Using Facebook SDK to Upload Screenshot in Unity

Question

I'm am trying to use Facebook SDK to Upload Screenshots to Facebook using FB.Feed() instead of FB.API() so that users can write a message to their post. I was able to get this to work on Unity Editor but when I try it on my Android, I get:

"This dialog has been passed a bad parameter.

API Error Code: 100
API Error Description: Invalid parameter
Error Message: picture URL is not properly formatted"

And here is the code I wrote:

var width = Screen.width;
var height = Screen.height;
var tex = new Texture2D(width, height, TextureFormat.RGB24, false);
// Read screen contents into the texture
tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
tex.Apply();
byte[] screenshot = tex.EncodeToPNG();
File.WriteAllBytes(Application.persistentDataPath + "/Screenshot.png", screenshot);

//Application.CaptureScreenshot(Application.persistentDataPath + "/Screenshot.png");
Debug.Log(Application.persistentDataPath + "/Screenshot.png");
Debug.Log("Does File Exist? " + File.Exists(Application.persistentDataPath + "/Screenshot.png"));
Debug.Log("File://" + Application.persistentDataPath + "/Screenshot.png");
FB.Feed(
    picture: "File://" + Application.persistentDataPath + "/Screenshot.png"
);

Answer 1

You can't upload image to facebook using FB.Feed() , picture parametr must be url in web.

To upload image you may use FB.API("me/photos") method

private void TakeScreenshot()
{
    var width = Screen.width;
    var height = Screen.height;
    var tex = new Texture2D(width, height, TextureFormat.RGB24, false);
    // Read screen contents into the texture
    tex.ReadPixels(new Rect(0, 0, width, height), 0, 0);
    tex.Apply();
    byte[] screenshot = tex.EncodeToPNG();

    WWWForm wwwForm = new WWWForm();
    wwwForm.AddBinaryData("image", screenshot, "screenshot.png");

    FB.API("me/photos", HttpMethod.POST, CallBack, wwwForm);
}