HelpProvider.GetHelpString メソッド
指定したコントロールのポップアップ ヘルプ ウィンドウの内容を取得します。
Public Overridable Function GetHelpString( _
ByVal ctl As Control _) As String
[C#]
public virtual string GetHelpString(Controlctl);
[C++]
public: virtual String* GetHelpString(Control* ctl);
[JScript]
public function GetHelpString(
ctl : Control) : String;
パラメータ
- ctl
ヘルプ文字列の取得対象となる Control 。
戻り値
このコントロールに関連付けられたヘルプ文字列。既定値は null 参照 (Visual Basic では Nothing) です。
解説
実行時にこのヘルプ文字列を表示するには、指定したコントロールに入力フォーカスがあるときに、ユーザーは F1 キーを押します。
使用例
[Visual Basic, C#] KeyPressEventHandler クラスと KeyEventHandler クラスを使用して入力をフィルタするコード例を次に示します。また、この例では、 GetHelpString メソッドも使用しています。これは完成された例であるため、プロジェクトに追加すると実行できます。
Imports System.Drawing
Imports System.Windows.Forms
Imports System
Imports Microsoft.VisualBasic
Public Class Form1
Inherits System.Windows.Forms.Form
Public Sub New()
MyBase.New()
InitializeComponent()
AddHandlers()
InitializeFormHelp()
End Sub
Friend WithEvents Label1 As System.Windows.Forms.Label
Friend WithEvents Label2 As System.Windows.Forms.Label
Friend WithEvents Label3 As System.Windows.Forms.Label
Friend WithEvents withdrawal As System.Windows.Forms.TextBox
Friend WithEvents deposit As System.Windows.Forms.TextBox
Friend WithEvents ErrorProvider1 As System.Windows.Forms.ErrorProvider
Friend WithEvents balance As System.Windows.Forms.Label
Friend WithEvents HelpProvider1 As System.Windows.Forms.HelpProvider
<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
Me.withdrawal = New System.Windows.Forms.TextBox
Me.deposit = New System.Windows.Forms.TextBox
Me.Label1 = New System.Windows.Forms.Label
Me.Label2 = New System.Windows.Forms.Label
Me.Label3 = New System.Windows.Forms.Label
Me.ErrorProvider1 = New System.Windows.Forms.ErrorProvider
Me.balance = New System.Windows.Forms.Label
Me.HelpProvider1 = New System.Windows.Forms.HelpProvider
Me.SuspendLayout()
Me.withdrawal.Location = New System.Drawing.Point(32, 200)
Me.withdrawal.Name = "withdrawal"
Me.withdrawal.Size = New System.Drawing.Size(88, 20)
Me.withdrawal.TabIndex = 0
Me.withdrawal.Text = ""
Me.deposit.Location = New System.Drawing.Point(168, 200)
Me.deposit.Name = "deposit"
Me.deposit.TabIndex = 1
Me.deposit.Text = ""
Me.Label1.Location = New System.Drawing.Point(56, 88)
Me.Label1.Name = "Label1"
Me.Label1.Size = New System.Drawing.Size(96, 24)
Me.Label1.TabIndex = 2
Me.Label1.Text = "Account Balance:"
Me.Label2.Location = New System.Drawing.Point(168, 168)
Me.Label2.Name = "Label2"
Me.Label2.Size = New System.Drawing.Size(96, 24)
Me.Label2.TabIndex = 4
Me.Label2.Text = "Deposit:"
Me.Label3.Location = New System.Drawing.Point(32, 168)
Me.Label3.Name = "Label3"
Me.Label3.Size = New System.Drawing.Size(96, 24)
Me.Label3.TabIndex = 5
Me.Label3.Text = "Withdrawal:"
Me.ErrorProvider1.ContainerControl = Me
Me.balance.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D
Me.balance.Location = New System.Drawing.Point(152, 88)
Me.balance.Name = "balance"
Me.balance.TabIndex = 6
Me.balance.Text = "345.65"
Me.balance.TextAlign = System.Drawing.ContentAlignment.MiddleLeft
Me.AutoScaleBaseSize = New System.Drawing.Size(5, 13)
Me.ClientSize = New System.Drawing.Size(292, 266)
Me.Controls.Add(Me.balance)
Me.Controls.Add(Me.Label3)
Me.Controls.Add(Me.Label2)
Me.Controls.Add(Me.Label1)
Me.Controls.Add(Me.deposit)
Me.Controls.Add(Me.withdrawal)
Me.Name = "Form1"
Me.Text = "Form1"
Me.ResumeLayout(False)
End Sub
Private Sub AddHandlers()
'Add the event-handler delegates to handle the KeyDown events.
AddHandler deposit.KeyDown, _
New KeyEventHandler(AddressOf ProcessEntry)
AddHandler withdrawal.KeyDown, _
New KeyEventHandler(AddressOf ProcessEntry)
'Add the event-handler delegates to handled the KeyPress events.
