Form between traditional values, pass parent form subform

The first method: the entire form as the value passed Form1 Form2

                            

form1 button1 pop from2,

from2 numericUpDown1 value changes, so that the value of change form1 textBox1.

Form1 Code:

        // The first method: pass the entire form as the value of Form2 
        Private  void the button1_Click ( Object SENDER, EventArgs E)
        {
            Form frm2 = new Form2(this);
            frm2.ShowDialog();
        }
        
       // change value textBox1 
        public  void ChangeText ( String S)
        {
            this.textBox1.Text = s;
        }

Form2 Code:

       // will pass over all Form1 assigned to f1, so that you can call in here Form1 
        Private Form1 f1;
         public Form2 (Form1 frm1)
        {
            InitializeComponent();
            f1 = frm1;
        }

        private void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
            // call Form1 in changetext event 
            f1.ChangeText (numericUpDown1.Value.ToString ());
        }

 

The second method: delegate to the event

         

 

form1 button1 pop from2,

from2 numericUpDown1 value changes, so that the value of change form1 textBox1,

from2 numericUpDown1 empty value, so that the value of the empty form1 textBox1.

Form1 Code:

        // 2. Registration Event 
        Private  void button1_Click ( Object SENDER, EventArgs E)
        {
            Frm3 Form3 = new new Form3 ();
             // write the + =, pressing the Tab key twice will automatically generate frm3_changed, frm3_empty two events 
            frm3.UpdateTextValueEvent + = new new Form3.ChangeTextValueDelegate (frm3_changed); // event value change 
            frm3 + = .EmptyTextValueEvent new new Form3.ChangeTextValueDelegate (frm3_empty); // event empty value 
            frm3.ShowDialog ();
        }

        // change the value of the event 
        Private  void frm3_changed ( String S)
        {
            this.textBox1.Text = s;
        }

        // clear the value of the event 
        Private  void frm3_empty ( String S)
        {
            this.textBox1.Text = "";
        }

Form3 Code:

        // delegate 1. Define two parameters and events 
        public  the delegate  void ChangeTextValueDelegate ( String S);
         public  Event ChangeTextValueDelegate UpdateTextValueEvent;
         public  Event ChangeTextValueDelegate EmptyTextValueEvent;

        //3.传值 
        private void numericUpDown1_ValueChanged(object sender, EventArgs e)
        {
            UpdateTextValueEvent(numericUpDown1.Value.ToString());
        }
        private void button1_Click(object sender, EventArgs e)
        {
            EmptyTextValueEvent(numericUpDown1.Value.ToString());
        }