TreeNodeCollection.Count 属性

定义

命名空间:

System.Windows.Forms

程序集:

System.Windows.Forms.dll

获取集合中 TreeNode 对象的总数。

public:
 property int Count { int get(); };

[System.ComponentModel.Browsable(false)]
public int Count { get; }

[<System.ComponentModel.Browsable(false)>]
member this.Count : int

Public ReadOnly Property Count As Integer

属性值

Int32

集合中的 TreeNode 对象的总数。

实现

Count

属性

BrowsableAttribute

示例

下面的代码示例显示 中的 对象数TreeNode，将集合的内容复制到数组Object中，并显示控件中Label树节点TreeNodeCollection的列表。 此示例要求具有 TreeView 在其 中至少有一个 TreeNodeLabel 的 ，并且 上的 控件FormTreeNodeCollection。

void CopyTreeNodes()
{
   // Get the collection of TreeNodes.
   TreeNodeCollection^ myNodeCollection = myTreeView->Nodes;
   int myCount = myNodeCollection->Count;
   myLabel->Text = String::Concat( myLabel->Text, "Number of nodes in the collection : ", myCount );
   myLabel->Text = String::Concat( myLabel->Text, "\n\nElements of the Array after Copying from the collection :\n" );
   
   // Create an Object array.
   array<Object^>^myArray = gcnew array<Object^>(myCount);
   
   // Copy the collection into an array.
   myNodeCollection->CopyTo( myArray, 0 );
   for ( int i = 0; i < myArray->Length; i++ )
   {
      myLabel->Text = myLabel->Text + (dynamic_cast<TreeNode^>(myArray[ i ]))->Text + "\n";

   }
}

private void CopyTreeNodes()
{
   // Get the collection of TreeNodes.
   TreeNodeCollection myNodeCollection = myTreeView.Nodes;
   int myCount = myNodeCollection.Count;

   myLabel.Text += "Number of nodes in the collection :" + myCount;
   myLabel.Text += "\n\nElements of the Array after Copying from the collection :\n";
   // Create an Object array.
   Object[] myArray = new Object[myCount];
   // Copy the collection into an array.
   myNodeCollection.CopyTo(myArray,0);
   for(int i=0; i<myArray.Length; i++)
   {
      myLabel.Text += ((TreeNode)myArray[i]).Text + "\n";
   }
}

Private Sub CopyTreeNodes()
   ' Get the collection of TreeNodes.
   Dim myNodeCollection As TreeNodeCollection = myTreeView.Nodes
   Dim myCount As Integer = myNodeCollection.Count

   myLabel.Text += "Number of nodes in the collection :" + myCount.ToString()

   myLabel.Text += ControlChars.NewLine + ControlChars.NewLine + _
     "Elements of the Array after Copying from the collection :" + ControlChars.NewLine

   ' Create an Object array.
   Dim myArray(myCount -1) As Object

   ' Copy the collection into an array.
   myNodeCollection.CopyTo(myArray, 0)
   Dim i As Integer
   For i = 0 To myArray.Length - 1
      myLabel.Text += CType(myArray(i), TreeNode).Text + ControlChars.NewLine
   Next i
End Sub

注解

属性 Count 包含分配给集合的对象数 TreeNode 。 可以使用 Count 属性值作为循环的上限来循环访问集合。

注意

由于集合的索引值是从零开始的索引，因此必须从循环变量中减去一个索引。 如果不考虑这一点，将超出集合的上限并引发 IndexOutOfRangeException 异常。