How do I pass a value from a child back to the parent form

Question

How do I pass a value from a child back to the parent form  I have a string that I would like to pass back to the parent   I launched the child using   FormOptions formOptions   new FormOptions    formOptions ShowDialog

User · Answer

If you are displaying child form as a modal dialog box, you can set DialogResult property of child form with a value from the DialogResult enumeration which in turn hides the modal dialog box, and returns control to the calling form. At this time parent can access child form's data to get the info that it need.

For more info check this link: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.dialogresult(v=vs.110).aspx

User · Answer

You can also create a public property      Using and namespace     public partial class FormOptions   Form       private string  MyString         Use this     public string MyString           in        get   return  MyString          NET                                      2 0      public string MyString   get       In  NET 3 0 or newer         The rest of the form code     Then you can get it with   FormOptions formOptions   new FormOptions    formOptions ShowDialog     string myString   formOptions MyString

User · Answer

You can also create an overload of ShowDialog in your child class that gets an out parameter that returns you the result   public partial class FormOptions   Form     public DialogResult ShowDialog out string result          DialogResult dialogResult   base ShowDialog         result   m Result      return dialogResult

User · Answer

You can also create an overload of ShowDialog in your child class that gets an out parameter that returns you the result   public partial class FormOptions   Form     public DialogResult ShowDialog out string result          DialogResult dialogResult   base ShowDialog         result   m Result      return dialogResult

User · Answer

The fastest and more flexible way to do that is passing the parent to the children from the constructor as below   Declare a property in the parent form  public string MyProperty  get  set    Declare a property from the parent in child form  private ParentForm ParentProperty  get  set    Write the child s constructor like this    public ChildForm ParentForm parent         ParentProperty  parent        Change the value of the parent property everywhere in the child form  ParentProperty MyProperty    quot New value quot     It s done  the property MyProperty in the parent form is changed  With this solution  you can change multiple properties from the child form  So delicious  no

User · Answer

The fastest and more flexible way to do that is passing the parent to the children from the constructor as below   Declare a property in the parent form  public string MyProperty  get  set    Declare a property from the parent in child form  private ParentForm ParentProperty  get  set    Write the child s constructor like this    public ChildForm ParentForm parent         ParentProperty  parent        Change the value of the parent property everywhere in the child form  ParentProperty MyProperty    quot New value quot     It s done  the property MyProperty in the parent form is changed  With this solution  you can change multiple properties from the child form  So delicious  no

User · Answer

Create a property  or method  on FormOptions  say GetMyResult   using  FormOptions formOptions   new FormOptions          formOptions ShowDialog         string result   formOptions GetMyResult          do what ever with result

User · Answer

Well I have just come across the same problem here - maybe a bit different  However  I think this is how I solved it    in my parent form I declared the child form without instance e g  RefDateSelect myDateFrm  So this is available to my other methods within this class  form next  a method displays the child by new instance   myDateFrm   new RefDateSelect    myDateFrm MdiParent   this  myDateFrm Show    myDateFrm Focus     my third method  which wants the results from child  can come at any time  amp  simply get results    PDateEnd   myDateFrm JustGetDateEnd    pDateStart   myDateFrm JustGetDateStart       Note  the child methods JustGetDateStart   are public within CHILD as   public DateTime JustGetDateStart         return DateTime Parse this dtpStart EditValue ToString          I hope this helps

User · Answer

For Picrofo EDY  It depends  if you use the ShowDialog   as a way of showing your form and to close it you use the close button instead of this Close    The form will not be disposed or destroyed  it will only be hidden and changes can be made after is gone  In order to properly close it you will need the Dispose   or Close   method  In the other hand  if you use the Show   method and you close it  the form will be disposed and can not be modified after

User · Answer

i had same problem i solved it like that   here are newbies step by step  instruction   first create object of child form it top of your form class   then use that object for every operation of child form like showing child form and reading value from it   example  namespace ParentChild         Parent Form Class     public partial class ParentForm   Form                  Forms Objects         ChildForm child obj   new ChildForm                 Show Child Forrm         private void ShowChildForm Click object sender  EventArgs e                        child obj ShowDialog                         Read Data from Child Form          private void ReadChildFormData Click object sender  EventArgs e                        int ChildData   child obj child value      it will have 12345                     parent form class end point         Child Form Class     public partial class ChildForm   Form                public int child value   0        variable where we will store value to be read by parent form               save something into child value  variable and close child form          private void SaveData Click object sender  EventArgs e                        child value   12345       save 12345 value to variable             this Close        close child form                     child form class end point         name space end point

