TreeView.ShowRootLines 属性

获取或设置一个值，用以指示是否在树视图根处的树节点之间绘制连线。

**命名空间:**System.Windows.Forms
**程序集:**System.Windows.Forms（在 system.windows.forms.dll 中）

语法

声明
Public Property ShowRootLines As Boolean
用法
Dim instance As TreeView
Dim value As Boolean

value = instance.ShowRootLines

instance.ShowRootLines = value

public bool ShowRootLines { get; set; }

public:
property bool ShowRootLines {
    bool get ();
    void set (bool value);
}

/** @property */
public boolean get_ShowRootLines ()

/** @property */
public void set_ShowRootLines (boolean value)

public function get ShowRootLines () : boolean

public function set ShowRootLines (value : boolean)

属性值

如果在树视图根处的树节点之间绘制连线，则为 true；否则为 false。默认为 true。

备注

如果 ShowRootLines 属性为 false，根树节点旁将不会显示加号和减号按钮，而 ShowPlusMinus 属性将失效。

示例

下面的代码示例演示如何使用 BorderStyle 枚举以及BorderStyle、ShowLines、Scrollable、HideSelection 和 ShowRootLines 属性。若要运行该示例，请将以下代码粘贴到一个窗体中，并从该窗体的构造函数或 Load 方法中调用 InitializeTreeView 方法。

' Declare the TreeView control.
Friend WithEvents TreeView1 As System.Windows.Forms.TreeView

' Initialize the TreeView to blend with the form, giving it the 
' same color as the form and no border.
Private Sub InitializeTreeView()

    ' Create a new TreeView control and set the location and size.
    Me.TreeView1 = New System.Windows.Forms.TreeView
    Me.TreeView1.Location = New System.Drawing.Point(72, 48)
    Me.TreeView1.Size = New System.Drawing.Size(200, 200)

    ' Set the BorderStyle property to none, the BackColor property to  
    ' the form's backcolor, and the Scrollable property to false.  
    ' This allows the TreeView to blend in form.
    Me.TreeView1.BorderStyle = BorderStyle.None
    Me.TreeView1.BackColor = Me.BackColor
    Me.TreeView1.Scrollable = False

    
    ' Set the ShowRootLines and ShowLines properties to false to 
    ' give the TreeView a list-like appearance.
    Me.TreeView1.ShowRootLines = False
    Me.TreeView1.ShowLines = False

    ' Add the nodes.
    Me.TreeView1.Nodes.AddRange(New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode("Features", _
        New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode("Full Color"), _
        New System.Windows.Forms.TreeNode("Project Wizards"), _
        New System.Windows.Forms.TreeNode("Visual C# and Visual Basic Support")}), _
        New System.Windows.Forms.TreeNode("System Requirements", _
        New System.Windows.Forms.TreeNode() _
        {New System.Windows.Forms.TreeNode _
        ("Pentium 133 MHz or faster processor "), _
        New System.Windows.Forms.TreeNode("Windows 98 or later"), _
        New System.Windows.Forms.TreeNode("100 MB Disk space")})})

    ' Set the tab index and add the TreeView to the form.
    Me.TreeView1.TabIndex = 0
    Me.Controls.Add(Me.TreeView1)
End Sub

// Declare the TreeView control.
internal System.Windows.Forms.TreeView TreeView1;

// Initialize the TreeView to blend with the form, giving it the 
// same color as the form and no border.
private void InitializeTreeView()
{

    // Create a new TreeView control and set the location and size.
    this.TreeView1 = new System.Windows.Forms.TreeView();
    this.TreeView1.Location = new System.Drawing.Point(72, 48);
    this.TreeView1.Size = new System.Drawing.Size(200, 200);

    // Set the BorderStyle property to none, the BackColor property to  
    // the form's backcolor, and the Scrollable property to false.  
    // This allows the TreeView to blend in form.

    this.TreeView1.BorderStyle = BorderStyle.None;
    this.TreeView1.BackColor = this.BackColor;
    this.TreeView1.Scrollable = false;

    // Set the HideSelection property to false to keep the 
    // selection highlighted when the user leaves the control. 
    // This helps it blend with form.
    this.TreeView1.HideSelection = false;

    // Set the ShowRootLines and ShowLines properties to false to 
    // give the TreeView a list-like appearance.
    this.TreeView1.ShowRootLines = false;
    this.TreeView1.ShowLines = false;

    // Add the nodes.
    this.TreeView1.Nodes.AddRange(new TreeNode[]
        {new TreeNode("Features", 
            new TreeNode[]{
            new TreeNode("Full Color"), 
            new TreeNode("Project Wizards"), 
            new TreeNode("Visual C# and Visual Basic Support")}), 
            new TreeNode("System Requirements", 
            new TreeNode[]{
                new TreeNode("Pentium 133 MHz or faster processor "),
                new TreeNode("Windows 98 or later"), 
                new TreeNode("100 MB Disk space")})
        });

    // Set the tab index and add the TreeView to the form.
    this.TreeView1.TabIndex = 0;
    this.Controls.Add(this.TreeView1);
}

// Declare the TreeView control.
System.Windows.Forms.TreeView treeView1;

// Initialize the TreeView to blend with the form, giving it the 
// same color as the form and no border.
private void InitializeTreeView()
{
    // Create a new TreeView control and set the location and size.
    this.treeView1 = new System.Windows.Forms.TreeView();
    this.treeView1.set_Location(new System.Drawing.Point(72, 48));
    this.treeView1.set_Size(new System.Drawing.Size(200, 200));
    // Set the BorderStyle property to none, the BackColor property to
    // the form's backcolor, and the Scrollable property to false.  
    // This allows the TreeView to blend in form.
    this.treeView1.set_BorderStyle(BorderStyle.None);
    this.treeView1.set_BackColor(this.get_BackColor());
    this.treeView1.set_Scrollable(false);
    // Set the HideSelection property to false to keep the 
    // selection highlighted when the user leaves the control. 
    // This helps it blend with form.
    this.treeView1.set_HideSelection(false);
    // Set the ShowRootLines and ShowLines properties to false to 
    // give the TreeView a list-like appearance.
    this.treeView1.set_ShowRootLines(false);
    this.treeView1.set_ShowLines(false);
    // Add the nodes.
    this.treeView1.get_Nodes().AddRange(
        new TreeNode[] {new TreeNode("Features",
        new TreeNode[] { new TreeNode("Full Color"),
        new TreeNode("Project Wizards"),
        new TreeNode("Visual C# and Visual Basic Support") }),
        new TreeNode("System Requirements",
        new TreeNode[] {
        new TreeNode("Pentium 133 MHz or faster processor "),
        new TreeNode("Windows 98 or later"),
        new TreeNode("100 MB Disk space") }) });
    // Set the tab index and add the TreeView to the form.
    this.treeView1.set_TabIndex(0);
    this.get_Controls().Add(this.treeView1);
} //InitializeTreeView

平台

Windows 98、Windows 2000 SP4、Windows CE、Windows Millennium Edition、Windows Mobile for Pocket PC、Windows Mobile for Smartphone、Windows Server 2003、Windows XP Media Center Edition、Windows XP Professional x64 Edition、Windows XP SP2、Windows XP Starter Edition

.NET Framework 并不是对每个平台的所有版本都提供支持。有关受支持版本的列表，请参见系统要求。

版本信息

.NET Framework

受以下版本支持：2.0、1.1、1.0

.NET Compact Framework

受以下版本支持：2.0、1.0

请参见

参考

TreeView 类
TreeView 成员
System.Windows.Forms 命名空间
TreeView.ShowPlusMinus 属性