Form.HelpButton 属性
重要
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获取或设置一个值，该值指示是否应在窗体的标题框中显示“帮助”按钮。
public:
property bool HelpButton { bool get(); void set(bool value); };C#
public bool HelpButton { get; set; }member this.HelpButton : bool with get, setPublic Property HelpButton As Boolean如果为 true，则在窗体的标题栏中显示“帮助”按钮；否则，为 false。 默认值为 false。
以下示例创建 的新实例 Form ，并调用 ShowDialog 方法将窗体显示为对话框。 该示例设置 FormBorderStyle、 AcceptButton、 CancelButton、 MinimizeBox、 MaximizeBox和 StartPosition 属性，以将窗体的外观和功能更改为对话框。 该示例还使用 Add 窗体集合的 Controls 方法添加两个 Button 控件。 该示例使用 HelpButton 属性在对话框的描述文字栏中显示“帮助”按钮。
public:
void CreateMyForm()
{
// Create a new instance of the form.
Form^ form1 = gcnew Form;
// Create two buttons to use as the accept and cancel buttons.
Button^ button1 = gcnew Button;
Button^ button2 = gcnew Button;
// Set the text of button1 to "OK".
button1->Text = "OK";
// Set the position of the button on the form.
button1->Location = Point(10,10);
// Set the text of button2 to "Cancel".
button2->Text = "Cancel";
// Set the position of the button based on the location of button1.
button2->Location =
Point( button1->Left, button1->Height + button1->Top + 10 );
// Set the caption bar text of the form.
form1->Text = "My Dialog Box";
// Display a help button on the form.
form1->HelpButton = true;
// Define the border style of the form to a dialog box.
form1->FormBorderStyle = ::FormBorderStyle::FixedDialog;
// Set the MaximizeBox to false to remove the maximize box.
form1->MaximizeBox = false;
// Set the MinimizeBox to false to remove the minimize box.
form1->MinimizeBox = false;
// Set the accept button of the form to button1.
form1->AcceptButton = button1;
// Set the cancel button of the form to button2.
form1->CancelButton = button2;
// Set the start position of the form to the center of the screen.
form1->StartPosition = FormStartPosition::CenterScreen;
// Add button1 to the form.
form1->Controls->Add( button1 );
// Add button2 to the form.
form1->Controls->Add( button2 );
// Display the form as a modal dialog box.
form1->ShowDialog();
}
C#
public void CreateMyForm()
{
// Create a new instance of the form.
Form form1 = new Form();
// Create two buttons to use as the accept and cancel buttons.
Button button1 = new Button ();
Button button2 = new Button ();
// Set the text of button1 to "OK".
button1.Text = "OK";
// Set the position of the button on the form.
button1.Location = new Point (10, 10);
// Set the text of button2 to "Cancel".
button2.Text = "Cancel";
// Set the position of the button based on the location of button1.
button2.Location
= new Point (button1.Left, button1.Height + button1.Top + 10);
// Set the caption bar text of the form.
form1.Text = "My Dialog Box";
// Display a help button on the form.
form1.HelpButton = true;
// Define the border style of the form to a dialog box.
form1.FormBorderStyle = FormBorderStyle.FixedDialog;
// Set the MaximizeBox to false to remove the maximize box.
form1.MaximizeBox = false;
// Set the MinimizeBox to false to remove the minimize box.
form1.MinimizeBox = false;
// Set the accept button of the form to button1.
form1.AcceptButton = button1;
// Set the cancel button of the form to button2.
form1.CancelButton = button2;
// Set the start position of the form to the center of the screen.
form1.StartPosition = FormStartPosition.CenterScreen;
// Add button1 to the form.
form1.Controls.Add(button1);
// Add button2 to the form.
form1.Controls.Add(button2);
// Display the form as a modal dialog box.
form1.ShowDialog();
}
Public Sub CreateMyForm()
' Create a new instance of the form.
Dim form1 As New Form()
' Create two buttons to use as the accept and cancel buttons.
Dim button1 As New Button()
Dim button2 As New Button()
' Set the text of button1 to "OK".
button1.Text = "OK"
' Set the position of the button on the form.
button1.Location = New Point(10, 10)
' Set the text of button2 to "Cancel".
button2.Text = "Cancel"
' Set the position of the button based on the location of button1.
button2.Location = _
New Point(button1.Left, button1.Height + button1.Top + 10)
' Set the caption bar text of the form.
form1.Text = "My Dialog Box"
' Display a help button on the form.
form1.HelpButton = True
' Define the border style of the form to a dialog box.
form1.FormBorderStyle = FormBorderStyle.FixedDialog
' Set the MaximizeBox to false to remove the maximize box.
form1.MaximizeBox = False
' Set the MinimizeBox to false to remove the minimize box.
form1.MinimizeBox = False
' Set the accept button of the form to button1.
form1.AcceptButton = button1
' Set the cancel button of the form to button2.
form1.CancelButton = button2
' Set the start position of the form to the center of the screen.
form1.StartPosition = FormStartPosition.CenterScreen
' Add button1 to the form.
form1.Controls.Add(button1)
' Add button2 to the form.
form1.Controls.Add(button2)
' Display the form as a modal dialog box.
form1.ShowDialog()
End Sub
当此属性设置为 true时，“关闭”按钮左侧的描述文字栏中会显示一个带有问号的小按钮。 可以使用此按钮显示应用程序的帮助。 可以为 事件创建事件处理程序， HelpRequested 以便在单击窗体的“帮助”按钮时向用户显示帮助信息。
若要显示“帮助”按钮，窗体 ControlBox 属性的值必须是 true其默认值。 属性ControlBox确定描述文字栏的右上角是否包含诸如最大化按钮、最小化按钮、帮助按钮和关闭按钮等控件。 此外，还必须将窗体的 FormBorderStyle 属性设置为 FormBorderStyle.FixedSingle、 FormBorderStyle.Sizable、 FormBorderStyle.Fixed3D或 FormBorderStyle.FixedDialog。
重要
如果显示“最大化”HelpButton或“最小化”按钮，则忽略 属性的值。
| 产品 | 版本 |
|---|---|
| .NET Framework | 1.1, 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1 |
| Windows Desktop | 3.0, 3.1, 5, 6, 7, 8, 9, 10 |
