如何從對象列表填充樹視圖

Question

我在從對象列表填充樹視圖時遇到問題。 我一直在 google 上尋找解決方案，我找到了一些接近我的問題的主題，但沒有一個解決它。

我有一個包含每個對象屬性的列表：名稱和組。

我想像下面一樣填充我的樹視圖：

+---Group 1
|   |
|   +--------object.Name <-- 
|   +--------object.Name <-- all objects with object.Group = Group 1
|   +--------object.Name <--
|
+---Group 2
|   |
|   +--------object.Name <-- 
|   +--------object.Name <-- all objects with object.Group = Group 2
|   +--------object.Name <--
|

等等。

謝謝。

Answer 1

工作得很好，謝謝。 我剛剛在 else 的開頭和結尾添加了幾行，如下所示。

private void PopulateTreeView()
    {
        ListOfObjectsSorted = ListOfObjects.OrderBy(r => r.Group).ToList();
        var topNode = new TreeNode("Select all");
        treeView1.Nodes.Add(topNode);
        string currentGroup = ListOfObjectsSorted.First().Group;
        var treeNodes = new List<TreeNode>();
        var childNodes = new List<TreeNode>();
        foreach (Object obj in ListOfObjectsSorted )
        {
            if (currentGroup == rule.Group)
                childNodes.Add(new TreeNode(obj.Name));
            else
            {
                if (childNodes.Count > 0)
                {
                    treeNodes.Add(new TreeNode(currentGroup, childNodes.ToArray()));
                    childNodes = new List<TreeNode>();
                }
                childNodes.Add(new TreeNode(obj.Name));
                currentGroup = obj.Group;
            }
        }
        if (childNodes.Count > 0)
        {
            treeNodes.Add(new TreeNode(currentGroup, childNodes.ToArray()));
        }
        treeView1.Nodes[0].Nodes.AddRange(treeNodes.ToArray());
    }

Answer 2

您的問題是技術問題還是解決方法？ 您可以按 object.Group 排序，然后在每次組更改時創建一個頂級節點。

編輯：下面是一些示例代碼，我尚未對其進行測試，因此將其更多地視為指導：

string currentGroup = null;
List<TreeNode> treeNodes = new List<TreeNode>();
List<TreeNode> childNodes = new List<TreeNode>();
foreach (BusinessObject obj in objectList)
{
    if (currentGroup == obj.Group)
        childNodes.Add(new TreeNode(obj.Name));
    else
    {
        if (childNodes.Count > 0)
        {
            treeNodes.Add(new TreeNode(currentGroup, childNodes.ToArray()));
            childNodes = new List<TreeNode>();
        }
        currentGroup = obj.Group;
    }
}
if (childNodes.Count > 0)
{
    treeNodes.Add(new TreeNode(currentGroup, childNodes.ToArray()));
}
treeView.Nodes.AddRange(treeNodes.ToArray());

Answer 3

這里有一些在 VB 中...

嘗試

        Me.Cursor = Cursors.WaitCursor
        If rtb.Visible Then line = rtb.Lines
        Dim i, j As Integer
        Dim myLst As New ListBox
        Dim nod0 As New TreeNode
        Dim nod1 As New TreeNode
        Dim nodGet As New TreeNode
        Dim nodSet As New TreeNode
        'Aktualna pozicia
        If trw.SelectedNode Is Nothing Then
        Else
            nodGet = trw.SelectedNode
        End If

        For Each nod0 In trw.Nodes
            If nod0.IsExpanded Then
                myLst.Items.Add(nod0.Tag)
                For Each nod1 In nod0.Nodes
                    If nod1.IsExpanded Then myLst.Items.Add(nod1.Tag)
                Next
            End If
        Next

