CODEWITHSUNDEEP
c#.netwinforms
Royce
Royce

Reputation: 189

Drawing shapes and saving file into text, encoding and decoding

I need assistance with saving drawn shapes on a winform using graphics from a list I created that store the shape type and the information for the shape the user draws, into a text file that encodes it into UTF8 (or to their choosing).

My problem is after saving the "drawing", which has shape type lines, rectangle, etc. as a text file. How do I open it in the winform application and parse the numbers and re-create the shape on the winform using graphics and paint event?

What I currently have in code, is the user draws shapes onto a graphic handled by mouse events, and then it goes into a list. The user also selects the encoding type for the text file (like Encoding.ASCII, etc.) Then I have a save menu where the user saves the file into a location. There is also a clear button to clear the drawings and such. Then I can't figure out how to open the text file to re-create that saved drawing that was cleared.

I looked at the msdn API about creating my own format for the encoding, but I'm confused on how to do it.

What I thought about doing was checking what encoding the user saved it, and then choosing the appropriate custom format to re-create the shape on the winform graphic.

Any ideas? Thank you.

EDIT: The code I'm using for saving the text file:

                using (BinaryWriter save_bin = new BinaryWriter(File.Open(save_fd.FileName, FileMode.OpenOrCreate), Encoding.UTF8))
                {
                    foreach (Shape a in shapeList)
                    {
                        save_bin.Write(a.ToString());
                    }
                    save_bin.Close();
                }

I think I should not use ToString(), but something else to write.

Upvotes: 0

Views: 964

Answers (2)

Anthony Dekimpe
Anthony Dekimpe

Reputation: 367

More info on serialization:

Firstly, your classes should contain the [Serializable] attribute

[Serializable]
public class Example()
{

}

Then you have the ability to save it like this:

Example obj = new Example();

// Set properties of the 'Example' object

IFormatter formatter = new BinaryFormatter(); // Save the file
Stream stream = new FileStream("MyFile.bin", FileMode.Create, FileAccess.Write, FileShare.None);
formatter.Serialize(stream, obj);
stream.Close();

Restoring the file back to your class can be done like this:

IFormatter formatter = new BinaryFormatter();
Stream stream = new FileStream("MyFile.bin", FileMode.Open, FileAccess.Read, FileShare.Read);
MyObject obj = (MyObject) formatter.Deserialize(stream);
stream.Close();

Source: https://msdn.microsoft.com/en-us/library/4abbf6k0(v=vs.110).aspx

Upvotes: 1

Aydin
Aydin

Reputation: 15294

Do this, from NuGet, download JSON.Net 

PM> Install-Package Newtonsoft.Json

Next, copy this code

string jsonStateOfShape = JsonConvert.SerializeObject(shapeList);
using (FileStream stream = new FileStream("shapes.json", FileMode.Create))
using (StreamWriter writer = new StreamWriter(stream))
{
    writer.Write(jsonStateOfShape);
}


// To re open
string reopenedState = string.Empty;
using (FileStream stream = new FileStream("shapes.json", FileMode.Open))
using (StreamReader reader = new StreamReader(stream))
{
    reopenedState = reader.ReadToEnd();
}
var shapes = JsonConvert.DeserializeObject<List<Shape>>(reopenedState);

shapes.ForEach(shapeList.Add);

// dont try to replace shapeList directly, referencing issues...

Upvotes: 1

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