User · Answer

Use public property of child form  frmOptions        public string Result     frmMain        frmOptions ShowDialog    string r   frmOptions Result      Use events  frmMain        frmOptions OnResult    new ResultEventHandler frmMain frmOptions Resukt        frmOptions ShowDialog        Use public property of main form  frmOptions        public frmMain MainForm  MainForm Result    result      frmMain        public string Result       frmOptions MainForm   this       frmOptions ShowDialog         string r   this Result      Use object Control Tag  This is common for all controls public property which can contains a System Object  You can hold there string or MyClass or MainForm - anything   frmOptions        this Tag    result     frmMain        frmOptions ShowDialog         string r   frmOptions Tag as string

User · Answer

When you use the ShowDialog   or Show   method  and then close the form  the form object does not get completely destroyed  closing    destruction   It will remain alive  only it s in a  closed  state  and you can still do things to it

User · Answer

Use public property of child form  frmOptions        public string Result     frmMain        frmOptions ShowDialog    string r   frmOptions Result      Use events  frmMain        frmOptions OnResult    new ResultEventHandler frmMain frmOptions Resukt        frmOptions ShowDialog        Use public property of main form  frmOptions        public frmMain MainForm  MainForm Result    result      frmMain        public string Result       frmOptions MainForm   this       frmOptions ShowDialog         string r   this Result      Use object Control Tag  This is common for all controls public property which can contains a System Object  You can hold there string or MyClass or MainForm - anything   frmOptions        this Tag    result     frmMain        frmOptions ShowDialog         string r   frmOptions Tag as string

User · Answer

You can also create a public property      Using and namespace     public partial class FormOptions   Form       private string  MyString         Use this     public string MyString           in        get   return  MyString          NET                                      2 0      public string MyString   get       In  NET 3 0 or newer         The rest of the form code     Then you can get it with   FormOptions formOptions   new FormOptions    formOptions ShowDialog     string myString   formOptions MyString

User · Answer

I think the easiest way is to use the Tag property in your FormOptions class set the Tag   value you need to pass and after the ShowDialog method read it as   myvalue x  myvalue formoptions Tag

User · Answer

Use public property of child form  frmOptions        public string Result     frmMain        frmOptions ShowDialog    string r   frmOptions Result      Use events  frmMain        frmOptions OnResult    new ResultEventHandler frmMain frmOptions Resukt        frmOptions ShowDialog        Use public property of main form  frmOptions        public frmMain MainForm  MainForm Result    result      frmMain        public string Result       frmOptions MainForm   this       frmOptions ShowDialog         string r   this Result      Use object Control Tag  This is common for all controls public property which can contains a System Object  You can hold there string or MyClass or MainForm - anything   frmOptions        this Tag    result     frmMain        frmOptions ShowDialog         string r   frmOptions Tag as string

User · Answer

If you re just using formOptions to pick a single value and then close  Mitch s suggestion is a good way to go   My example here would be used if you needed the child to communicate back to the parent while remaining open   In your parent form  add a public method that the child form will call  such as  public void NotifyMe string s           Do whatever you need to do with the string     Next  when you need to launch the child window from the parent  use this code   using  FormOptions formOptions   new FormOptions             passing this in ShowDialog will set the  Owner         property of the child form     formOptions ShowDialog this       In the child form  use this code to pass a value back to the parent   ParentForm parent    ParentForm this Owner  parent NotifyMe  whatever      The code in this example would be better used for something like a toolbox window which is intended to float above the main form   In this case  you would open the child form  with  TopMost   true  using  Show   instead of  ShowDialog     A design like this means that the child form is tightly coupled to the parent form  since the child has to cast its owner as a ParentForm in order to call its NotifyMe method    However  this is not automatically a bad thing

User · Answer

Create a property  or method  on FormOptions  say GetMyResult   using  FormOptions formOptions   new FormOptions          formOptions ShowDialog         string result   formOptions GetMyResult          do what ever with result

User · Answer

You can also create a public property      Using and namespace     public partial class FormOptions   Form       private string  MyString         Use this     public string MyString           in        get   return  MyString          NET                                      2 0      public string MyString   get       In  NET 3 0 or newer         The rest of the form code     Then you can get it with   FormOptions formOptions   new FormOptions    formOptions ShowDialog     string myString   formOptions MyString

