C#实现与新浪微博相同算法的字数统计函数，要的拿走。

微博剩余字数统计新浪官方算法的C#实现，要的朋友请保存。

参数text是正文内容。

isOutOfRange用来判断文字是否溢出，以此来控制发送按钮的可用状态。

public static string GetContentLengthString(string text, out bool isOutOfRange)
{
    text = text.Trim();
    text = Regex.Replace(text, "\r\n", "\n");
    int textLength = 0;
    if (text.Length > 0)
    {
        int min = 41, max = 140, urlLen = 20;
        var n = text;
        var r = Regex.Matches(text, @"http://[a-zA-Z0-9]+(\.[a-zA-Z0-9]+)+([-A-Z0-9a-z_$.+!*()/\\\,:;@&=?~#%]*)*");
        var total = 0;
        for (int m = 0, p = r.Count; m < p; m++)
        {
            var url = r[m].Value;
            var byteLen = url.Length + Regex.Matches(url, @"[^\x00-\x80]").Count;
            if (Regex.IsMatch(url, @"^(http://t.cn)"))
            {
                continue;
            }
            else if (Regex.IsMatch(url, @"^(http:\/\/)+(weibo.com|weibo.cn)"))
            {
                total += byteLen <= min ? byteLen : (byteLen <= max ? urlLen : (byteLen - max + urlLen));
            }
            else
            {
                total += byteLen <= max ? urlLen : (byteLen - max + urlLen);
            }
            n = n.Replace(url, "");
        }
        textLength = (int)Math.Ceiling((total + n.Length + Regex.Matches(n, @"[^\x00-\x80]").Count) / 2.00d);
    }

    int textRemainLength = 140 - textLength;
    string template = string.Empty;
    if (textRemainLength >= 0)
    {
        template = "还可以输入{0:N0}个字";
        isOutOfRange = false;
    }
    else
    {
        template = "已经超过了{0:N0}个字";

        isOutOfRange = true;
    }
    return string.Format(template, Math.Abs(textRemainLength));
}

执行效果