SqlParameterCollection.Remove 方法

  • 参考

定义

命名空间:
System.Data.SqlClient
程序集:
System.Data.SqlClient.dll
程序集:
System.Data.dll
包:
System.Data.SqlClient v4.8.6

从集合中移除指定的 SqlParameter。

重载

Remove(SqlParameter)

从集合中移除指定的 SqlParameter。
Remove(Object)

从集合中移除指定的 SqlParameter。

Remove(SqlParameter)

从集合中移除指定的 SqlParameter。

public:
 void Remove(System::Data::SqlClient::SqlParameter ^ value);
public void Remove (System.Data.SqlClient.SqlParameter value);
override this.Remove : System.Data.SqlClient.SqlParameter -> unit
Public Sub Remove (value As SqlParameter)

参数

value
SqlParameter

要从集合中移除的 SqlParameter 对象。

例外

InvalidCastException

该参数不是 SqlParameter。

SystemException

集合中不存在该参数。

示例

以下示例在集合中SqlParameterCollection搜索 SqlParameter 对象。 如果 参数存在，则示例将删除它。 此示例假定 SqlParameterCollection 集合已由 SqlCommand创建。

public void SearchSqlParams()
{
    // ...
    // create SqlCommand command and SqlParameter param
    // ...
    if (command.Parameters.Contains(param))
        command.Parameters.Remove(param);
}

Public Sub SearchSqlParams()
    ' ...
    ' create SqlCommand command and SqlParameter param
    ' ...
    If command.Parameters.Contains(param) Then
        command.Parameters.Remove(param)
    End If
End Sub

另请参阅

适用于

Remove(Object)

从集合中移除指定的 SqlParameter。

public:
 override void Remove(System::Object ^ value);
public:
 virtual void Remove(System::Object ^ value);
public override void Remove (object value);
public void Remove (object value);
override this.Remove : obj -> unit
abstract member Remove : obj -> unit
override this.Remove : obj -> unit
Public Overrides Sub Remove (value As Object)
Public Sub Remove (value As Object)

参数

value
Object

要从集合中移除的对象。

实现

Remove(Object)

示例

下面的示例演示 IList 接口的实现以创建具有固定大小的简单列表。 此代码是 接口的更大示例的 IList 一部分。

class SimpleList : IList
{
    private object[] _contents = new object[8];
    private int _count;

    public SimpleList()
    {
        _count = 0;
    }

    // IList Members
    public int Add(object value)
    {
        if (_count < _contents.Length)
        {
            _contents[_count] = value;
            _count++;

            return (_count - 1);
        }

        return -1;
    }

    public void Clear()
    {
        _count = 0;
    }

    public bool Contains(object value)
    {
        for (int i = 0; i < Count; i++)
        {
            if (_contents[i] == value)
            {
                return true;
            }
        }
        return false;
    }

    public int IndexOf(object value)
    {
        for (int i = 0; i < Count; i++)
        {
            if (_contents[i] == value)
            {
                return i;
            }
        }
        return -1;
    }

    public void Insert(int index, object value)
    {
        if ((_count + 1 <= _contents.Length) && (index < Count) && (index >= 0))
        {
            _count++;

            for (int i = Count - 1; i > index; i--)
            {
                _contents[i] = _contents[i - 1];
            }
            _contents[index] = value;
        }
    }

    public bool IsFixedSize
    {
        get
        {
            return true;
        }
    }

    public bool IsReadOnly
    {
        get
        {
            return false;
        }
    }

    public void Remove(object value)
    {
        RemoveAt(IndexOf(value));
    }

    public void RemoveAt(int index)
    {
        if ((index >= 0) && (index < Count))
        {
            for (int i = index; i < Count - 1; i++)
            {
                _contents[i] = _contents[i + 1];
            }
            _count--;
        }
    }

    public object this[int index]
    {
        get
        {
            return _contents[index];
        }
        set
        {
            _contents[index] = value;
        }
    }

    // ICollection members.

    public void CopyTo(Array array, int index)
    {
        for (int i = 0; i < Count; i++)
        {
            array.SetValue(_contents[i], index++);
        }
    }

    public int Count
    {
        get
        {
            return _count;
        }
    }

    public bool IsSynchronized
    {
        get
        {
            return false;
        }
    }

    // Return the current instance since the underlying store is not
    // publicly available.
    public object SyncRoot
    {
        get
        {
            return this;
        }
    }

