Control timer in form 1 from form 2, C#

问题:

A label in form is displaying the count of timer. Now i want to stop,start and reset it using form 2. How can i do this.plz help

回答1:

Forms are just classes, and the timer on Form 2 is an object inside that class.

You can change the Modifiers property of your timer to public, and then instantiate Form 2 inside Form 1, call the Show() method of Form 2, and then access your timer object which is now public.

So you have a project with 2 forms like so:

Create a button in Form 1 like so:

Place a timer object on Form 2 and change the access modifier like so:

Then put the following code under your button in form one:

private void button1_Click(object sender, EventArgs e)
{
    Form2 f2 = new Form2();
    f2.Show();
    f2.timer1.Enabled = true;
}

Now you can launch form 2 and access all of the properties on the timer on form 2 from form 1.

Does this help?

回答2:

If the timer object resides in Form1, then create a public property for it:

public Timer Form1Timer { get { return timer1; } }

Then you can access this timer by having a reference to Form 1 in Form 2. You can do this by passing it in to the constructor, or having a set property on Form2. Once you have a reference to Form1, you can simply call methods on the timer:

Form1.Form1Timer.Start();

You can always create a singleton out of Form1 if you cannot pass a reference of it to Form2.

Declare your singleton:

private static Form1 _singleton

Initialize your singleton if it isnt already, and return it:

 public static Form1 Singleton
 { 
    get { _singleton ?? (_singleton = new Form1()); } 
 }

For best practices, make your Form1 constructor private. This of course will not work if Form1 does not have a default constructor (parameterless).

Then in Form2:

Form1.Singleton.Form1Timer.Start();

回答3:

Do this

static Form1 _frmObj;
public static Form1 frmObj
{
     get { return _frmObj; }
     set { _frmObj = value; }
}

On Form load

private void Form1_Load(object sender, EventArgs e)
{
      frmObj= this;
}

Access form and it's controls from another form

Form1.frmObj.timer1.Stop();