this->label1->Text = S"Test ComboBox";
this->AutoScaleBaseSize = System::Drawing::Size(5, 13);
this->ClientSize = System::Drawing::Size(292, 273);
System::Windows::Forms::Control* controlsArray[] = {this->comboBox1,
this->textBox2,
this->textBox1,
this->showSelectedButton,
this->findButton,
this->addGrandButton,
this->addButton,
this->label1};
this->Controls->AddRange(controlsArray);
this->Text = S"ComboBox Sample";
}
void addButton_Click(Object* /*sender*/, System::EventArgs* /*e*/) {
comboBox1->Items->Add(textBox1->Text);
}
void addGrandButton_Click(Object* /*sender*/, System::EventArgs* /*e*/) {
comboBox1->BeginUpdate();
for (int i = 0; i < 1000; i++) {
comboBox1->Items->Add(String::Concat(S"Item 1 ", i.ToString()));
}
comboBox1->EndUpdate();
}
void findButton_Click(Object* /*sender*/, System::EventArgs* /*e*/) {
int index = comboBox1->FindString(textBox2->Text);
comboBox1->SelectedIndex = index;
}
void showSelectedButton_Click(Object* /*sender*/, System::EventArgs* /*e*/) {
int selectedIndex = comboBox1->SelectedIndex;
Object* selectedItem = comboBox1->SelectedItem;
MessageBox::Show(String::Concat(S"Selected Item Text: ", selectedItem->ToString(),
S"\n Index: ", selectedIndex.ToString()));
}
};
}
[System::STAThreadAttribute]
int main() {
System::Windows::Forms::Application::Run(new Win32Form1Namespace::Win32Form1());
}
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をクリックします。
必要条件
名前空間: System.Windows.Forms
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ, .NET Compact Framework - Windows CE .NET
アセンブリ: System.Windows.Forms (System.Windows.Forms.dll 内)