how to inject multi-parameters within multi-part/form-data post when uploading file

[sum2000]

My question is the same one as somebody ask on stack 
overflow:http://stackoverflow.com/questions/30390380/how-to-pass-form-data-while-calling-api-using-jmeter.


But My server can’t handle correctly the request with parameter “filename” fill 
into “Paramters”.


And the server can process correctly request as following :
------WebKitFormBoundaryEqSCqTlGBdwaA7B1 Content-Disposition: form-data; 
name="multipartFile"; filename="validate.jpg" Content-Type: image/jpeg 
------WebKitFormBoundaryEqSCqTlGBdwaA7B1———




Yong Fu