c# - Keeping the image in form -

i made 2 forms. form2 has button set background image. got :

this.backgroundimage = new bitmap(properties.resources._1334821694552, new size(800, 500)); //_1334821694552 name of image 

how change background in forms button click stay way until picture chosen?

if understand correctly, have form form2 contains buttons change background image on form form1.

i wonder why use this.backgroundimage in form2 change background image? change background image on form2, not on form1.

you should passing reference form1 form2 , use form1.backgroundimage = ....

this bit vague - suggest edit question add information on how relation between form1 , form2 is.

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first of all, need pass instance of form1 form2. done in constructor, example, assuming form2 opened in form1. example this:

code in form2

// in form2, there's member variable holds form1 reference private form1 m_form1instance;  // constructor of form2 public form2(form1 form1instance) {     ...      // remember form1-instance     m_form1instance = form1instance; }  // when button clicked in form2, background image in form1 changed private void button1_click(object sender, eventargs e) {     m_form1instance.backgroundimage = ...; } 

code in form1

// when form2 opened, pass "this" constructor. following // sample opens form2 modal dialog using (form2 f2 = new form2(this)) {     f2.showdialog(this); } 

that should change background image on form1, , not on form2.

if want save, background image displayed across sessions (i.e. want same background image appear, when program restarted), use wink's answer. saves background image used settings.

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ok, seems want globally change background image on forms in application. have take way 1 described above.

what i'd create singleton class describes current background image , has events notify subscribers when image has been changed. this, example:

public class backgroundimageholder {     private static backgroundimageholder m_instance;     private bitmap m_backgroundimage;      public event eventhandler backgroundimagechanged;      private backgroundimageholder() { }      public static backgroundimageholder instance     {                 {             if (m_instance == null) m_instance = new backgroundimageholder();             return m_instance;         }     }      public bitmap backgroundimage     {         { return m_backgroundimage; }         set {            m_backgroundimage = value;            onbackgroundimagechanged();         }     }      protected void onbackgroundimagechanged()     {         if (backgroundimagechanged != null)             backgroundimagechanged(this, eventargs.empty);     } } 

whenever open form (i.e. in constructor) query backgroundimageholder current image , set form:

this.backgroundimage = backgroundimageholder.instance.backgroundimage; 

then subscribe notification, form can change background image whenever necessary:

backgroundimageholder.instance.backgroundimagechanged += backgroundimageholder_changed; 

you need implement event handler:

private void backgroundimageholder_changed(object sender, eventargs e) {     this.backgroundimage = backgroundimageholder.instance.backgroundimage; } 

then, globally change image, it's necessary tell backgroundimageholder new image:

backgroundimageholder.instance.backgroundimage = ...; 

done.