Search with SharePoint CSOM (portable) throws an exception

Question

I am trying to use SharePoint client framework to execute a search, using the portable dll's from a Windows app.

Using Fiddler I can see that my search is executed, and returns a JSON collection of metadata and search results. This is identical to the result from the non-portable CSOM.

When CSOM tries to map the result to it's data objects I get the following exception:

Unable to cast object of type 'System.Collections.Generic.Dictionary`2[System.String,System.Object]' to type 'Microsoft.SharePoint.Client.Search.Query.ResultTableCollection'.

This exception occurs inside CSOM (portable). Non-portable CSOM runs without exception, and returns the expected result.

The code I am running to get this exception is:

var query = new KeywordQuery(ctx);
query.QueryText = "something";
var executor = new SearchExecutor(ctx);
var results = executor.ExecuteQuery(query);
await ctx.ExecuteQueryAsync();

In the above, ctx is a ClientContext that has already been authenticated. Other requests, such as getting a specific list, works as expected.

I am referencing the following dll's from c:\Program Files\Common Files\microsoft shared\Web Server Extensions\16\ISAPI:

Microsoft.SharePoint.Client.Portable.dll
Microsoft.SharePoint.Client.Runtime.Portable.dll
Microsoft.SharePoint.Client.Runtime.WindowsStore.dll
Microsoft.SharePoint.Client.Search.Portable.dll

My question is.

How do I solve this, so that I can use CSOM to run search queries from a Windows Store app?

UPDATE: I added the following after authenticating the ClientContext:

ctx.ExecutingWebRequest += (s, e) =>
    e.WebRequest.Headers["Accept-Encoding"] = "gzip, deflate";

This solved the immediate problem, but introduced a new one. I am now getting a System.FormatException:

Not well formatted JSON stream.

Since the JSON from portable and non-portable CSOM is the same, there should not be a parsing error in one CSOM and not the other.

Santosha Epili Santosha Epili · Accepted Answer · 2015-07-10T11:07:27

What I can identify from your exception is that casting of execute query result creates problem here.

Use below code to cast execute query result

ResultTable rtSharePointSearchResult = new ResultTable();
KeywordQuery query = new KeywordQuery(clientContext);
query.QueryText = "Keywords";
query.TrimDuplicates = false;
SearchExecutor searchExecutor = new SearchExecutor(clientContext);
ClientResult<ResultTableCollection> results = searchExecutor.ExecuteQuery(query);
clientContext.ExecuteQuery();
rtSharePointSearchResult = results.Value[0];

Search with SharePoint CSOM (portable) throws an exception

2 Answers