Pass values between windows form forms and reference master notes

Summary of passing values between windows Forms
After passing values between windows Forms, I have summarized four methods: global variables, attributes, form constructors, and delegate.

The first global variable:

This is the simplest, as long as the variable is described as static, and the form1 variable is directly referenced in form2. The Code is as follows:

Define a static variable public static int I = 9 in form1;

The buttons in Form2 are as follows:

Private void button#click (object sender, System. EventArgs e)

{

TextBox1.Text = Form1. I. ToString ();

}

 

The second method is to use attributes. For details, see my blog:

Http://blog.csdn.net/tjvictor/archive/2006/06/04/772711.aspx

 

The third method is to use constructor:

The button of Form1 is written as follows:

Private void button#click (object sender, System. EventArgs e)

{

Form2 temp = new Form2 (9 );

Temp. Show ();

}

 

The Form2 constructor is written as follows:

Public form2 (int I)

{

Initializecomponent ();

Textbox1.text = I. tostring ();

}

 

The fourth method is to use delegate. The Code is as follows:

Form2 first defines a delegate

Public Delegate void returnvalue (int I );

Public returnvalue;

The code for the button in form2 is as follows:

Private void button#click (Object sender, system. eventargs E)

{

If (returnvalue! = NULL)

Returnvalue (8 );

}

 

The buttons in form1 are as follows:

Private void button#click (Object sender, system. eventargs E)

{

Form2 temp = new form2 ();

Temp. ReturnValue = new temp. Form2.returnvalue (showvalue );

Temp. Show ();

}

 

Private void showvalue (int I)

{

TextBox1.Text = I. ToString ();

}

 

Click the button of form2 to change the value in the textbox of form1.

 

In the four methods,

The first one is two-way data transfer. That is to say, if form1 and form2 change the I value, the other party will also be affected.

The second method can be unidirectional or bidirectional value transfer.

The third method is form1-> form2 unidirectional value transfer.

The fourth method is form2-> form1 one-way pass value.

 

I will add a new method in the future. Another method is to use event, which is similar to delegate. I will not talk about it here.

 

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