ScrollBar.Value 屬性

定義

命名空間:
System.Windows.Forms
組件:
System.Windows.Forms.dll
來源:
ScrollBar.cs
來源:
ScrollBar.cs
來源:
ScrollBar.cs
來源:
ScrollBar.cs
來源:
ScrollBar.cs

取得或設定一個數值，代表滾動條控制中滾動框的當前位置。

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

一個數值，且位於 Minimum and Maximum 範圍內。 預設值為 0。

屬性
BindableAttribute

例外狀況

ArgumentOutOfRangeException

分配價值低於房產 Minimum 價值。

-或-

分配價值高於房產 Maximum 價值。

範例

以下範例將圖片捲入一個圖片框。 它利用滾動條的 ， Value 每當使用者捲動時，重新繪製圖片的新部分。 這個程式碼範例是為類別概述提供 ScrollBar 的完整範例的一部分。

Note

關於如何在 Visual Studio 中執行此範例的說明，請參見 《如何編譯並執行完整的 Windows 表單程式碼範例，使用 Visual Studio》。

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

適用於