Question

我有一个自定义的TreeView类。我不喜欢文字和背景颜色的排列方式。文本看起来很高（或背景太低）：

我没有看到任何定位文字的方法，所以我尝试将背景的Y位置向上移动2个像素。这会导致行出现时从一个节点点击到另一个节点：

我认为以前的节点背景没有重新绘制，但我认为我在CustomTreeView.OnPaint()部分的else // not selected部分中有代码

我能做些什么，或者这就是它必须的方式？

public class CustomTreeView : TreeView
    {
        public CustomTreeView() : base()
        {
            this.SetStyle(
                ControlStyles.UserPaint |
                ControlStyles.DoubleBuffer |
                ControlStyles.Opaque, true);
        }

        protected override void OnPaint(PaintEventArgs e)
        {
            using (System.Drawing.SolidBrush BackGroundBrushWindows = new System.Drawing.SolidBrush(System.Drawing.SystemColors.Window))
            using (System.Drawing.SolidBrush ForeGroundBrushWindows = new System.Drawing.SolidBrush(System.Drawing.SystemColors.WindowText))
            using (System.Drawing.SolidBrush BackGroundBrushHighLight = new System.Drawing.SolidBrush(System.Drawing.Color.CornflowerBlue))
            //using (System.Drawing.SolidBrush ForeGroundBrushHighLight = new System.Drawing.SolidBrush(System.Drawing.SystemColors.WindowText))
            {
                e.Graphics.FillRectangle(BackGroundBrushWindows, e.ClipRectangle);
                System.Drawing.SolidBrush CurrentNode;

                int count = this.Nodes.Count;
                System.Diagnostics.Trace.WriteLine("\nCustomTreeView.OnPaint: count: " + count);
                for (int topLevelIndex = 0; topLevelIndex < count; ++topLevelIndex)
                {
                    TreeNode topLevelTreeNode = Nodes[topLevelIndex];
                    CurrentNode = ForeGroundBrushWindows; // top level always this, never selected
                    e.Graphics.DrawString(topLevelTreeNode.Text, this.Font, CurrentNode, Rectangle.Inflate(topLevelTreeNode.Bounds, 2, 0));

                    int nodeCount = topLevelTreeNode.GetNodeCount(true);
                    System.Diagnostics.Trace.WriteLine("OnPaint: Nodes[index].GetNodeCount: " + nodeCount);

                    foreach (TreeNode childNode in topLevelTreeNode.Nodes)
                    {
                        System.Diagnostics.Trace.WriteLine("\tchildNode: " + childNode.Tag + "\tIsSelected: " + childNode.IsSelected);
                        if (childNode.IsSelected)
                        {
                            //CurrentNode = ForeGroundBrushWindows;
                            Rectangle bounds = childNode.Bounds;
                            //bounds.Y += -2; // move up 2
                            e.Graphics.FillRectangle(BackGroundBrushHighLight, bounds);
                        }
                        else // not selected
                        {
                            //CurrentNode = ForeGroundBrushWindows;
                            Rectangle bounds = childNode.Bounds;
                            //bounds.Y += -2; // move up 2
                            e.Graphics.FillRectangle(BackGroundBrushWindows, bounds);
                        }

                        if (childNode.Parent.IsExpanded)
                        {
                            Rectangle bounds = childNode.Bounds;
                            //bounds.Y += -2; // move up 2
                            e.Graphics.DrawString(childNode.Text, this.Font, CurrentNode, Rectangle.Inflate(bounds, 2, 0));
                        }
                    }
                }

            }
        }
    }

      public partial class TreeViewDialog : Form
    {

        //  Add unselectable nodes to this collection when you create them
        private List<TreeNode> _unselectableNodes = new List<TreeNode>();

        public TreeViewDialog (String documentType)
        {

            InitializeComponent();

            this.treeView.Update();

            // Add (key, text), where key is name of the tree node and text is the text to display
            TreeNode treeNodeClassical = this.treeView.Nodes.Add(ProjectConstants.TOP_NODE_CLASSICAL, ProjectConstants.TOP_NODE_CLASSICAL);
            treeNodeClassical.Tag = ProjectConstants.TOP_NODE_CLASSICAL;
            _unselectableNodes.Add(treeNodeClassical);

            TreeNode treeNode = treeNodeClassical.Nodes.Add(ProjectConstants.CLASSICAL_BEETHOVEN, ProjectConstants.CLASSICAL_BEETHOVEN);
            treeNode.Tag = ProjectConstants.CLASSICAL_BEETHOVEN;
            treeNode = treeNodeClassical.Nodes.Add(ProjectConstants.CLASSICAL_MOZART, ProjectConstants.CLASSICAL_MOZART);
            treeNode.Tag = ProjectConstants.CLASSICAL_MOZART;
            treeNode = treeNodeClassical.Nodes.Add(ProjectConstants.CLASSICAL_CHOPIN, ProjectConstants.CLASSICAL_CHOPIN);
            treeNode.Tag = ProjectConstants.CLASSICAL_CHOPIN;

