Control.Top 属性

获取或设置控件上边缘与其容器的工作区上边缘之间的距离（以像素为单位）。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Property Top As Integer
用法
Dim instance As Control
Dim value As Integer

value = instance.Top

instance.Top = value

public int Top { get; set; }

public:
property int Top {
    int get ();
    void set (int value);
}

/** @property */
public int get_Top ()

/** @property */
public void set_Top (int value)

public function get Top () : int

public function set Top (value : int)

属性值

Int32 表示控件下边缘与其容器的工作区上边缘之间的距离（以像素为单位）。

备注

Top 属性值等效于控件的 Location 属性值的 Point.Y 属性。

对 Height 和 Top 属性值所做的更改导致该控件的 Bottom 属性值更改。

示例

下面的代码示例在窗体中创建三个 Button 控件，并使用多种与大小相关的属性和与位置相关的属性来分别设置它们的大小和位置。此示例要求您的 Form 的宽度和高度至少为 300 像素。

' Create three buttons and place them on a form using 
' several size and location related properties. 
Private Sub AddOKCancelButtons()
   ' Set the button size and location using 
      ' the Size and Location properties. 
   Dim buttonOK As New Button()
   buttonOK.Location = New Point(136, 248)
   buttonOK.Size = New Size(75, 25)
   ' Set the Text property and make the 
   ' button the form's default button. 
   buttonOK.Text = "&OK"
   Me.AcceptButton = buttonOK
   
   ' Set the button size and location using the Top, 
   ' Left, Width, and Height properties. 
   Dim buttonCancel As New Button()
   buttonCancel.Top = buttonOK.Top
   buttonCancel.Left = buttonOK.Right + 5
   buttonCancel.Width = buttonOK.Width
   buttonCancel.Height = buttonOK.Height
   ' Set the Text property and make the 
   ' button the form's cancel button. 
   buttonCancel.Text = "&Cancel"
   Me.CancelButton = buttonCancel
   
   ' Set the button size and location using 
   ' the Bounds property. 
   Dim buttonHelp As New Button()
   buttonHelp.Bounds = New Rectangle(10, 10, 75, 25)
   ' Set the Text property of the button.
   buttonHelp.Text = "&Help"
   
   ' Add the buttons to the form.
   Me.Controls.AddRange(New Control() {buttonOK, buttonCancel, buttonHelp})
End Sub

// Create three buttons and place them on a form using 
// several size and location related properties. 
private void AddOKCancelButtons()
{
   // Set the button size and location using 
   // the Size and Location properties.
   Button buttonOK = new Button();
   buttonOK.Location = new Point(136,248);
   buttonOK.Size = new Size(75,25);
   // Set the Text property and make the 
   // button the form's default button. 
   buttonOK.Text = "&OK";
   this.AcceptButton = buttonOK;

   // Set the button size and location using the Top, 
   // Left, Width, and Height properties.
   Button buttonCancel = new Button();
   buttonCancel.Top = buttonOK.Top;
   buttonCancel.Left = buttonOK.Right + 5;
   buttonCancel.Width = buttonOK.Width;
   buttonCancel.Height = buttonOK.Height;
   // Set the Text property and make the 
   // button the form's cancel button.
   buttonCancel.Text = "&Cancel";
   this.CancelButton = buttonCancel;

   // Set the button size and location using 
   // the Bounds property.
   Button buttonHelp = new Button();
   buttonHelp.Bounds = new Rectangle(10,10, 75, 25);
   // Set the Text property of the button.
   buttonHelp.Text = "&Help";

   // Add the buttons to the form.
   this.Controls.AddRange(new Control[] {buttonOK, buttonCancel, buttonHelp} );
}

// Create three buttons and place them on a form using
// several size and location related properties.
void AddOKCancelButtons()
{
   
   // Set the button size and location using
   // the Size and Location properties.
   Button^ buttonOK = gcnew Button;
   buttonOK->Location = Point(136,248);
   buttonOK->Size = System::Drawing::Size( 75, 25 );
   
   // Set the Text property and make the
   // button the form's default button.
   buttonOK->Text = "&OK";
   this->AcceptButton = buttonOK;
   
   // Set the button size and location using the Top,
   // Left, Width, and Height properties.
   Button^ buttonCancel = gcnew Button;
   buttonCancel->Top = buttonOK->Top;
   buttonCancel->Left = buttonOK->Right + 5;
   buttonCancel->Width = buttonOK->Width;
   buttonCancel->Height = buttonOK->Height;
   
   // Set the Text property and make the
   // button the form's cancel button.
   buttonCancel->Text = "&Cancel";
   this->CancelButton = buttonCancel;
   
   // Set the button size and location using
   // the Bounds property.
   Button^ buttonHelp = gcnew Button;
   buttonHelp->Bounds = Rectangle(10,10,75,25);
   
   // Set the Text property of the button.
   buttonHelp->Text = "&Help";
   
   // Add the buttons to the form.
   array<Control^>^temp1 = {buttonOK,buttonCancel,buttonHelp};
   this->Controls->AddRange( temp1 );
}

// Create three buttons and place them on a form using 
// several size and location related properties. 
private void AddOKCancelButtons()
{
    // Set the button size and location using 
    // the Size and Location properties.
    Button buttonOK = new Button();
    buttonOK.set_Location(new Point(136, 248));
    buttonOK.set_Size(new Size(75, 25));
    // Set the Text property and make the 
    // button the form's default button. 
    buttonOK.set_Text("&OK");
    this.set_AcceptButton(buttonOK);
    // Set the button size and location using the Top, 
    // Left, Width, and Height properties.
    Button buttonCancel = new Button();
    buttonCancel.set_Top(buttonOK.get_Top());
    buttonCancel.set_Left(buttonOK.get_Right() + 5);
    buttonCancel.set_Width(buttonOK.get_Width());
    buttonCancel.set_Height(buttonOK.get_Height());
    // Set the Text property and make the 
    // button the form's cancel button.
    buttonCancel.set_Text("&Cancel");
    this.set_CancelButton(buttonCancel);
    // Set the button size and location using 
    // the Bounds property.
    Button buttonHelp = new Button();
    buttonHelp.set_Bounds(new Rectangle(10, 10, 75, 25));
    // Set the Text property of the button.
    buttonHelp.set_Text("&Help");
    // Add the buttons to the form.
    this.get_Controls().AddRange(new Control[] { buttonOK, buttonCancel,
        buttonHelp });
} //AddOKCancelButtons

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

.NET Compact Framework

受以下版本支持：2.0、1.0

请参见

参考

Control 类
Control 成员
System.Windows.Forms 命名空间
Point.Y
Control.Bottom 属性
Control.Bounds 属性