how to call user control from another user control in c#?

Question

I have one problem for calling user control from another user control my code like this :

 public UserControl1()
        {
            InitializeComponent();
}

        private void commandBarButtonInsert_Click(object sender, EventArgs e)
        {


            UserControl2 usr2 = new UserControl2();
            this.Hide();
            this.Parent.Controls.Add(usr2);
}

it is returning this error :

System.NullReferenceException: Object reference not set to an instance of an object

. How can I solve this problem ?

How is that different? You get a NullRefenreceException. Something Is Null. I'm guessing `this.Parent`. Debug, find what is null, and fix it. Simple. — Zohar Peled, Mar 08 '18 at 10:26
I cannot debug because it is dll it using from another application. — Sezer Erdogan, Mar 08 '18 at 10:28
[how to debug a dll c#](https://www.google.co.il/search?q=how+to+debug+a+dll+c%23&rlz=1C1LENP_iwIL718IL718&oq=how+to+debug+a+dll&aqs=chrome.2.69i57j0l5.9263j0j7&sourceid=chrome&ie=UTF-8) — Zohar Peled, Mar 08 '18 at 10:31
I done like this but I have error : http://www.c-sharpcorner.com/blogs/calling-another-user-control-from-one1 — Sezer Erdogan, Mar 08 '18 at 10:32

score 1 · Answer 1 · answered Mar 08 '18 at 09:59

1

The problem is that you are not trying to add a control to the parent (maybe Form1) but you are trying to add the UserControl2 as parent of UserControl1. That is not possible.

Quick and dirty would be something like this:

        UserControl2 usr2 = new UserControl2 ();
        this.Hide();
        Form1 parentForm = (this.Parent as Form1);

        parentForm.Controls.Add(new usr2());

answered Mar 08 '18 at 09:59

M Stoerzel

300
1
13

I cannot use Form.I have to use only user controls on my application. – Sezer Erdogan Mar 08 '18 at 10:28
http://www.c-sharpcorner.com/blogs/calling-another-user-control-from-one1 I done like this – Sezer Erdogan Mar 08 '18 at 10:31
@SezerErdogan what does your hierarchy look like? Which Control is the parent of which? – M Stoerzel Mar 08 '18 at 10:32
UserControl1 is my parent control – Sezer Erdogan Mar 08 '18 at 10:33
@SezerErdogan And you want to add Control2 to Control1? Then use this.Controls.Add(usr2); – M Stoerzel Mar 08 '18 at 10:40
Yes I want to call another usercontrol2 in usercontrol1 – Sezer Erdogan Mar 08 '18 at 10:44

score 0 · Answer 2 · answered Mar 08 '18 at 09:44

0

Try referencing controls with x:Name, and access them with the specified name if they are in the same XAML file.
Edit: Also, if you're getting a NullReferenceException, the problem lies within you calling a method on a NULL object.

answered Mar 08 '18 at 09:44

TheITDejan

808
9
27

score 0 · Answer 3 · answered Mar 08 '18 at 09:51

0

this.Parent is null, a basic form has no parent, but panel, for example, may have `Parent property.

Also, if you wanted to do something like this.Controls.Add(usr2); you will get System.ArgumentException because of you cant add form to another form (without any containers)

answered Mar 08 '18 at 09:51

styx

1,852
1
11
22

I done like this http://www.c-sharpcorner.com/blogs/calling-another-user-control-from-one1 – Sezer Erdogan Mar 08 '18 at 10:32
@SezerErdogan what is `windowsFormsControlLibrary` ? – styx Mar 08 '18 at 11:29

how to call user control from another user control in c#?

3 Answers3