AddHandler deposit.KeyPress, _
New KeyPressEventHandler(AddressOf CheckForDigits)
AddHandler withdrawal.KeyPress, _
New KeyPressEventHandler(AddressOf CheckForDigits)
End Sub
Private Sub InitializeFormHelp()
' Set the form's border to the FixedDialog style.
Me.FormBorderStyle = FormBorderStyle.FixedDialog
' Remove the Maximize and Minimize buttons from the form.
Me.MaximizeBox = False
Me.MinimizeBox = False
' Add the Help button to the form.
Me.HelpButton = True
' Set the Help string for the deposit textBox.
HelpProvider1.SetHelpString(deposit, _
"Enter an amount in the format xxx.xx" _
& "and press Enter to deposit.")
' Set the Help string for the withdrawal textBox.
HelpProvider1.SetHelpString(withdrawal, _
"Enter an amount in the format xxx.xx" _
& "and press Enter to withdraw.")
End Sub
Protected Sub ProcessEntry(ByVal sender As Object, _
ByVal e As KeyEventArgs)
' Cast the sender back to a TextBox.
Dim textBoxSender As Control = CType(sender, TextBox)
' Set the error description to an empty string ().
ErrorProvider1.SetError(textBoxSender, "")
' Declare the variable to hold the new balance.
Dim newBalance As Double
' Wrap the code in a Try/Catch block to catch
' errors that can occur when converting the string
' to a double.
Try
If (e.KeyCode = Keys.Enter) Then
' Switch on the text box that received
' the KeyPress event. Convert the text to type double,
' and compute the new balance.
Select Case textBoxSender.Name
Case "withdrawal"
newBalance = Double.Parse(balance.Text) _
- Double.Parse(withdrawal.Text)
withdrawal.Text = ""
Case "deposit"
newBalance = Double.Parse(balance.Text) _
+ Double.Parse(deposit.Text)
deposit.Text = ""
End Select
' Check the value of new balance and set the
' Forecolor property accordingly.
If (newBalance < 0) Then
balance.ForeColor = Color.Red
Else
balance.ForeColor = Color.Black
End If
' Set the text of the balance text box
' to the newBalance value.
balance.Text = newBalance.ToString
End If
Catch ex As FormatException
' If a FormatException is thrown, set the
' error string to the HelpString message for
' the control.
ErrorProvider1.SetError(textBoxSender, _
HelpProvider1.GetHelpString(textBoxSender))
End Try
End Sub
Protected Sub CheckForDigits(ByVal sender As Object, ByVal e _
As KeyPressEventArgs)
' If the character is not a digit, period, or backspace then
' ignore it by setting the KeyPressEventArgs.Handled
' property to true.
If Not (Char.IsDigit(e.KeyChar) _
Or e.KeyChar = "." Or e.KeyChar = ChrW(Keys.Back)) Then
e.Handled = True
End If
End Sub
Public Shared Sub Main()
Application.Run(New Form1)
End Sub
End Class
[C#]
using System.Drawing;
using System.Windows.Forms;
using System;
using Microsoft.VisualBasic;
public class Form1:
System.Windows.Forms.Form
{
public Form1() : base()
{
InitializeComponent();
AddHandlers();
InitializeFormHelp();
}
internal System.Windows.Forms.Label Label1;
internal System.Windows.Forms.Label Label2;
internal System.Windows.Forms.Label Label3;
internal System.Windows.Forms.TextBox withdrawal;
internal System.Windows.Forms.TextBox deposit;
internal System.Windows.Forms.ErrorProvider ErrorProvider1;
internal System.Windows.Forms.Label balance;
internal System.Windows.Forms.HelpProvider HelpProvider1;
[System.Diagnostics.DebuggerStepThrough]
private void InitializeComponent()
{
this.withdrawal = new System.Windows.Forms.TextBox();
this.deposit = new System.Windows.Forms.TextBox();
this.Label1 = new System.Windows.Forms.Label();
this.Label2 = new System.Windows.Forms.Label();
this.Label3 = new System.Windows.Forms.Label();
this.ErrorProvider1 = new System.Windows.Forms.ErrorProvider();
this.balance = new System.Windows.Forms.Label();
this.HelpProvider1 = new System.Windows.Forms.HelpProvider();
this.SuspendLayout();
this.withdrawal.Location = new System.Drawing.Point(32, 200);
this.withdrawal.Name = "withdrawal";
this.withdrawal.Size = new System.Drawing.Size(88, 20);
this.withdrawal.TabIndex = 0;
this.withdrawal.Text = "";
this.deposit.Location = new System.Drawing.Point(168, 200);
this.deposit.Name = "deposit";
this.deposit.TabIndex = 1;
this.deposit.Text = "";
this.Label1.Location = new System.Drawing.Point(56, 88);
this.Label1.Name = "Label1";
this.Label1.Size = new System.Drawing.Size(96, 24);