        Dim cntr() As Integer = {-1, -1, -1}

        trw.Nodes.Clear()
        trw.ShowPlusMinus = False
        trw.ShowRootLines = False
        trw.CheckBoxes = False
        For i = 0 To UBound(line)
            If Mid(line(i), 1, 1) = "\" Then
                j = line(i).IndexOf(dod)
                If j > 0 Then
                    s = Mid(line(i), 1, j)
                Else
                    s = line(i)
                End If
                If Mid(s, 1, 4) = "\\\\" Then
                    trw.Nodes.Add(Mid(s, 5))
                    cntr(0) = cntr(0) + 1
                    cntr(1) = -1
                    cntr(2) = -1
                    trw.Nodes(cntr(0)).Tag = s
                    trw.Nodes(cntr(0)).ImageIndex = 4
                    trw.Nodes(cntr(0)).SelectedImageIndex = 5
                    If trw.Nodes(cntr(0)).Tag = nodGet.Tag Then nodSet = trw.Nodes(cntr(0))
                Else
                    If Mid(s, 1, 3) = "\\\" Then
                        If cntr(0) = -1 Then trw.Nodes.Add("...") : cntr(0) = 0 : cntr(1) = -1
                        trw.Nodes(cntr(0)).Nodes.Add(Mid(s, 4))
                        cntr(1) = cntr(1) + 1
                        cntr(2) = -1
                        trw.Nodes(cntr(0)).Nodes(cntr(1)).Tag = trw.Nodes(cntr(0)).Tag.ToString & eol & s
                        trw.Nodes(cntr(0)).Nodes(cntr(1)).ImageIndex = 1
                        trw.Nodes(cntr(0)).Nodes(cntr(1)).SelectedImageIndex = 2
                        If trw.Nodes(cntr(0)).Nodes(cntr(1)).Tag = nodGet.Tag Then nodSet = trw.Nodes(cntr(0)).Nodes(cntr(1))
                    Else
                        If Mid(s, 1, 2) = "\\" Then
                            If cntr(0) = -1 Then trw.Nodes.Add("...") : cntr(0) = 0 : cntr(1) = -1
                            If cntr(1) = -1 Then trw.Nodes(cntr(0)).Nodes.Add("...") : cntr(1) = 0 : cntr(2) = -1
                            trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes.Add(Mid(s, 3))
                            cntr(2) = cntr(2) + 1
                            trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes(cntr(2)).Tag = trw.Nodes(cntr(0)).Nodes(cntr(1)).Tag.ToString & eol & s
                            trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes(cntr(2)).ImageIndex = 3
                            trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes(cntr(2)).SelectedImageIndex = 4
                            If trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes(cntr(2)).Tag = nodSet.Tag Then nodSet = trw.Nodes(cntr(0)).Nodes(cntr(1)).Nodes(cntr(2))
                        End If
                    End If
                End If
            End If
        Next i
        'Navrat na aktualnu poziciu
        Application.DoEvents()
        For i = 0 To myLst.Items.Count - 1
            For Each nod0 In trw.Nodes
                If nod0.Tag = myLst.Items(i).ToString Then nod0.Expand()
                For Each nod1 In nod0.Nodes
                    If nod1.Tag = myLst.Items(i).ToString Then nod1.Expand()
                Next
            Next
        Next i
        Application.DoEvents()
        If nodSet.Tag <> "" Then trw.SelectedNode = nodSet
    Catch ex As Exception
        MsgBox(ex.ToString, MsgBoxStyle.Exclamation)
    Finally
        Me.Cursor = Cursors.Default
    End Try

Answer 4

5年后……

調用 >> PrintProperties(null, yourObject, 0);

   public void PrintProperties(TreeNode parentNode, object obj, int indent)
    {

        if (obj == null) return;
        string indentString = new string(' ', indent);
        Type objType = obj.GetType();
        PropertyInfo[] properties = objType.GetProperties();
        foreach (PropertyInfo property in properties)
        {
            object propValue = new object();
            if (property.CanRead)
                propValue = property.GetValue(obj, null);
            if (IsSimpleType(property.PropertyType))
            {
                //Console.WriteLine("{0}{1}:", indentString, property.Name);
                if (parentNode != null)
                {
                    parentNode.Nodes.Add(property.Name, property.Name +": " + (propValue != null ? propValue.ToString() : string.Empty));
                }
                else
                {
                    treeView.Nodes.Add(property.Name, property.Name + ": " + (propValue != null ? propValue.ToString() : string.Empty));
                }

            }

            else if (typeof(IEnumerable).IsAssignableFrom(property.PropertyType))
            {
                TreeNode node;
                if (parentNode != null)
                {
                    node = parentNode.Nodes.Add(property.Name, property.Name);
                }
                else
                {
                    node = treeView.Nodes.Add(property.Name, property.Name);
                }

                //Console.WriteLine("{0}{1}:", indentString, property.Name);
                IEnumerable enumerable = (IEnumerable)propValue;
                foreach (object child in enumerable)
                    PrintProperties(node, child, indent + 2);
            }
            else
            {

