c# - windows窗体中的自定义列表框（或）自定义面板

Question

我试图创建一个 facebook 应用程序，显示时间线和其他消息，我需要自定义列表框，显示发件人的图像，以及在单个列表项中以粗体显示发件人姓名作为标题和消息内容。

我不知道自定义面板，如何使用它...

像这样...

提前致谢....

Answer 1

我试着写这个让你看看自定义面板的样子 (:)，这不是一个完整的列表控件，需要更多扩展，但它满足你的大部分需求。我认为这对您来说是一个很好的示例，可以帮助您入门，以便您可以轻松构建自己的自定义控件：

public class ListPanel : Panel
{
    public ListPanel()
    {
        AutoScroll = true;
        BorderStyle = BorderStyle.FixedSingle;
    }
    private List<ListPanelItem> items = new List<ListPanelItem>();
    public void AddItem(ListPanelItem item)
    {
        item.Index = items.Count;
        items.Add(item);            
        Controls.Add(item);
        item.BringToFront();
        item.Click += ItemClicked;
    }
    public int SelectedIndex { get; set; }
    public ListPanelItem SelectedItem { get; set; }
    private void ItemClicked(object sender, EventArgs e)
    {
        ListPanelItem item = sender as ListPanelItem;
        if (SelectedItem != null) SelectedItem.Selected = false;
        SelectedItem = item;
        SelectedIndex = item.Index;
        item.Selected = true;
        if (ItemClick != null) ItemClick(this, new ItemClickEventArgs() {Item = item});
    }
    public class ItemClickEventArgs : EventArgs
    {
        public ListPanelItem Item { get; set; }
    }
    public delegate void ItemClickEventHandler(object sender, ItemClickEventArgs e);
    public event ItemClickEventHandler ItemClick;
}
//Here is the class for ListPanelItem
public class ListPanelItem : Panel
{
    public ListPanelItem()
    {
        DoubleBuffered = true;
        ImageSize = new Size(100, 100);
        CaptionColor = Color.Blue;
        ContentColor = Color.Green;
        CaptionFont = new Font(Font.FontFamily, 13, FontStyle.Bold | FontStyle.Underline);
        ContentFont = new Font(Font.FontFamily, 10, FontStyle.Regular);
        Dock = DockStyle.Top;
        SelectedColor = Color.Orange;
        HoverColor = Color.Yellow;
        Caption = "";
        Content = "";
    }
    private bool selected;
    public Size ImageSize { get; set; }
    public Image Image { get; set; }
    public string Caption { get; set; }
    public string Content { get; set; }
    public Color CaptionColor { get; set; }
    public Color ContentColor { get; set; }
    public Font CaptionFont { get; set; }
    public Font ContentFont { get; set; }
    public int Index { get; set; }
    public bool Selected
    {
        get { return selected; }
        set
        {
            selected = value;
            Invalidate();
        }
    }
    public Color SelectedColor { get; set; }
    public Color HoverColor { get; set; }        
    protected override void OnPaint(PaintEventArgs e)
    {
        Color color1 = mouseOver ? Color.FromArgb(0, HoverColor) : Color.FromArgb(0, SelectedColor);
        Color color2 = mouseOver ? HoverColor : SelectedColor;
        Rectangle actualRect = new Rectangle(ClientRectangle.Left, ClientRectangle.Top, ClientRectangle.Width, ClientRectangle.Height - 2);
        using (System.Drawing.Drawing2D.LinearGradientBrush brush = new System.Drawing.Drawing2D.LinearGradientBrush(ClientRectangle, color1, color2, 90))
        {                                
            if (mouseOver)
            {                                        
                e.Graphics.FillRectangle(brush, actualRect);
            }
            else if (Selected)
            {
                e.Graphics.FillRectangle(brush, actualRect);
            }
        }
        if (Image != null)
        {
            e.Graphics.DrawImage(Image, new Rectangle(new Point(5, 5), ImageSize));
        }
        //Draw caption
        StringFormat sf = new StringFormat() { LineAlignment = StringAlignment.Center};            
        e.Graphics.DrawString(Caption, CaptionFont, new SolidBrush(CaptionColor), new RectangleF(ImageSize.Width + 10, 5, Width - ImageSize.Width - 10, CaptionFont.SizeInPoints * 1.5f), sf);
        //Draw content
        int textWidth = Width - ImageSize.Width - 10;
        SizeF textSize = e.Graphics.MeasureString(Content, ContentFont);
        float textHeight = (textSize.Width / textWidth) * textSize.Height + textSize.Height;
        int dynamicHeight = (int)(CaptionFont.SizeInPoints * 1.5) + (int)textHeight + 1;
        if (Height != dynamicHeight)
        {
            Height = dynamicHeight > ImageSize.Height + 10 ? dynamicHeight : ImageSize.Height + 10;
        }
        e.Graphics.DrawString(Content, ContentFont, new SolidBrush(ContentColor), new RectangleF(ImageSize.Width + 10, CaptionFont.SizeInPoints * 1.5f + 5, Width - ImageSize.Width - 10, textHeight));
        e.Graphics.DrawLine(Pens.Silver, new Point(ClientRectangle.Left, ClientRectangle.Bottom-1), new Point(ClientRectangle.Right, ClientRectangle.Bottom-1));
        base.OnPaint(e);
    }        
    bool mouseOver;
    protected override void OnMouseEnter(EventArgs e)
    {
        mouseOver = true;
        base.OnMouseEnter(e);
        Invalidate();
    }
    protected override void OnMouseLeave(EventArgs e)
    {
        mouseOver = false;
        base.OnMouseLeave(e);
        Invalidate();
    }
}

代码还没有优化，比如一些代码可以在OnPaint方法之外完成，但为了简单起见，我把它保留在那里。

这是我的列表控件（或列表框）的外观：