diff --git a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
index c0da6aebb1..1eef7176fe 100644
--- a/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
+++ b/ICSharpCode.NRefactory.CSharp/Completion/CSharpCompletionEngineBase.cs
@@ -146,8 +146,15 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			return false;
 		}
 		
-		public int GetCurrentParameterIndex (int triggerOffset, int endOffset)
+		public int GetCurrentParameterIndex(int triggerOffset, int endOffset)
 		{
+			List<string> list;
+			return  GetCurrentParameterIndex (triggerOffset, endOffset, out list);
+		}
+
+		public int GetCurrentParameterIndex (int triggerOffset, int endOffset, out List<string> usedNamedParameters)
+		{
+			usedNamedParameters =new List<string> ();
 			char lastChar = document.GetCharAt (endOffset - 1);
 			if (lastChar == '(' || lastChar == '<') { 
 				return 0;
@@ -155,134 +162,145 @@ namespace ICSharpCode.NRefactory.CSharp.Completion
 			var parameter = new Stack<int> ();
 			var bracketStack = new Stack<Stack<int>> ();
 			bool inSingleComment = false, inString = false, inVerbatimString = false, inChar = false, inMultiLineComment = false;
+			var word = new StringBuilder ();
 			for (int i = triggerOffset; i < endOffset; i++) {
 				char ch = document.GetCharAt (i);
 				char nextCh = i + 1 < document.TextLength ? document.GetCharAt (i + 1) : '\0';
+				if (ch == ':') {
+					usedNamedParameters.Add (word.ToString ());
+					word.Length = 0;
+				} else if (char.IsLetterOrDigit (ch) || ch =='_') {
+					word.Append (ch);
+				} else if (char.IsWhiteSpace (ch)) {
+
+				} else {
+					word.Length = 0;
+				}
 				switch (ch) {
-				case '{':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
-						break;
-					}
-					bracketStack.Push (parameter);
-					parameter = new Stack<int> ();
-					break;
-				case '[':
-				case '(':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '{':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						bracketStack.Push (parameter);
+						parameter = new Stack<int> ();
 						break;
-					}
-					parameter.Push (0);
-					break;
-				case '}':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '[':
+					case '(':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						parameter.Push (0);
 						break;
-					}
-					if (bracketStack.Count > 0) {
-						parameter = bracketStack.Pop ();
-					} else {
-						return -1;
-					}
-					break;
-				case ']':
-				case ')':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '}':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						if (bracketStack.Count > 0) {
+							parameter = bracketStack.Pop ();
+						} else {
+							return -1;
+						}
 						break;
-					}
-					if (parameter.Count > 0) {
-						parameter.Pop ();
-					} else {
-						return -1;
-					}
-					break;
-				case '<':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case ']':
+					case ')':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						if (parameter.Count > 0) {
+							parameter.Pop ();
+						} else {
+							return -1;
+						}
 						break;
-					}
-					parameter.Push (0);
-					break;
-				case '=':
-					if (nextCh == '>') {
-						i++;
-						continue;
-					}
-					break;
-				case '>':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '<':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						parameter.Push (0);
 						break;
-					}
-					if (parameter.Count > 0) {
-						parameter.Pop ();
-					}
-					break;
-				case ',':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '=':
+						if (nextCh == '>') {
+							i++;
+							continue;
+						}
 						break;
-					}
-					if (parameter.Count > 0) {
-						parameter.Push (parameter.Pop () + 1);
-					}
-					break;
-				case '/':
-					if (inString || inChar || inVerbatimString) {
+					case '>':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						if (parameter.Count > 0) {
+							parameter.Pop ();
+						}
 						break;
-					}
-					if (nextCh == '/') {
-						i++;
-						inSingleComment = true;
-					}
-					if (nextCh == '*') {
-						inMultiLineComment = true;
-					}
-					break;
-				case '*':
-					if (inString || inChar || inVerbatimString || inSingleComment) {
+					case ',':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
+						if (parameter.Count > 0) {
+							parameter.Push (parameter.Pop () + 1);
+						}
 						break;
-					}
-					if (nextCh == '/') {
-						i++;
-						inMultiLineComment = false;
-					}
-					break;
-				case '@':
-					if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+					case '/':
+						if (inString || inChar || inVerbatimString) {
+							break;
+						}
+						if (nextCh == '/') {
+							i++;
+							inSingleComment = true;
+						}
+						if (nextCh == '*') {
+							inMultiLineComment = true;
+						}
 						break;
-					}
-					if (nextCh == '"') {
-						i++;
-						inVerbatimString = true;
-					}
-					break;
-				case '\n':
-				case '\r':
-					inSingleComment = false;
-					inString = false;
-					inChar = false;
-					break;
-				case '\\':
-					if (inString || inChar) {
-						i++;
-					}
-					break;
-				case '"':
-					if (inSingleComment || inMultiLineComment || inChar) {
+					case '*':
+						if (inString || inChar || inVerbatimString || inSingleComment) {
+							break;
+						}
+						if (nextCh == '/') {
+							i++;
+							inMultiLineComment = false;
+						}
 						break;
-					}
-					if (inVerbatimString) {
+					case '@':
+						if (inString || inChar || inVerbatimString || inSingleComment || inMultiLineComment) {
+							break;
+						}
 						if (nextCh == '"') {
 							i++;
+							inVerbatimString = true;
+						}
+						break;
+					case '\n':
+					case '\r':
+						inSingleComment = false;
+						inString = false;
+						inChar = false;
+						break;
+					case '\\':
+						if (inString || inChar) {
+							i++;
+						}
+						break;
+					case '"':
+						if (inSingleComment || inMultiLineComment || inChar) {
 							break;
 						}
-						inVerbatimString = false;
+						if (inVerbatimString) {
+							if (nextCh == '"') {
+								i++;
+								break;
+							}
+							inVerbatimString = false;
+							break;
+						}
+						inString = !inString;
 						break;
-					}
-					inString = !inString;
-					break;
-				case '\'':
-					if (inSingleComment || inMultiLineComment || inString || inVerbatimString) {
+					case '\'':
+						if (inSingleComment || inMultiLineComment || inString || inVerbatimString) {
+							break;
+						}
+						inChar = !inChar;
 						break;
-					}
-					inChar = !inChar;
-					break;
 				}
 			}
 			if (parameter.Count == 0 || bracketStack.Count > 0) {