c# - Gtk# NodeView 彩色行

Question

我使用 NodeView 对象以这种方式向用户输出数据(Gtk# 教程):

    [Gtk.TreeNode (ListOnly=true)]
    public class MyTreeNode : Gtk.TreeNode {

            string song_title;

            public MyTreeNode (string artist, string song_title)
            {
                    Artist = artist;
                    this.song_title = song_title; 
            }

            [Gtk.TreeNodeValue (Column=0)]
            public string Artist;

            [Gtk.TreeNodeValue (Column=1)]
            public string SongTitle {get { return song_title; } }
    }

Gtk.NodeStore store;
    Gtk.NodeStore Store 
    {
        get {
                if (store == null)
                {
                    store = new Gtk.NodeStore (typeof(MyTreeNode));
                    store.AddNode (new MyTreeNode ("The Beatles", "Yesterday"));
                    store.AddNode (new MyTreeNode ("Peter Gabriel", "In Your Eyes"));
                    store.AddNode (new MyTreeNode ("Rush", "Fly By Night"));
                }
            return store;
            }
    }

protected void OnButton1Clicked (object sender, EventArgs e)
{
    // Create a column with title Artist and bind its renderer to model column 0
    nodeview1.AppendColumn ("Artist", new Gtk.CellRendererText (), "text", 0);

    // Create a column with title 'Song Title' and bind its renderer to model column 1
    nodeview1.AppendColumn ("Song Title", new Gtk.CellRendererText (), "text", 1);
        nodeview1.ShowAll ();

    nodeview1.NodeStore=Store;

}

但是如何为 NodeView 的某些行着色(例如，“The Beatles” - “Yesterday”)？我尝试通过更改 NodeView 样式来做到这一点:背景、底色、前景和其他但它不起作用。

编辑:我刚刚意识到，我可以通过这种方式更改列的颜色:

protected void OnButton1Clicked (object sender, EventArgs e)
{
    // Create a column with title Artist and bind its renderer to model column 0
    nodeview1.AppendColumn ("Artist", new Gtk.CellRendererText (), "text", 0);



    // Create a column with title 'Song Title' and bind its renderer to model column 1
    nodeview1.AppendColumn ("Song Title", new Gtk.CellRendererText (), "text", 1);
        nodeview1.ShowAll ();

    nodeview1.NodeStore=Store;
    nodeview1.Columns[0].Cells[0].CellBackgroundGdk=new Gdk.Color(0,255,0);
}

但是我怎样才能改变特定单元格的颜色呢？

Answer 1

要在每行的基础上更改渲染属性，您有两种可能性

1. 在模型中定义属性，然后在创建单元格渲染器时引用它们；或
2. 编写您自己的 TreeCellDataFunc 并将其绑定(bind)到单元格渲染器，以确保在渲染之前更改其属性。

选项 1 更快，但限制您使用静态定义的值；当渲染不仅仅取决于一个变量并且涉及一些逻辑时，2 更好。我会告诉你如何做 1 并引用 Mono documentation 2.

如果你想改变前景色，你只需要在你的模型中添加一个新列:

[Gtk.TreeNode (ListOnly=true)]
public class MyTreeNode : Gtk.TreeNode 
{
    public MyTreeNode (string artist, string title, string color)
    {
        Artist = artist;
        Title = title; 
        Color = color;
    }

    [Gtk.TreeNodeValue (Column=0)]
    public string Artist;

    [Gtk.TreeNodeValue (Column=1)]
    public string Title;

    [Gtk.TreeNodeValue (Column=2)]
    public string Color;
}

将有效的 Gdk 颜色表示传递给行构造函数，例如“red”或“#ff0000”:

store.AddNode(new MyTreeNode("The Beatles", "Yesterday", "red"));
store.AddNode(new MyTreeNode("Peter Gabriel", "In Your Eyes", "black"));

然后当您构建 View 时，您只需将该模型列 (2) 绑定(bind)到单元格渲染器的“前景”属性:

nodeview1.AppendColumn("Artist", new Gtk.CellRendererText(), 
                       "text", 0, "foreground", 2);

nodeview1.AppendColumn("Song Title", new Gtk.CellRendererText(),
                       "text", 1, "foreground", 2);

就这些。