ScrollBar.LargeChange 属性
定义
重要
一些信息与预发行产品相关，相应产品在发行之前可能会进行重大修改。 对于此处提供的信息，Microsoft 不作任何明示或暗示的担保。
获取或设置一个值，当滚动框长距离移动时向 Value 属性加上该值或从中减去该值。
public:
property int LargeChange { int get(); void set(int value); };public int LargeChange { get; set; }member this.LargeChange : int with get, setPublic Property LargeChange As Integer属性值
一个数值。 默认值为 10。
例外
所分配的值小于 0。
示例
以下示例假定你已创建一个、已向该Form对象添加一个FormPictureBox、添加水平HScrollBar和垂直VScrollBarPictureBox值。 此代码示例是为类概述提供的大型示例的 ScrollBar 一部分。
在此示例中，属性 LargeChange 相对于大小设置 PictureBox。
必须添加对命名空间的System.DrawingSystem.Windows.Forms引用才能运行此示例。
备注
有关如何在Visual Studio中运行此示例的说明，请参阅如何：使用 Visual Studio 编译和运行完整的Windows 窗体代码示例。
public void SetScrollBarValues()
{
//Set the following scrollbar properties:
//Minimum: Set to 0
//SmallChange and LargeChange: Per UI guidelines, these must be set
// relative to the size of the view that the user sees, not to
// the total size including the unseen part. In this example,
// these must be set relative to the picture box, not to the image.
//Maximum: Calculate in steps:
//Step 1: The maximum to scroll is the size of the unseen part.
//Step 2: Add the size of visible scrollbars if necessary.
//Step 3: Add an adjustment factor of ScrollBar.LargeChange.
//Configure the horizontal scrollbar
//---------------------------------------------
if (this.hScrollBar1.Visible)
{
this.hScrollBar1.Minimum = 0;
this.hScrollBar1.SmallChange = this.pictureBox1.Width / 20;
this.hScrollBar1.LargeChange = this.pictureBox1.Width / 10;
this.hScrollBar1.Maximum = this.pictureBox1.Image.Size.Width - pictureBox1.ClientSize.Width; //step 1
if (this.vScrollBar1.Visible) //step 2
{
this.hScrollBar1.Maximum += this.vScrollBar1.Width;
}
this.hScrollBar1.Maximum += this.hScrollBar1.LargeChange; //step 3
}
//Configure the vertical scrollbar
//---------------------------------------------
if (this.vScrollBar1.Visible)
{
this.vScrollBar1.Minimum = 0;
this.vScrollBar1.SmallChange = this.pictureBox1.Height / 20;
this.vScrollBar1.LargeChange = this.pictureBox1.Height / 10;
this.vScrollBar1.Maximum = this.pictureBox1.Image.Size.Height - pictureBox1.ClientSize.Height; //step 1
if (this.hScrollBar1.Visible) //step 2
{
this.vScrollBar1.Maximum += this.hScrollBar1.Height;
}
this.vScrollBar1.Maximum += this.vScrollBar1.LargeChange; //step 3
}
}
Public Sub SetScrollBarValues()
'Set the following scrollbar properties:
'Minimum: Set to 0
'SmallChange and LargeChange: Per UI guidelines, these must be set
' relative to the size of the view that the user sees, not to
' the total size including the unseen part. In this example,
' these must be set relative to the picture box, not to the image.
'Maximum: Calculate in steps:
'Step 1: The maximum to scroll is the size of the unseen part.
'Step 2: Add the size of visible scrollbars if necessary.
'Step 3: Add an adjustment factor of ScrollBar.LargeChange.
'Configure the horizontal scrollbar
'---------------------------------------------
If (Me.hScrollBar1.Visible) Then
Me.hScrollBar1.Minimum = 0
Me.hScrollBar1.SmallChange = CInt(Me.pictureBox1.Width / 20)
Me.hScrollBar1.LargeChange = CInt(Me.pictureBox1.Width / 10)
Me.hScrollBar1.Maximum = Me.pictureBox1.Image.Size.Width - pictureBox1.ClientSize.Width 'step 1
If (Me.vScrollBar1.Visible) Then 'step 2
Me.hScrollBar1.Maximum += Me.vScrollBar1.Width
End If
Me.hScrollBar1.Maximum += Me.hScrollBar1.LargeChange 'step 3
End If
'Configure the vertical scrollbar
'---------------------------------------------
If (Me.vScrollBar1.Visible) Then
Me.vScrollBar1.Minimum = 0
Me.vScrollBar1.SmallChange = CInt(Me.pictureBox1.Height / 20)
Me.vScrollBar1.LargeChange = CInt(Me.pictureBox1.Height / 10)
Me.vScrollBar1.Maximum = Me.pictureBox1.Image.Size.Height - pictureBox1.ClientSize.Height 'step 1
If (Me.hScrollBar1.Visible) Then 'step 2
Me.vScrollBar1.Maximum += Me.hScrollBar1.Height
End If
Me.vScrollBar1.Maximum += Me.vScrollBar1.LargeChange 'step 3
End If
End Sub
注解
当用户在滚动框两侧的滚动条轨道中单击时，该 Value 属性会根据属性中 LargeChange 设置的值更改。
备注
可以处理按键事件，以便在用户按 PAGE UP 或 PAGE DOWN 键时滚动框移动。
用户界面指南建议， SmallChange 与用户看到的视图大小相对设置和 LargeChange 属性，而不是总大小（包括不可见部分）。 例如，如果你有一个显示大图像的滚动条的图片框， SmallChange 则应相对于图片框的大小（而不是图像的大小）设置和 LargeChange 属性。