Not able to Save the new Value replacing the old value with the respective key in the text file on clicking a button in C#

Question

I am not able to save the new value to the old value with the same key ie........... new value given to the same key is not getting saved in the text file from the below source code in the button click event even after the key remains the same.

Please find me a solution for this problem in C#

Attachment: filereadformsauto.rar

Vulpes · Answer

Try making the changes I've highlighted: private void comboBox2_SelectedIndexChanged(object sender EventArgs e) { string key = string.Empty; / need to reset key to empty each time try { if (tab == null) //If Hashtable not yet loaded { tab = new Hashtable();//now refers to Field. lines = File.ReadAllLines(path); //The above Statement refers to Fields. foreach (string line in lines) { // This statement refers to field so use if block to search for containing any equality = sign. if (line.Contains(=)) { string[] items = line.Split('='); tab.Add(items[0] int.Parse(items[1])); } } } if (tab.ContainsKey(comboBox2.SelectedItem.ToString())) { key = comboBox2.SelectedItem.ToString(); textBox1.Text = tab[key].ToString(); } else { MessageBox.Show(Invalid Key or Command Selected....
Please Select A Valid Device & Operation); } } catch (Exception Ex) { MessageBox.Show(Ex.Message); } } private void button1_Click(object sender EventArgs e) { if(string.IsNullOrEmpty(key)||lines==null) return; int code; if(!int.TryParse(textBox1.Textout code)) { MessageBox.Show(You Entered InValid Code.....
Please Enter A Valid Code Correctly.); textBox1.Focus(); } string search=key+=; int index = -1; // this should be -1 for (int i = 0; i { if (lines[i].StartsWith(search)) { index=i; break; } } if(index > -1 && Convert.ToInt32(tab[key])!=code) // this should be index > -1 { lines[index]=search+code.ToString(); File.WriteAllLines(path lines);// you should be writing the file not reading it tab[key]=code; MessageBox.Show(The Revised Code has been Changed Successfully); } }