    // IEnumerable Members

    public IEnumerator GetEnumerator()
    {
        // Refer to the IEnumerator documentation for an example of
        // implementing an enumerator.
        throw new NotImplementedException("The method or operation is not implemented.");
    }

    public void PrintContents()
    {
        Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.");
        Console.Write("List contents:");
        for (int i = 0; i < Count; i++)
        {
            Console.Write($" {_contents[i]}");
        }
        Console.WriteLine();
    }
}

Public Class SimpleList
    Implements IList

    Private _contents(7) As Object
    Private _count As Integer

    Public Sub New()

        _count = 0
    End Sub

    ' IList members.
    Public Function Add(ByVal value As Object) As Integer Implements IList.Add
        If _count < _contents.Length Then
            _contents(_count) = value
            _count += 1

            Return _count - 1
        End If

        Return -1
    End Function

    Public Sub Clear() Implements IList.Clear
        _count = 0
    End Sub

    Public Function Contains(ByVal value As Object) As Boolean Implements IList.Contains
        For i As Integer = 0 To Count - 1
            If _contents(i) = value Then Return True
        Next

        Return False
    End Function

    Public Function IndexOf(ByVal value As Object) As Integer Implements IList.IndexOf
        For i As Integer = 0 To Count - 1
            If _contents(i) = value Then Return i
        Next
        Return -1
    End Function

    Public Sub Insert(ByVal index As Integer, ByVal value As Object) Implements IList.Insert

        If _count + 1 <= _contents.Length AndAlso index < Count AndAlso index >= 0 Then
            _count += 1

            For i As Integer = Count - 1 To index Step -1
                _contents(i) = _contents(i - 1)
            Next
            _contents(index) = value
        End If
    End Sub

    Public ReadOnly Property IsFixedSize() As Boolean Implements IList.IsFixedSize
        Get
            Return True
        End Get
    End Property

    Public ReadOnly Property IsReadOnly() As Boolean Implements IList.IsReadOnly
        Get
            Return False
        End Get
    End Property

    Public Sub Remove(ByVal value As Object) Implements IList.Remove
        RemoveAt(IndexOf(value))
    End Sub

    Public Sub RemoveAt(ByVal index As Integer) Implements IList.RemoveAt

        if index >= 0 AndAlso index < Count Then
            for i As Integer = index To Count - 2
                _contents(i) = _contents(i + 1)
            Next
            _count -= 1
        End If
    End Sub

    Public Property Item(ByVal index As Integer) As Object Implements IList.Item
        Get
            Return _contents(index)
        End Get

        Set(ByVal value As Object)
            _contents(index) = value
        End Set
    End Property

    ' ICollection members.
    Public Sub CopyTo(ByVal array As Array, ByVal index As Integer) Implements ICollection.CopyTo
        For i As Integer = 0 To Count - 1
            array.SetValue(_contents(i), index)
            index += 1
        Next
    End Sub

    Public ReadOnly Property Count() As Integer Implements ICollection.Count
        Get
            Return _count
        End Get
    End Property

    Public ReadOnly Property IsSynchronized() As Boolean Implements ICollection.IsSynchronized
        Get
            Return False
        End Get
    End Property

    ' Return the current instance since the underlying store is not
    ' publicly available.
    Public ReadOnly Property SyncRoot() As Object Implements ICollection.SyncRoot
        Get
            Return Me
        End Get
    End Property

    ' IEnumerable members.
    Public Function GetEnumerator() As IEnumerator Implements IEnumerable.GetEnumerator

        ' Refer to the IEnumerator documentation for an example of
        ' implementing an enumerator.
        Throw New NotImplementedException("The method or operation is not implemented.")
    End Function

    Public Sub PrintContents()
        Console.WriteLine($"List has a capacity of {_contents.Length} and currently has {_count} elements.")
        Console.Write("List contents:")

        For i As Integer = 0 To Count - 1
            Console.Write($" {_contents(i)}")
        Next

        Console.WriteLine()
    End Sub
End Class

注解

此成员是显式接口成员的实现。 它只能在 SqlParameterCollection 实例被强制转换为 IList 接口时使用。

在由连续的元素组成的集合（如列表）中，已移除元素下面的元素将上移以占据空出的位置。 如果集合具有索引，则移动的元素的索引也将更新。 此行为不适用于元素按概念划分为不同存储桶的集合，如哈希表。 如果在 value 中找不到 IList，则 IList保持不变且不引发异常。

另请参阅

适用于