How to Get value from another Form in C#

By Tan Lee Published on Jul 25, 2017 10.25K

To get a value from another form in a C# Windows Forms application, you typically use properties or methods in the target form to expose the data you need.

Open your Visual Studio, then click New Project, then select Visual C# on the left, then Windows and then select Windows Forms Application. Name your project "GetValueFromAnotherForm" and then click OK

Design your form as shown below.

Form1

c# get value from another form

This form will contain Add and Edit buttons to open the second form (frmAddEditStudent) and retrieve a value from it.

frmAddEditStudent

get value from another form in c#

Create a student class to map data

public class Student
{
    public string ID { get; set; }
    public string FullName { get; set; }
}

Add code to handle your form as shown below.

Form1

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GetValueFromAnotherForm
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void btnAdd_Click(object sender, EventArgs e)
        {
            //Add a student to binding source
            using(frmAddEditStudent frm = new frmAddEditStudent() { StudentInfo = new Student() })
            {
                if (frm.ShowDialog() == DialogResult.OK)
                    studentBindingSource.Add(frm.StudentInfo);
            }
        }

        private void btnEdit_Click(object sender, EventArgs e)
        {
            Student obj = studentBindingSource.Current as Student;
            if(obj != null)
            {
                using(frmAddEditStudent frm = new frmAddEditStudent() { StudentInfo = obj })
                {
                    if(frm.ShowDialog() == DialogResult.OK)
                    {
                        studentBindingSource.EndEdit();
                        btnEdit.Focus();
                    }
                }
            }
        }
    }
}

frmAddEditStudent

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace GetValueFromAnotherForm
{
    public partial class frmAddEditStudent : Form
    {
        public Student StudentInfo { get; set; }
        public frmAddEditStudent()
        {
            InitializeComponent();
        }

        private void frmAddEditStudent_Load(object sender, EventArgs e)
        {
            //Init data
            if (StudentInfo != null)
            {
                txtStudentID.Text = StudentInfo.ID;
                txtFullName.Text = StudentInfo.FullName;
            }
        }

        private void btnOK_Click(object sender, EventArgs e)
        {
            StudentInfo.ID = txtStudentID.Text;
            StudentInfo.FullName = txtFullName.Text;
        }
    }
}

By using properties and the modal dialog pattern, you can easily pass values between forms in a C# Windows Forms application.

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