winform 动态截断或者补全文字宽度
使用 TabControl 时,发现它的选项卡宽度会随文字长度变化,我自己做了一个浏览器,发现很难看,于是写了个算法,对文字长度进行填充或截断,效果很不错:
![](https://img2024.cnblogs.com/blog/65667/202407/65667-20240716133153260-848786538.png)
![](https://img2024.cnblogs.com/blog/65667/202407/65667-20240716133153260-848786538.png)
调用代码:
using (var g = tabs.CreateGraphics()) { tabPage.Text = " " + PadAndEllipsis(g, tabs.Font, title, 150) + " " ; }
核心函数:
/// <summary> /// 长度不够用空格前后填充,长度超过则截断并添加... /// </summary> /// <param name="g"></param> /// <param name="font"></param> /// <param name="str"></param> /// <param name="maxWith"></param> /// <returns></returns> string PadAndEllipsis(Graphics g, Font font, string str, int maxWith) { Func<string, float> getActualWidth = delegate (string text) { return g.MeasureString("|" + text + "|", font).Width - g.MeasureString("||", font).Width; }; var originalWidth = getActualWidth(str); var expectedStr = str; //字符串增加空格使它突破宽度 if (originalWidth < maxWith) { const string fillstr = " "; //快速填充使其超过标准宽度 do { expectedStr = expectedStr + string.Concat(Enumerable.Repeat(fillstr, expectedStr.Length)); } while (getActualWidth(expectedStr) < maxWith); //使用二分查找法 var start = 0; var end = expectedStr.Length; while (start < end) { var pos = start + (int)Math.Ceiling(((double)end - start) / 2); if (getActualWidth(expectedStr.Substring(0, pos)) > maxWith) { if (end == pos) break; end = pos; } else { if (start == pos) break; start = pos; } } var padding = string.Concat(Enumerable.Repeat(fillstr, (end - str.Length) / 2)); var result = padding + str + padding; var w = getActualWidth(result); return result; } else { const string suffixstr = "..."; //使用二分查找法 var start = 0; var end = expectedStr.Length; while (start < end) { var pos = start + (int)Math.Ceiling(((double)end - start) / 2); if (getActualWidth(expectedStr.Substring(0, pos) + suffixstr) > maxWith) { if (end == pos) break; end = pos; } else { if (start == pos) break; start = pos; } } var result = str.Substring(0, start) + suffixstr; return result; } }
桂棹兮兰桨,击空明兮溯流光。