CODEWITHSUNDEEP
c#winformsuser-controls
user3634308
user3634308

Reputation: 129

How to pass values to a user control in winforms c#

I have a winforms app that where I programmatically create a user control and pass values to it. When I run the program all the variables in the user control are null. I don't know what I'm doing wrong. When I look up similar programs it looks like I have the same code, but it's not working. Maybe someone on here can help.

Here is the main form code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Net;

namespace AddPanel
{
    public partial class Form1 : Form
    {

        public Form1()
        {

            InitializeComponent();

            DisplayImage();
        }


        private void DisplayImage()
        {

            FileStream fs = new FileStream("ntst.jpg", FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);

            cameraTable = (from x in db.CamTable1s
                           select x).ToList();

            test nt = new test();
            nt.Location = new System.Drawing.Point(33, 20);
            nt.Name = "test1";
            nt.usrID = "username";
            nt.IPadd = "ipaddress";
            nt.pswd = "password";
            nt.ws = fs;
            nt.Size = new System.Drawing.Size(408, 266);
            this.Controls.Add(nt);

        }    

    }
}

The user control code:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.IO;
using System.Net;

using AForge;
using AForge.Video;
using AForge.Controls;
using AForge.Video.DirectShow;

namespace AddPanel
{
    public partial class test : UserControl
    {
        public string IPadd { get; set; }
        public string usrID { get; set; }
        public string pswd { get; set; }
        public string filename { get; set; }
        public FileStream ws { get; set; }


        public test()
        {

            JPEGStream jpegSource1 = new JPEGStream("http://" + IPadd + "/jpg/image.jpg?resolution=320x240");
            jpegSource1.Login = usrID;
            jpegSource1.Password = pswd;
            jpegSource1.NewFrame += new NewFrameEventHandler(jpegSource1_NewFrame);
            //source1.VideoSourceError += new VideoSourceErrorEventHandler(source1_VideoSourceError);
            jpegSource1.VideoSourceError += new VideoSourceErrorEventHandler(jpegSource1_VideoSourceError);
            Player1.VideoSource = jpegSource1;

            InitializeComponent();
        }

        void jpegSource1_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            Bitmap image = new Bitmap(eventArgs.Frame, 320, 240);

            image.Save(ws, System.Drawing.Imaging.ImageFormat.Bmp);
        }

        void jpegSource1_VideoSourceError(object sender, VideoSourceErrorEventArgs eventArgs)
        {
            //Error handler
            Debug.WriteLine(eventArgs.Description);

            Bitmap ErPic = new Bitmap(320, 240);
            using (var g = Graphics.FromImage(ErPic))
            {
                using (var arialFontLarge = new Font("Arial", 15))
                {
                    g.DrawString("Camera Offline", arialFontLarge, Brushes.White, 75, 100);
                }

            }
            ErPic.Save(ws, ImageFormat.Bmp);
        }

        private void StartBut_Click(object sender, EventArgs e)
        {
            Player1.VideoSource.Start();
        }

        private void StopBut_Click(object sender, EventArgs e)
        {
            Player1.VideoSource.Stop();
            ws.Close();
        }
    }
}

Upvotes: 2

Views: 8631

Answers (2)

user3634308
user3634308

Reputation: 129

The problem was that my understanding of using variables between forms was wrong.

I should have put 

public string IPadd { get; set; }
public string usrID { get; set; }
public string pswd { get; set; }
public string filename { get; set; }
public FileStream ws { get; set; }

in Form1 and then accessed them in test. Like this: Form1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.IO;
using System.Data.SqlClient;
using System.Diagnostics;
using System.Net;

using AForge.Video;
using AForge.Controls;
using AForge.Video.DirectShow;

namespace AddPanel
{
    public partial class Form1 : Form
    {
        private string iPadd;
        public string IPadd
        {
            get { return iPadd;}
            set
            {
                iPadd = value;

            }
        }

        private string usrID;
        public string UsrID
            {
            get { return usrID; }
            set
            {
                usrID = value;
            }
        }

        private string Pswd;
        public string pswd
        { 
            get{return Pswd;}
            set
            {
                Pswd = value;
            }
        }
        private string Filename;
        public string filename
        {
            get { return Filename; }
            set
            {
                Filename = value;
            }
         }

        public Form1()
        {


            InitializeComponent();


