System.ArgumentOutOfRangeException Parameter name: chunkLength at System.Text.StringBuilder.ToString()

问题

I have got below exception in a log file.

System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: chunkLength at System.Text.StringBuilder.ToString()

I believe this is because of string Builder which is not a thread safe. But I am stumbled on how to make my string builder to thread safe in below recursive function.

public static class StringExtensions
{
    /// <summary>
    /// The log key builder
    /// </summary>
    private static StringBuilder logKeyBuilder;

    public static string ConcatLogKeyWithExceptionMessage<T>(this T entity, string configuredLogKeys, bool logOnlySingleKey, string exceptionMessage, bool firstInvocation = true) where T : class
    {
        logKeyBuilder = logKeyBuilder ?? new StringBuilder();

        if (entity != null)
        {
            var objType = entity.GetType();
            var properties = objType.GetProperties();
            foreach (var property in properties)
            {
                var propValue = property.GetValue(entity, null);
                var elems = propValue as IList;
                if (elems != null)
                {
                    foreach (var item in elems)
                    {
                        {
                            ConcatLogKeyWithExceptionMessage(item, configuredLogKeys, logOnlySingleKey, exceptionMessage, false);
                        }
                    }
                }
                else
                {
                    // This will not cut-off System.Collections because of the first check
                    if (property.PropertyType.Assembly == objType.Assembly)
                    {
                        ConcatLogKeyWithExceptionMessage(propValue, configuredLogKeys, logOnlySingleKey, exceptionMessage, false);
                    }
                    else
                    {
                        configuredKeysArray = configuredKeysArray ?? (!string.IsNullOrEmpty(configuredLogKeys) ? configuredLogKeys.Split(',') : new string[0]);

                        foreach (var configLogKey in configuredKeysArray)
                        {
                            if (string.Compare(configLogKey.Trim(), property.Name.Trim(), StringComparison.OrdinalIgnoreCase) == 0)
                            {
                                configuredKeysArray = configuredKeysArray.Where(x => x != configLogKey).ToArray();
                                logKeyBuilder.Append(property.Name);
                                logKeyBuilder.Append(" ");
                                logKeyBuilder.Append("-");
                                logKeyBuilder.Append(" ");
                                logKeyBuilder.Append(property.GetValue(entity));
                                logKeyBuilder.Append(" ");
                                if (logOnlySingleKey)
                                {
                                    break;
                                }
                            }
                        }
                    }
                }
            }
        }

        logKeyBuilder = firstInvocation ? logKeyBuilder.Append(exceptionMessage) : logKeyBuilder;
        return logKeyBuilder.ToString();
    }
}

回答1:

Using lock:

private static object lockObject = new object();
public static string ConcatLogKeyWithExceptionMessage<T>(this T entity, string configuredLogKeys, bool logOnlySingleKey, string exceptionMessage, bool firstInvocation = true) where T : class
{
    lock(lockObject )
    {
        // rest of your code here
    }
}

Or move your static field to be a local variable inside the method.

来源：https://stackoverflow.com/questions/38564486/system-argumentoutofrangeexception-parameter-name-chunklength-at-system-text-st

标签

multithreading

stringbuilder