                TreeNode node;
                if (parentNode != null)
                {
                    node = parentNode.Nodes.Add(property.Name, property.Name);
                }
                else
                {
                    node = treeView.Nodes.Add(property.Name, property.Name);
                }

                PrintProperties(node, propValue, indent + 2);
            }
        }
    }

    public static bool IsSimpleType(Type type)
    {
        return
            type.IsValueType ||
            type.IsPrimitive ||
            new Type[]
            {
        typeof(String),
        typeof(Decimal),
        typeof(DateTime),
        typeof(DateTimeOffset),
        typeof(TimeSpan),
        typeof(Guid)
            }.Contains(type) ||
            Convert.GetTypeCode(type) != TypeCode.Object;
    }

Answer 5

這是一個基於@PrepucioArgentino 的答案的版本，它可以更好地處理集合中的復雜類型以及結構。 您還可以忽略基於名稱的屬性（在整個結構中）。 但通常你會想在那里傳遞一個空列表。

    public static class TreeNodeHelper
    {

        public static void PrintProperties(TreeNode parentNode, object obj, int indent, TreeView treeView, ICollection<string> ignoredPropertyNames)
        {

            string indentString = new string(' ', indent); // used for debugging


            if (obj == null)
                return;

            var objType = obj.GetType();

            var properties = objType.GetProperties()
                .Where(x => !ignoredPropertyNames.Contains(x.Name))
                .ToList();

            foreach (var property in properties)
            {
                if (property.Name.ToUpper().Contains("DiagMessage".ToUpper()))
                {
                    // TODO rem test code
                }

                var propValue = new object();
                if (property.CanRead)
                    propValue = property.GetValue(obj, null);
                if (IsSimpleType(property.PropertyType))
                {
                    Debug.WriteLine("{0}{1}:", indentString, property.Name);
                    if (parentNode != null)
                    {
                        parentNode.Nodes.Add(property.Name,
                            $"{property.Name}: {(propValue != null ? propValue.ToString() : string.Empty)}");
                    }
                    else
                    {
                        treeView.Nodes.Add(property.Name,
                            $"{property.Name}: {(propValue != null ? propValue.ToString() : string.Empty)}");
                    }

                }

                else if (typeof(IEnumerable).IsAssignableFrom(property.PropertyType))
                {
                    TreeNode collectionRootNode;
                    if (parentNode != null)
                    {
                        collectionRootNode = parentNode.Nodes.Add(property.Name, property.Name);
                    }
                    else
                    {
                        collectionRootNode = treeView.Nodes.Add(property.Name, property.Name);
                    }

                    Debug.WriteLine("{0}{1}:", indentString, property.Name);
                    var enumerable = (IEnumerable)propValue;
                    var count = 0;
                    foreach (var child in enumerable)
                    {
                        count++;

                        if (!IsSimpleType(child.GetType()))
                        {
                            var entryRootNode = collectionRootNode.Nodes.Add($"{property.Name}[{count}]",
                                $"{property.Name}[{count}]");
                            PrintProperties(entryRootNode, child, indent + 2, treeView, ignoredPropertyNames);
                        }
                        else
                        {
                            collectionRootNode.Nodes.Add($"{property.Name}[{count}]", $"{property.Name}[{count}]: {child}");
                        }
                    }
                }
                else
                {

                    TreeNode node;
                    if (parentNode != null)
                    {
                        node = parentNode.Nodes.Add(property.Name, property.Name);
                    }
                    else
                    {
                        node = treeView.Nodes.Add(property.Name, property.Name);
                    }

                    PrintProperties(node, propValue, indent + 2, treeView, ignoredPropertyNames);
                }
            }
        }

        public static bool IsSimpleType(Type type)
        {
            if (type.IsGenericType && type.GetGenericTypeDefinition() == typeof(Nullable<>))
            {
                // nullable type, check if the nested type is simple.
                return IsSimpleType(type.GetGenericArguments()[0]);
            }

            return type.IsPrimitive
                   || ((IList)new[]
                   {
                       // Structs that are 'simple types', expand on this when needed.
                       typeof(DateTime),
                       typeof(DateTimeOffset),
                       typeof(TimeSpan),
                       typeof(Guid)
                   }).Contains(type)
                   || type.IsEnum
                   || type == typeof(string)
                   || type == typeof(decimal);
        }

    }

   TreeNodeHelper.PrintProperties(null, firstMotor, 0, treeView1, new List<string>(new[]{ "Creator", "PlcTag", "PlcComponentCreationInfo" }));