            DisplayImage();
        }


        private void DisplayImage()
        {



            FileStream fs = new FileStream(filename, FileMode.OpenOrCreate, FileAccess.ReadWrite, FileShare.ReadWrite);


            UsrID = "webservice";
            IPadd = "10.108.212.100";
            pswd = "E4emw@tch!ngU";
            WS = fs;

            test nt = new test();
            nt.Location = new System.Drawing.Point(33, h);
            nt.Name = "test1";
            nt.Size = new System.Drawing.Size(408, 266);
            this.Controls.Add(nt);

        } 

    }
}

Then I can access those variables in test like this:

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Drawing;
using System.Drawing.Imaging;
using System.Data;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Diagnostics;
using System.IO;
using System.Net;

using AForge;
using AForge.Video;
using AForge.Controls;
using AForge.Video.DirectShow;

namespace AddPanel
{
    public partial class test : UserControl
    {    

        public test()
        {
            Form1 f1 = new Form1();
            JPEGStream jpegSource1 = new JPEGStream("http://" + f1.IPadd + "/jpg/image.jpg?resolution=320x240");
            jpegSource1.Login = f1.UsrID;
            jpegSource1.Password = f1.pswd;
            jpegSource1.NewFrame += new NewFrameEventHandler(jpegSource1_NewFrame);
            //source1.VideoSourceError += new VideoSourceErrorEventHandler(source1_VideoSourceError);
            jpegSource1.VideoSourceError += new VideoSourceErrorEventHandler(jpegSource1_VideoSourceError);
            Player1.VideoSource = jpegSource1;

            InitializeComponent();
        }

        void jpegSource1_NewFrame(object sender, NewFrameEventArgs eventArgs)
        {
            Bitmap image = new Bitmap(eventArgs.Frame, 320, 240);

            image.Save(ws, System.Drawing.Imaging.ImageFormat.Bmp);
        }

        void jpegSource1_VideoSourceError(object sender, VideoSourceErrorEventArgs eventArgs)
        {
            //Error handler
            Debug.WriteLine(eventArgs.Description);

            Bitmap ErPic = new Bitmap(320, 240);
            using (var g = Graphics.FromImage(ErPic))
            {
                using (var arialFontLarge = new Font("Arial", 15))
                {
                    g.DrawString("Camera Offline", arialFontLarge, Brushes.White, 75, 100);
                }

            }
            ErPic.Save(ws, ImageFormat.Bmp);
        }

        private void StartBut_Click(object sender, EventArgs e)
        {
            Player1.VideoSource.Start();
        }

        private void StopBut_Click(object sender, EventArgs e)
        {
            Player1.VideoSource.Stop();
            ws.Close();
        }
    }
}

Upvotes: 0

Mark Hall
Mark Hall

Reputation: 54532

Your UserControls constructor gets run when you new up your UserControl, you are setting your values after the fact. I would personally either create a constructor that you can pass in your initial settings or make a method that you execute to initialize it after you populate your values.

Something like this:

public partial class test : UserControl
{
    public string IPadd { get; set; }
    public string usrID { get; set; }
    public string pswd { get; set; }
    public string filename { get; set; }
    public FileStream ws { get; set; }

    public test()
    {
        InitializeComponent();
    }
    public test(string Ip, string Id, string Pass, string file, FileStream stream )
    {
        InitializeComponent();

        IPadd = Ip;
        usrID = Id;
        pswd = Pass;
        filename = file;
        ws = stream;

        JPEGStream jpegSource1 = new JPEGStream("http://" + IPadd + "/jpg/image.jpg?resolution=320x240");
        jpegSource1.Login = usrID;
        jpegSource1.Password = pswd;
        jpegSource1.NewFrame += new NewFrameEventHandler(jpegSource1_NewFrame);
        source1.VideoSourceError += new VideoSourceErrorEventHandler(source1_VideoSourceError);
        pegSource1.VideoSourceError += new VideoSourceErrorEventHandler(jpegSource1_VideoSourceError);
        Player1.VideoSource = jpegSource1;

    }
}

Upvotes: 3

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