ScrollBar.Value 屬性

定義

命名空間:

System.Windows.Forms

組件:

System.Windows.Forms.dll

取得或設定表示捲軸控制項上的捲動方塊目前位置的數值。

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

[System.ComponentModel.Bindable(true)]
public int Value { get; set; }

[<System.ComponentModel.Bindable(true)>]
member this.Value : int with get, set

Public Property Value As Integer

屬性值

Int32

Minimum 及 Maximum 範圍中的數值。 預設值為 0。

屬性

BindableAttribute

例外狀況

ArgumentOutOfRangeException

指派的值小於 Minimum 屬性值。

-或-

指派的值大於 Maximum 屬性值。

範例

下列範例會在圖片方塊中捲動影像。 它會使用 Value 捲軸的 ，在使用者捲動時重新繪製影像的新部分。 此程式碼範例是類別概觀所提供較大範例的 ScrollBar 一部分。

注意

如需如何在 Visual Studio 中執行此範例的指示，請參閱如何：使用 Visual Studio 編譯和執行完整Windows Forms程式碼範例。

private void HandleScroll(Object sender, ScrollEventArgs e)
{
    //Create a graphics object and draw a portion of the image in the PictureBox.
    Graphics g = pictureBox1.CreateGraphics();

    int xWidth = pictureBox1.Width;
    int yHeight = pictureBox1.Height;

    int x;
    int y;

    if (e.ScrollOrientation == ScrollOrientation.HorizontalScroll)
    {
        x = e.NewValue;
        y = vScrollBar1.Value;
    }
    else //e.ScrollOrientation == ScrollOrientation.VerticalScroll
    {
        y = e.NewValue;
        x = hScrollBar1.Value;
    }

    g.DrawImage(pictureBox1.Image,
      new Rectangle(0, 0, xWidth, yHeight),  //where to draw the image
      new Rectangle(x, y, xWidth, yHeight),  //the portion of the image to draw
      GraphicsUnit.Pixel);

    pictureBox1.Update();
}

Private Sub HandleScroll(ByVal sender As [Object], ByVal e As ScrollEventArgs) _
  Handles vScrollBar1.Scroll, hScrollBar1.Scroll

    'Create a graphics object and draw a portion of the image in the PictureBox.
    Dim g As Graphics = pictureBox1.CreateGraphics()

    Dim xWidth As Integer = pictureBox1.Width
    Dim yHeight As Integer = pictureBox1.Height

    Dim x As Integer
    Dim y As Integer

    If (e.ScrollOrientation = ScrollOrientation.HorizontalScroll) Then

        x = e.NewValue
        y = vScrollBar1.Value

    Else 'e.ScrollOrientation == ScrollOrientation.VerticalScroll

        y = e.NewValue
        x = hScrollBar1.Value
    End If

    'First Rectangle: Where to draw the image.
    'Second Rectangle: The portion of the image to draw.

    g.DrawImage(pictureBox1.Image, _
      New Rectangle(0, 0, xWidth, yHeight), _
      New Rectangle(x, y, xWidth, yHeight), _
      GraphicsUnit.Pixel)

    pictureBox1.Update()
End Sub