Quick Cards Uri Mapper problem

Question

I'm trying to set up Search Extensibility on my app, but I keep getting an error message "QuickCardUriMapper.MapUri(System.Uri)': not all code paths return a value"
using System;
using System.Windows.Navigation;
using System.Net;
namespace Malaccaguide
public class QuickCardUriMapper : UriMapperBase
private static string TargetPageName = "LocationsPage.xaml";
private string tempUri;
public override Uri MapUri(Uri uri)
tempUri = uri.ToString();
// Parse URI when launched by from a quick card.
if (tempUri.Contains("/SearchExtras"))
// Decode all characters in the URI.
tempUri = HttpUtility.UrlDecode(tempUri);
// Create a new URI for place cards.
if (tempUri.Contains("Bing_Places"))
return GetPlaceCardUri(tempUri);
// Immediately return the URI when it isn’t related to Search extensibility.
return uri;
// Return a parsed Place Card URI.
private Uri GetPlaceCardUri(string uri)
// Extract parameter values from URI.
string PlaceNameValue = GetURIParameterValue("PlaceName=", uri);
string PlaceLatitudeValue = GetURIParameterValue("PlaceLatitude=", uri);
string PlaceLongitudeValue = GetURIParameterValue("PlaceLongitude=", uri);
string PlaceAddressValue = GetURIParameterValue("PlaceAddress=", uri);
string CategoryValue = GetURIParameterValue("Category=", uri);
// Create new URI.
string NewURI = String.Format("/{0}?PlaceName={1}&PlaceLatitude={2}&PlaceLongitude={3}&PlaceAddress={4}&Category={5}",
TargetPageName, PlaceNameValue, PlaceLatitudeValue, PlaceLongitudeValue, PlaceAddressValue, CategoryValue);
return new Uri(NewURI, UriKind.Relative);
// This method extracts the string values that correspond to URI parameters from a quick card.
private string GetURIParameterValue(string parameteridentifier, string uri)
string tempValue = "";
// If the parameter exists in the string, extract the corresponding parameter value.
if (uri.Contains(parameteridentifier))
string subUri;
// Extract the characters that contain and follow the parameter identifier.
subUri = uri.Substring(uri.LastIndexOf(parameteridentifier));
// Remove the parameter identifier from the substring.
subUri = subUri.Replace(parameteridentifier, "");
// Obtain the position of the next parameter in the substring.
int nextParameterPosition = FindNextParameter(subUri);
if (nextParameterPosition < int.MaxValue)
// Remove the characters that contain and follow the next parameter.
tempValue = subUri.Substring(0, nextParameterPosition);
else
// No more parameters follow in the string.
tempValue = subUri;
// Encode the parameter values to help prevent issues in the URI.
tempValue = HttpUtility.UrlEncode(tempValue);
return tempValue;
// Returns the string position of the next URI parameter, if applicable.
private int FindNextParameter(string subUri)
int lowestPosition = int.MaxValue;
int tempPosition;
tempPosition = subUri.IndexOf("&ProductName");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&Category");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&PlaceName");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("?PlaceName");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&PlaceLatitude");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&PlaceLongitude");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&PlaceAddress");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
tempPosition = subUri.IndexOf("&MovieName");
if ((tempPosition > -1) && (tempPosition < lowestPosition)) lowestPosition = tempPosition;
return lowestPosition;

Answer 1

Hello,you method MapUri does not return a value in every case:
This is your code:
tempUri = uri.ToString();
// Parse URI when launched by from a quick card.
if (tempUri.Contains("/SearchExtras"))
// Decode all characters in the URI.
tempUri = HttpUtility.UrlDecode(tempUri);
// Create a new URI for place cards.
if (tempUri.Contains("Bing_Places"))
return GetPlaceCardUri(tempUri);
// Immediately return the URI when it isn’t related to Search extensibility.
return uri;
} //END IF
And this is a better way to do it:
tempUri = uri.ToString();
// Parse URI when launched by from a quick card.
if (tempUri.Contains("/SearchExtras"))
// Decode all characters in the URI.
tempUri = HttpUtility.UrlDecode(tempUri);
// Create a new URI for place cards.
if (tempUri.Contains("Bing_Places"))
return GetPlaceCardUri(tempUri);
// Immediately return the URI when it isn’t related to Search extensibility.
return uri;
} //END IF
return null; //Return null or an empty uri when tempUri does not contain "/SearchExtras".
Note: You error is shown because you check for an string ("/SearchExtras") and than you return a value: "return uri". But what is when your string does not contains this string? Right, than the if-cluase will be ignored and the code reaches
its end (after "END IF"). And there it would not return a value.
I hope i was able to help you :)
© 2015 Thomas Roskop
Germany // Deutschland