User · Answer

I think the easiest way is to use the Tag property in your FormOptions class set the Tag   value you need to pass and after the ShowDialog method read it as   myvalue x  myvalue formoptions Tag

User · Answer

Well I have just come across the same problem here - maybe a bit different  However  I think this is how I solved it    in my parent form I declared the child form without instance e g  RefDateSelect myDateFrm  So this is available to my other methods within this class  form next  a method displays the child by new instance   myDateFrm   new RefDateSelect    myDateFrm MdiParent   this  myDateFrm Show    myDateFrm Focus     my third method  which wants the results from child  can come at any time  amp  simply get results    PDateEnd   myDateFrm JustGetDateEnd    pDateStart   myDateFrm JustGetDateStart       Note  the child methods JustGetDateStart   are public within CHILD as   public DateTime JustGetDateStart         return DateTime Parse this dtpStart EditValue ToString          I hope this helps

User · Answer

You can also create a public property      Using and namespace     public partial class FormOptions   Form       private string  MyString         Use this     public string MyString           in        get   return  MyString          NET                                      2 0      public string MyString   get       In  NET 3 0 or newer         The rest of the form code     Then you can get it with   FormOptions formOptions   new FormOptions    formOptions ShowDialog     string myString   formOptions MyString

User · Answer

If you re just using formOptions to pick a single value and then close  Mitch s suggestion is a good way to go   My example here would be used if you needed the child to communicate back to the parent while remaining open   In your parent form  add a public method that the child form will call  such as  public void NotifyMe string s           Do whatever you need to do with the string     Next  when you need to launch the child window from the parent  use this code   using  FormOptions formOptions   new FormOptions             passing this in ShowDialog will set the  Owner         property of the child form     formOptions ShowDialog this       In the child form  use this code to pass a value back to the parent   ParentForm parent    ParentForm this Owner  parent NotifyMe  whatever      The code in this example would be better used for something like a toolbox window which is intended to float above the main form   In this case  you would open the child form  with  TopMost   true  using  Show   instead of  ShowDialog     A design like this means that the child form is tightly coupled to the parent form  since the child has to cast its owner as a ParentForm in order to call its NotifyMe method    However  this is not automatically a bad thing

User · Answer

Create a property  or method  on FormOptions  say GetMyResult   using  FormOptions formOptions   new FormOptions          formOptions ShowDialog         string result   formOptions GetMyResult          do what ever with result

User · Answer

If you re just using formOptions to pick a single value and then close  Mitch s suggestion is a good way to go   My example here would be used if you needed the child to communicate back to the parent while remaining open   In your parent form  add a public method that the child form will call  such as  public void NotifyMe string s           Do whatever you need to do with the string     Next  when you need to launch the child window from the parent  use this code   using  FormOptions formOptions   new FormOptions             passing this in ShowDialog will set the  Owner         property of the child form     formOptions ShowDialog this       In the child form  use this code to pass a value back to the parent   ParentForm parent    ParentForm this Owner  parent NotifyMe  whatever      The code in this example would be better used for something like a toolbox window which is intended to float above the main form   In this case  you would open the child form  with  TopMost   true  using  Show   instead of  ShowDialog     A design like this means that the child form is tightly coupled to the parent form  since the child has to cast its owner as a ParentForm in order to call its NotifyMe method    However  this is not automatically a bad thing

User · Answer

When you use the ShowDialog   or Show   method  and then close the form  the form object does not get completely destroyed  closing    destruction   It will remain alive  only it s in a  closed  state  and you can still do things to it

User · Answer

Many ways to skin the cat here and  Mitch s suggestion is a good way  If you want the client form to have more  control   you may want to pass the instance of the parent to the child when created and then you can call any public parent method on the child

User · Answer

If you re just using formOptions to pick a single value and then close  Mitch s suggestion is a good way to go   My example here would be used if you needed the child to communicate back to the parent while remaining open   In your parent form  add a public method that the child form will call  such as  public void NotifyMe string s           Do whatever you need to do with the string     Next  when you need to launch the child window from the parent  use this code   using  FormOptions formOptions   new FormOptions             passing this in ShowDialog will set the  Owner         property of the child form     formOptions ShowDialog this       In the child form  use this code to pass a value back to the parent   ParentForm parent    ParentForm this Owner  parent NotifyMe  whatever      The code in this example would be better used for something like a toolbox window which is intended to float above the main form   In this case  you would open the child form  with  TopMost   true  using  Show   instead of  ShowDialog     A design like this means that the child form is tightly coupled to the parent form  since the child has to cast its owner as a ParentForm in order to call its NotifyMe method    However  this is not automatically a bad thing

