How to check in form2 if a button on form1 has been clicked

[Lucy]

I have two forms. Form1 has a textbox and a button. Form2 has a label. When the button on form1 is clicked, form2 is opened and the text in the textbox in form1 is shown in the label of form2. To get the text in the textbox to appear in the label, the code I have for this is in the Form load event. In this event I want to check if the button on form 1 has been clicked. How do I do this? I can access the button (located on form1) from form 2 by firstly making this public and then using this code: ((Form1)frm1).button1. I do not know how to finish this line of code while it is in an IF statement. Lucy

[blackjack2150]

You can create a bool variable in Form1 and set it to true in the click event handler of your button. Then check it's value from your method in Form2.

[Lucy]

Sorry I'm not sure how to do that. Can you explain your answer please? Lucy

[Malcolm Smart]

Events and delegates. Either get Form2 to subscribe to Form1.Button's onclick event or capture the onclick event on form1 and tell Form2 it has been clicked using a delegate :- //in form1 public Event Eventhandler OnButton1Click; void form1_buttonClicked( objects sender , EventArgs args) { //handler tied to the actual button click on form 1 //do other stuff //tell any subscribers we've been clicked if (OnButton1Click != null) OnButton1Click( sender , args ); } ///form2 public void MyHandler( object sender , EventArgs args) { ///button on form1 has been clicked } //in ctor or some initialiser of Form2 form1.OnButton1Click += MyHandler;

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[Xmen Real]

set modifiers of your form2`s label to "public" in properties then in button`s click event ,writes these codes

form2 frm = new form2();
frm.label2.Text = textbox1.Text;
frm.Show();
//or ShowDialog

hope it will help...

Becoming Programmer...

[Lucy]

I have tried that but it comes up with this error when you click the button: Additional information: Object reference not set to an instance of an object. I do not understand the other comments people have made as I am still very new to c#. Lucy

[Xmen Real]

i think you are clicking button when your textbox value is null

Becoming Programmer...

[Lucy]

No the error still occurs when the textbox has text in it.

[Xmen Real]

you are doing some mistakes

Becoming Programmer...

[Pete OHanlon]

Yup - one of the first mistakes is making a control public. You really shouldn't make controls public because you have opened up the whole scope of what the control can do to another unrelated instance.

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[Anthony Mushrow]

Another way is like this: Add another Label to your class variables: private System.Windows.Forms.Label Form2Label; Create a method in form one like this: public void getLabel(Label label) { Form2Label = label; } Then, when you click the button in Form1 just add a bit of extra code. Form2Label.Text = this.TextBox.Text; Now when you start Form2, run the method, and pass it the label. Form1.getLabel(this.label); That should work. You'd have to try it out.

[Paras Kaneriya]

Try using this way declare a bool variable in form2 with public accessiblity like public bool clicked; and in the form load event you can check like if (clicked) { //do whatever you want to do when button1 on form1 is clicked } in form1's button1's click event write private void button1_Click(object sender, EventArgs e) { Form2 frm = new Form2(); frm.clicked = true; frm.Show(); }

Paras Kaneriya
The difference between genius and stupidity is that genius has its limits.