How to add numbers recursively in form1 label from form2?

Question

How to add numbers recursively in form1 label which are entered from form2 textbox? For every time I enter the value in form2, it should add to the previous value which was displayed in form1 label.

Rajanikant Hawaldar · Answer

Find the attached zip file, fixed error and validated

Rajanikant Hawaldar · Answer

Simple instead of this line this.label2.Text += str; Use below code this.label2.Text = Convert. ToInt32(string.IsNullOrWhiteSpace( this.label2.Text) ? 0 : Convert.ToInt32(this.label2.Text)) + Convert.ToInt32(str);

Amit Mohanty · Answer

Hey replace the below code in your form1. int totalValue = 0; private void ObjForm2_EventPassData( string str) { totalValue += int .Parse(str); this .label2.Text = totalValue.ToString(); }

Rajanikant Hawaldar · Answer

Hi Kishore, its similer to one your previous thread,you need to use + symbol find it out in this code i have added with orange background color, for you to fix your issue, //Form1 code 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 PassForm2TextboxDataTOForm1Label { public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click( object sender, EventArgs e) { Form2 objForm2 = new Form2(); objForm2.EventPassData += ObjForm2_EventPassData; objForm2.Show(); } private void ObjForm2_EventPassData( string str) { this .label2.Text + = str; } } } //Form2 code 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 PassForm2TextboxDataTOForm1Label { public partial class Form2 : Form { public delegate void PassData( string str); public event PassData EventPassData; public Form2() { InitializeComponent(); } private void button1_Click( object sender, EventArgs e) { EventPassData(textBox1.Text); } } }

Rajanikant Hawaldar · Answer

Use below code in form 2 to allow to enter only numbers because if you enter words or symbols then it will throw error so add this below event to text box private void textBox1_KeyPress(object sender, KeyPressEventArgs e) { if (!char.IsControl(e.KeyChar) && !char.IsDigit(e.KeyChar) && (e.KeyChar != '.')) { e.Handled = true; } // only allow one decimal point if ((e.KeyChar == '.') && ((sender as TextBox).Text.IndexOf('.') > -1)) { e.Handled = true; } }

Kishore Konatham · Answer

It is just concatenating. I need this to perform addition. If i enter 2 and click on add in form1, it should display 13. i.e (11+2).