            TreeNode treeNodeJazz = this.treeView.Nodes.Add(ProjectConstants.TOP_NODE_JAZZ, ProjectConstants.TOP_NODE_JAZZ);
            treeNodeJazz.Tag = ProjectConstants.TOP_NODE_JAZZ;
            _unselectableNodes.Add(treeNodeJazz);

            treeNode = treeNodeJazz.Nodes.Add(ProjectConstants.JAZZ_MONK, ProjectConstants.JAZZ_MONK);
            treeNode.Tag = ProjectConstants.JAZZ_MONK;
            treeNode = treeNodeJazz.Nodes.Add(ProjectConstants.JAZZ_MINGUS, ProjectConstants.JAZZ_MINGUS);
            treeNode.Tag = ProjectConstants.JAZZ_MINGUS;
            treeNode = treeNodeJazz.Nodes.Add(ProjectConstants.JAZZ_COLTRANE, ProjectConstants.JAZZ_COLTRANE);
            treeNode.Tag = ProjectConstants.JAZZ_COLTRANE;
            treeNode = treeNodeJazz.Nodes.Add(ProjectConstants.JAZZ_GILLESPIE, ProjectConstants.JAZZ_GILLESPIE);
            treeNode.Tag = ProjectConstants.JAZZ_GILLESPIE;


            TreeNode treeNodeRock = this.treeView.Nodes.Add(ProjectConstants.TOP_NODE_ROCK, ProjectConstants.TOP_NODE_ROCK);
            treeNodeRock.Tag = ProjectConstants.TOP_NODE_ROCK;
            _unselectableNodes.Add(treeNodeRock);

            treeNode = treeNodeRock.Nodes.Add(ProjectConstants.ROCK_CORNELL, ProjectConstants.ROCK_CORNELL);
            treeNode.Tag = ProjectConstants.ROCK_CORNELL;
            treeNode = treeNodeRock.Nodes.Add(ProjectConstants.ROCK_PLANT, ProjectConstants.ROCK_PLANT);
            treeNode.Tag = ProjectConstants.ROCK_PLANT;
            treeNode = treeNodeRock.Nodes.Add(ProjectConstants.ROCK_BJORK, ProjectConstants.ROCK_BJORK);
            treeNode.Tag = ProjectConstants.ROCK_BJORK;
            treeNode = treeNodeRock.Nodes.Add(ProjectConstants.ROCK_SPRINGSTEEN, ProjectConstants.ROCK_SPRINGSTEEN);
            treeNode.Tag = ProjectConstants.ROCK_SPRINGSTEEN;
            treeNode = treeNodeRock.Nodes.Add(ProjectConstants.ROCK_LADY_GAGA, ProjectConstants.ROCK_LADY_GAGA);
            treeNode.Tag = ProjectConstants.ROCK_LADY_GAGA;

            this.treeView.ExpandAll();

            // if something was selected on the tab page, then select it here
            if (!String.IsNullOrEmpty(documentType))
            {
                TreeNode namedNode = null;
                foreach (TreeNode node in treeView.Nodes)
                {
                    namedNode = getTreeNodeFromName(documentType, node);
                    if (namedNode != null)
                    {
                        break; // nothing found
                    }
                }

                if (namedNode != null)
                {
                    treeView.SelectedNode = namedNode; 
                }
                treeView.Focus();

            }

            this.treeView.EndUpdate();
        }

        public TreeNode getTreeNodeFromName(string name, TreeNode rootNode)
        {
            foreach (TreeNode node in rootNode.Nodes)
            {
                if (node.Name.Equals(name))
                {
                    return node;
                }
                TreeNode next = getTreeNodeFromName(name, node);
                if (next != null)
                {
                    return next;
                }
            }
            return null;
        }

        private void btnSave_Click(object sender, EventArgs e)
        {
            // nothing right now
        }


        private void btnCancel_Click(object sender, EventArgs e)
        {
            this.Close();
        }

        private void treeViewCategoryType_TreeNodeMouseClickEventHandler(object sender, TreeNodeMouseClickEventArgs eventArgs)
        {            TreeView treeView = (TreeView)sender;

            TreeNode treeNode = eventArgs.Node; // parent or child

            String nodeText = treeNode.Text;

            // if parent treeNode
            if (nodeText.Equals(ProjectConstants.TOP_NODE_CLASSICAL) ||
                nodeText.Equals(ProjectConstants.TOP_NODE_JAZZ) ||
                nodeText.Equals(ProjectConstants.TOP_NODE_ROCK))
            {
                // don't select the treeNode
            }
            else
            {  // child
            }

        }

        private void treeViewCategoryType_BeforeSelect(object sender, TreeViewCancelEventArgs eventArgs)
        {
            if (_unselectableNodes.Contains(eventArgs.Node))
            {
                eventArgs.Cancel = true;
            }
        }
    }

Answer 1

尝试在e.Graphics.DrawString(childNode.Text, this.Font, CurrentNode, Rectangle.Inflate(bounds, 2, -3));，

处进行更改

DrawString

for(Item task:tasks){ task.load(); Task tde=(Task) task; System.out.println(tde.getSubject()); System.out.println(tde.getBody()); System.out.println(tde.getStartDate()); System.out.println(tde.getDueDate()); }函数的最后一个参数接受一个Rectangle，并且该矩形具有您想要的Y值。 0是您告诉的不需要的，因此它应该具有负值以将文本推送到底部。

希望有所帮助，

文本和背景在TreeView中的位置

1 个答案: