IPermission.Intersect(IPermission) 方法

定义

创建并返回一个权限,该权限是当前权限与指定权限的交集。

public:
 System::Security::IPermission ^ Intersect(System::Security::IPermission ^ target);
public System.Security.IPermission? Intersect (System.Security.IPermission? target);
public System.Security.IPermission Intersect (System.Security.IPermission target);
abstract member Intersect : System.Security.IPermission -> System.Security.IPermission
Public Function Intersect (target As IPermission) As IPermission

参数

target
IPermission

要与当前权限相交的权限。 它必须与当前权限属于同一类型。

返回

表示当前权限和指定权限的交集的一个新权限。 如果交集为空,则此新权限为 null

例外

target 参数不为 null,并且是与当前权限不属于同一类的实例。

示例

下面的代码示例演示如何实现 Intersect 方法。 此代码示例是为 IPermission 类提供的一个更大示例的一部分。

    // Return a new object that contains the intersection 
    // of 'this' and 'target'.
public:
    virtual IPermission^ Intersect(IPermission^ target) override
    {
        // If 'target' is null, return null.
        if (target == nullptr)
        {
            return nullptr;
        }

        // Both objects must be the same type.
        SoundPermission^ soundPerm = VerifyTypeMatch(target);

        // If 'this' and 'target' are unrestricted, 
        // return a new unrestricted permission.
        if (specifiedAsUnrestricted && soundPerm->specifiedAsUnrestricted)
        {
            return Clone(true, SoundPermissionState::PlayAnySound);
        }

        // Calculate the intersected permissions. 
        // If there are none, return null.
        SoundPermissionState minimumPermission = (SoundPermissionState)
            Math::Min((int) stateFlags, (int) soundPerm->stateFlags);
        if ((int)minimumPermission == 0)
        {
            return nullptr;
        }

        // Return a new object with the intersected permission value.
        return Clone(false, minimumPermission);
    }
// Return a new object that contains the intersection of 'this' and 'target'.
public override IPermission Intersect(IPermission target)
{
    // If 'target' is null, return null.
    if (target == null) return null;

    // Both objects must be the same type.
    SoundPermission soundPerm = VerifyTypeMatch(target);

    // If 'this' and 'target' are unrestricted, return a new unrestricted permission.
    if (m_specifiedAsUnrestricted && soundPerm.m_specifiedAsUnrestricted)
        return Clone(true, SoundPermissionState.PlayAnySound);

    // Calculate the intersected permissions. If there are none, return null.
    SoundPermissionState val = (SoundPermissionState)
        Math.Min((Int32)m_flags, (Int32)soundPerm.m_flags);
    if (val == 0) return null;

    // Return a new object with the intersected permission value.
    return Clone(false, val);
}
' Return a new object that contains the intersection of 'this' and 'target'.
Public Overrides Function Intersect(ByVal target As IPermission) As IPermission
    ' If 'target' is null, return null.
    If target Is Nothing Then
        Return Nothing
    End If
    ' Both objects must be the same type.
    Dim soundPerm As SoundPermission = VerifyTypeMatch(target)

    ' If 'this' and 'target' are unrestricted, return a new unrestricted permission.
    If m_specifiedAsUnrestricted AndAlso soundPerm.m_specifiedAsUnrestricted Then
        Return Clone(True, SoundPermissionState.PlayAnySound)
    End If
    ' Calculate the intersected permissions. If there are none, return null.
    Dim val As SoundPermissionState = CType(Math.Min(CType(m_flags, Int32), CType(soundPerm.m_flags, Int32)), SoundPermissionState)
    If val = 0 Then
        Return Nothing
    End If
    ' Return a new object with the intersected permission value.
    Return Clone(False, val)

End Function 'Intersect

注解

两个权限的交集是描述它们共同描述的操作集的权限。 只有传递两个原始权限的要求才会通过交集。

对于 方法的所有实现 Intersect ,以下语句必须为 true。 XY 表示 IPermission 不是 null的对象引用。

  • X.相交 (X) 返回等于 X的值。

  • X.相交 (Y) 返回与 相同的值 Y。 (X) 相交。

  • X.相交 (null) 返回 null

适用于