CustomStrokes.Item 属性 (Int32)

项目
11/04/2008

获取 CustomStrokes 集合中指定索引处的 Strokes 集合。

命名空间： Microsoft.Ink
程序集： Microsoft.Ink（在 Microsoft.Ink.dll 中）

语法

声明
Public ReadOnly Property Item ( _
    index As Integer _
) As Strokes
用法
Dim instance As CustomStrokes
Dim index As Integer
Dim value As Strokes

value = instance.Item(index)

public Strokes Item[
    int index
] { get; }

public:
property Strokes^ Item[int index] {
    Strokes^ get (int index);
}

/** @property */
public Strokes get_Item(
    int index
)

JScript 不支持索引属性。

参数

index
类型：System.Int32
要获取的 Strokes 集合的从零开始的索引。

属性值

类型：Microsoft.Ink.Strokes
CustomStrokes 集合中的指定的 Strokes 集合。

备注

如果 index 与 CustomStrokes 集合的现有成员不匹配，则会引发 System.ArgumentOutOfRangeException。如果出于开发目的正在使用安装了 Tablet PC SDK 的 Windows XP（非 Tablet 版本），并且 index 与 CustomStrokes 集合的现有成员不匹配，则会引发 System.Runtime.Inter。

备注

在 C# 中，应按下例所示使用该集合的索引器，而不是使用该集合的 Item 属性。

示例

在此示例中，如果 Ink 对象的 CustomStrokes 集合在指定索引处包含 Strokes 集合，则方法返回 true。如果指定索引处没有 Strokes 集合，则会引发异常，并且方法返回 false。

Private Function CustomStrokesCollectionExists(ByVal mIndex As Integer, ByVal mInk As Ink) As Boolean
    Try
        Dim S As Strokes = mInk.CustomStrokes(mIndex)
        ' In VB, you can also access the named collections by using the Item property:
        ' Dim S As Strokes = mInk.CustomStrokes.Item(mIndex)
        '
        ' if the previous statement did not raise an exception, 
        ' the indexed Strokes collection exists
        Return True

    Catch E As System.Runtime.InteropServices.COMException
        ' For Windows XP (not Tablet Edition) with Tablet PC SDK installed for development purposes
        ' this exception is raised when the indexed collection does not exist

    Catch E As ArgumentOutOfRangeException
        ' For Windows XP Tablet Edition and Vista
        ' this exception is raised when the indexed collection does not exist

    Catch E As Exception
        ' in case another type of exception is raised

    End Try
    Return False
End Function

private bool CustomStrokesCollectionExists(int mIndex, Ink mInk)
{
    try
    {
        Strokes S = mInk.CustomStrokes[mIndex];
        // In C#, the Item property is not available. The following won't compile:
        // Strokes S = mInk.CustomStrokes.Item[mIndex];

        // if the previous statement did not throw an exception, 
        // the indexed Strokes collection exists
        return true;
    }

    catch (System.Runtime.InteropServices.COMException)
    {
        // For Windows XP (not Tablet Edition) with Tablet PC SDK installed for development purposes
        // this exception is raised when the indexed collection does not exist
    }
    catch (ArgumentOutOfRangeException)
    {
        // For Windows XP Tablet Edition and Vista
        // this exception is raised when the indexed collection does not exist
    }
    catch (Exception)
    {
        // in case another type of exception is raised
    }
    return false;
}