public SqlString Substring(int startIndex, int length)
{
if (startIndex < 0)
{
throw new ArgumentException("startIndex should be greater than or equal to 0", "startIndex");
}
if (length < 0)
{
throw new ArgumentException("length should be greater than or equal to 0", "length");
}
SqlStringBuilder builder = BuildSubstring(startIndex);
if (builder.Count == 0)
{
return(builder.ToSqlString());
}
int offset = 0;
int nextOffset = -1;
int count = int.MaxValue;
for (int i = 0; i < builder.Count; i++)
{
nextOffset = offset + LengthOfPart(builder[i]);
if (nextOffset < length)
{
offset = nextOffset;
continue;
}
else if (nextOffset >= length)
{
count = i + 1;
break;
}
}
while (builder.Count > count)
{
builder.RemoveAt(builder.Count - 1);
}
if (length < nextOffset)
{
string lastPart = (string)builder[builder.Count - 1];
builder[builder.Count - 1] = lastPart.Substring(0, length - offset);
}
SqlString result = builder.ToSqlString();
if (isCompacted)
{
result.SetCompacted();
}
return(result);
}
/// <summary>
/// Retrieves a substring from this instance. The substring starts at a specified character position.
/// </summary>
/// <param name="startIndex">The starting character position of a substring in this instance.</param>
/// <returns>
/// A new SqlString to the substring that begins at startIndex in this instance.
/// </returns>
/// <remarks>
/// If the startIndex is greater than the length of the SqlString then <see cref="SqlString.Empty" /> is returned.
/// </remarks>
public SqlString Substring(int startIndex)
{
if (startIndex < 0)
{
throw new ArgumentException("startIndex should be greater than or equal to 0", "startIndex");
}
SqlStringBuilder builder = BuildSubstring(startIndex);
if (builder.Count == 0)
{
return(Empty);
}
SqlString result = builder.ToSqlString();
if (isCompacted)
{
result.SetCompacted();
}
return(result);
}