this.Label1.TabIndex = 2;
this.Label1.Text = "Account Balance:";
this.Label2.Location = new System.Drawing.Point(168, 168);
this.Label2.Name = "Label2";
this.Label2.Size = new System.Drawing.Size(96, 24);
this.Label2.TabIndex = 4;
this.Label2.Text = "Deposit:";
this.Label3.Location = new System.Drawing.Point(32, 168);
this.Label3.Name = "Label3";
this.Label3.Size = new System.Drawing.Size(96, 24);
this.Label3.TabIndex = 5;
this.Label3.Text = "Withdrawal:";
this.ErrorProvider1.ContainerControl = this;
this.balance.BorderStyle = System.Windows.Forms.BorderStyle.Fixed3D;
this.balance.Location = new System.Drawing.Point(152, 88);
this.balance.Name = "balance";
this.balance.TabIndex = 6;
this.balance.Text = "345.65";
this.balance.TextAlign = System.Drawing.ContentAlignment.MiddleLeft;
this.AutoScaleBaseSize = new System.Drawing.Size(5, 13);
this.ClientSize = new System.Drawing.Size(292, 266);
this.Controls.Add(this.balance);
this.Controls.Add(this.Label3);
this.Controls.Add(this.Label2);
this.Controls.Add(this.Label1);
this.Controls.Add(this.deposit);
this.Controls.Add(this.withdrawal);
this.Name = "Form1";
this.Text = "Form1";
this.ResumeLayout(false);
}
private void AddHandlers()
{
// Add the event-handler delegates to handled the KeyDown
// events.
deposit.KeyDown +=new KeyEventHandler(ProcessEntry);
withdrawal.KeyDown += new KeyEventHandler(ProcessEntry);
// Add the event-handler delegates to handled the KeyPress
// events.
deposit.KeyPress += new KeyPressEventHandler(CheckForDigits);
withdrawal.KeyPress +=
new KeyPressEventHandler(CheckForDigits);
}
private void InitializeFormHelp()
{
// Set the form's border to the FixedDialog style.
this.FormBorderStyle = FormBorderStyle.FixedDialog;
// Remove the Maximize and Minimize buttons from the form.
this.MaximizeBox = false;
this.MinimizeBox = false;
// Add the Help button to the form.
this.HelpButton = true;
// Set the Help string for the deposit textBox.
HelpProvider1.SetHelpString(deposit,
"Enter an amount in the format xxx.xx" +
"and press Enter to deposit.");
// Set the Help string for the withdrawal textBox.
HelpProvider1.SetHelpString(withdrawal,
"Enter an amount in the format xxx.xx" +
"and press Enter to withdraw.");
}
protected void ProcessEntry(object sender, KeyEventArgs e)
{
// Cast the sender back to a TextBox.
Control textBoxSender = (TextBox) sender;
// Set the error description to an empty string ().
ErrorProvider1.SetError(textBoxSender, "");
// Declare the variable to hold the new balance.
double newBalance = 0;
// Wrap the code in a Try/Catch block to catch
// errors that can occur when converting the string
// to a double.
try
{
if (e.KeyCode==Keys.Enter)
// Switch on the text box that received
// the KeyPress event. Convert the text to type double,
// and compute the new balance.
{
switch(textBoxSender.Name)
{
case "withdrawal":
newBalance = Double.Parse(balance.Text)
- Double.Parse(withdrawal.Text);
withdrawal.Text = "";
break;
case "deposit":
newBalance = Double.Parse(balance.Text)
+ Double.Parse(deposit.Text);
deposit.Text = "";
break;
}
// Check the value of new balance and set the
// Forecolor property accordingly.
if (newBalance < 0)
{
balance.ForeColor = Color.Red;
}
else
{
balance.ForeColor = Color.Black;
}
// Set the text of the balance text box
// to the newBalance value.
balance.Text = newBalance.ToString();
}
}
catch(FormatException)
{
// If a FormatException is thrown, set the
// error string to the HelpString message for
// the control.
ErrorProvider1.SetError(textBoxSender,
HelpProvider1.GetHelpString(textBoxSender));
}
}
protected void CheckForDigits(object sender, KeyPressEventArgs e)
{
// If the character is not a digit, period, or backspace then
// ignore it by setting the KeyPressEventArgs.Handled
// property to true.
if (!(Char.IsDigit(e.KeyChar) || e.KeyChar == '.' ||
e.KeyChar == (char)(Keys.Back)))
{
e.Handled = true;
}
}
public static void Main()
{
Application.Run(new Form1());
}
}
[C++, JScript] C++ および JScript のサンプルはありません。Visual Basic および C# のサンプルを表示するには、このページの左上隅にある言語のフィルタ ボタン .gif)
をクリックします。
必要条件
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
参照
HelpProvider クラス | HelpProvider メンバ | System.Windows.Forms 名前空間 | GetHelpString | GetHelpKeyword | GetShowHelp | SetHelpString | SetHelpKeyword