Xamarin.Forms 标签中的超链接 - 索引超出范围

Question

如果它仅显示 1 个超链接，则此方法可以正常工作，但出现多个超链接呈现的问题并出现以下问题

--------- 堆栈跟踪 --------- 在 System.String.Substring (System.Int32 startIndex, System.Int32 长度) [0x0004c] in :0 at MPI.UI.Mobile.Converter.HtmlLabelConverter.ProcessString (System.String rawText) [0x0004b] in :0 at MPI.UI.Mobile.Converter.HtmlLabelConverter.Convert (System.Object 值，System.Type 目标类型，System.Object 参数， System.Globalization.CultureInfo 文化）[0x00008] in :0 at Xamarin.Forms.Binding.GetSourceValue（System.Object 值，System.Type targetPropertyType) [0x0001b] 在 :0 在 Xamarin.Forms.BindingExpression.ApplyCore (System.Object sourceObject，Xamarin.Forms.BindableObject 目标， Xamarin.Forms.BindableProperty 属性，System.Boolean fromTarget） [0x001ce] 在 :0 处 Xamarin.Forms.BindingExpression.Apply（System.Boolean fromTarget） [0x0003e] 在 :0 处 Xamarin.Forms.BindingExpression+BindingExpressionPart.b__49_0 () [0x00000] 在 :0 处 Java.Lang.Thread+RunnableImplementor.Run () [0x00008] in :0 at Java.Lang.IRunnableInvoker.n_Run (System.IntPtr jnienv, System.IntPtr native__this) [0x00009] in :0 at (wrapper dynamic-method) System.Object.18(intptr,intptr) ------------------------------- --------- 消息 --------- 索引和长度必须引用字符串中的位置。参数名称：长度 - - - - - - - - - - - - - - - - - - - - - 资源 - - - - - mscorlib ----------

public IList<StringSection> ProcessString(string rawText)
{
    const string spanPattern = @"(<a.*?>.*?</a>)";

    MatchCollection collection = Regex.Matches(rawText, spanPattern, RegexOptions.Singleline);

    var sections = new List<StringSection>();

    var lastIndex = 0;

    foreach (Match item in collection)
    {
       sections.Add(new StringSection() { Text = rawText.Substring(lastIndex, item.Index) }); <!--Here the issue occurs -->
        lastIndex += item.Index + item.Length;  <!--Here the issue occurs -->

        // Get HTML href 
        var html = new StringSection()
        {
            Link = Regex.Match(item.Value, "(?<=href=\\\")[\\S]+(?=\\\")").Value,
            Text = Regex.Replace(item.Value, "<.*?>", string.Empty)
        };

        sections.Add(html);
    }

    sections.Add(new StringSection() { Text = rawText.Substring(lastIndex) });  <!--Here the issue occurs -->

    return sections;
}

public class StringSection
{
    public string Text { get; set; }
    public string Link { get; set; }
}

Answer 1

我已经解决了这个问题，rawText.Substring 索引超出范围..

public IList<StringSection> ProcessString(string rawText)
        {
            try
            {
                const string spanPattern = @"(<a.*?>.*?</a>)";

                MatchCollection collection = Regex.Matches(rawText, spanPattern, RegexOptions.Singleline);

                var sections = new List<StringSection>();

                int lastIndex = 0;
                int lastLinkIndex = 0;

                foreach (Match item in collection)
                {
                    var foundText = item.Value;
                    var currentIndexText = rawText.Substring(lastIndex, (item.Index - lastIndex));
                    sections.Add(new StringSection() { Text = currentIndexText });
                    lastIndex += item.Index + item.Length;
                    lastLinkIndex = item.Index + item.Length;
                    // Get HTML href 
                    var html = new StringSection()
                    {
                        Link = Regex.Match(item.Value, "(?<=href=\\\")[\\S]+(?=\\\")").Value,
                        Text = Regex.Replace(item.Value, "<.*?>", string.Empty)
                    };

                    sections.Add(html);
                }

                sections.Add(new StringSection() { Text = rawText.Substring(lastLinkIndex) });

                return sections;
            }
            catch (Exception ex)
            {
                throw ex;
            }
        }