User · Answer

For Picrofo EDY  It depends  if you use the ShowDialog   as a way of showing your form and to close it you use the close button instead of this Close    The form will not be disposed or destroyed  it will only be hidden and changes can be made after is gone  In order to properly close it you will need the Dispose   or Close   method  In the other hand  if you use the Show   method and you close it  the form will be disposed and can not be modified after

User · Answer

I think the easiest way is to use the Tag property in your FormOptions class set the Tag   value you need to pass and after the ShowDialog method read it as   myvalue x  myvalue formoptions Tag

User · Answer

I think the easiest way is to use the Tag property in your FormOptions class set the Tag   value you need to pass and after the ShowDialog method read it as   myvalue x  myvalue formoptions Tag

User · Answer

Use public property of child form  frmOptions        public string Result     frmMain        frmOptions ShowDialog    string r   frmOptions Result      Use events  frmMain        frmOptions OnResult    new ResultEventHandler frmMain frmOptions Resukt        frmOptions ShowDialog        Use public property of main form  frmOptions        public frmMain MainForm  MainForm Result    result      frmMain        public string Result       frmOptions MainForm   this       frmOptions ShowDialog         string r   this Result      Use object Control Tag  This is common for all controls public property which can contains a System Object  You can hold there string or MyClass or MainForm - anything   frmOptions        this Tag    result     frmMain        frmOptions ShowDialog         string r   frmOptions Tag as string

User · Answer

You can also create an overload of ShowDialog in your child class that gets an out parameter that returns you the result   public partial class FormOptions   Form     public DialogResult ShowDialog out string result          DialogResult dialogResult   base ShowDialog         result   m Result      return dialogResult

User · Answer

i had same problem i solved it like that   here are newbies step by step  instruction   first create object of child form it top of your form class   then use that object for every operation of child form like showing child form and reading value from it   example  namespace ParentChild         Parent Form Class     public partial class ParentForm   Form                  Forms Objects         ChildForm child obj   new ChildForm                 Show Child Forrm         private void ShowChildForm Click object sender  EventArgs e                        child obj ShowDialog                         Read Data from Child Form          private void ReadChildFormData Click object sender  EventArgs e                        int ChildData   child obj child value      it will have 12345                     parent form class end point         Child Form Class     public partial class ChildForm   Form                public int child value   0        variable where we will store value to be read by parent form               save something into child value  variable and close child form          private void SaveData Click object sender  EventArgs e                        child value   12345       save 12345 value to variable             this Close        close child form                     child form class end point         name space end point

User · Answer

You can also create an overload of ShowDialog in your child class that gets an out parameter that returns you the result   public partial class FormOptions   Form     public DialogResult ShowDialog out string result          DialogResult dialogResult   base ShowDialog         result   m Result      return dialogResult

User · Answer

Create a property  or method  on FormOptions  say GetMyResult   using  FormOptions formOptions   new FormOptions          formOptions ShowDialog         string result   formOptions GetMyResult          do what ever with result

User · Answer

Many ways to skin the cat here and  Mitch s suggestion is a good way  If you want the client form to have more  control   you may want to pass the instance of the parent to the child when created and then you can call any public parent method on the child

User · Answer

If you are displaying child form as a modal dialog box, you can set DialogResult property of child form with a value from the DialogResult enumeration which in turn hides the modal dialog box, and returns control to the calling form. At this time parent can access child form's data to get the info that it need.

For more info check this link: http://msdn.microsoft.com/en-us/library/system.windows.forms.form.dialogresult(v=vs.110).aspx

User · Answer

Many ways to skin the cat here and  Mitch s suggestion is a good way  If you want the client form to have more  control   you may want to pass the instance of the parent to the child when created and then you can call any public parent method on the child

User · Answer

Many ways to skin the cat here and  Mitch s suggestion is a good way  If you want the client form to have more  control   you may want to pass the instance of the parent to the child when created and then you can call any public parent method on the child

[c#] How do I pass a value from a child back to the parent form?

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