IPermission.Intersect(IPermission) 方法

定義

命名空間:

System.Security

組件:

System.Runtime.dll

建立並傳回目前權限與指定權限交集的權限。

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

參數

target

IPermission

要與目前權限產生交集的權限。 必須與目前權限屬於相同的類型。

傳回

IPermission

新使用權限，表示目前使用權限和指定使用權限的交集。 如果交集是空的，這個新權限就是 null。

例外狀況

ArgumentException

target 參數不是 null，而且執行個體與目前權限屬於不同類別。

範例

下列程式代碼範例示範如何實作 Intersect 方法。 此程式代碼範例是針對 類別提供的較大範例的 IPermission 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

備註

兩個許可權的交集是描述兩者共同描述之作業集的許可權。 只有傳遞兩個原始許可權的要求才會通過交集。

方法的所有實 Intersect 作都需要下列語句為 true。 X 和 Y 表示 IPermission 不是 null的物件參考。

• X. (交集) X 傳回等於 X的值。

• X.) 交集 (Y 傳回與 相同的值 Y。交集 (X) 。

• X. null) (交集傳 null回 。