Angular Passing FormData to WebAPI. Getting null RRS feed

  • Question

  • User956626884 posted
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    I am passing FormData object from Angular 7 to WebAPI but I getting a null

    Any help is appreciated. Thanks

    From typescript, i have

          if (event.target.files[0]) {
              this.blob = event.target.files[0];
    save() {
    let formDataDTO = new FormData();
            formDataDTO.append('file', this.blob, this.fileName);
    this.http.post<T>(this.url, JSON.stringify(formDataDTO), this.getHeaders())
          catchError(error => {

    In WebAPI,

            public HttpResponseMessage SaveInventoryAddOn([FromBody] HttpPostedFileBase form)
                var test = form; // form is always null
    //cannot access Request.Content.file
    // Request.Content.isFormData() is false
    // Request.Content.IsMimeMultipartContent() cannot be evaluated
    Wednesday, August 14, 2019 3:19 PM

All replies

  • User-474980206 posted

    the following code removes the file data from the post:

    this.http.post<T>(this.url, JSON.stringify(formDataDTO), this.getHeaders())

    you need to pass the actual FormData  object to the underlying fetch or XMLHTTPRequest object (don't know if http.post supports this). your other option is convert the blob to base64 string so that  it can be passed in a json object. then in the action it just a string parameter that you convert back to byte[]


    Wednesday, August 14, 2019 7:54 PM