compare string to button text

Collapse
This topic is closed.
X
X
Collapse
 
  • Page of 1
  • Time
  • Show
Clear All
new posts
Previous template Next
  • Demosthenes
    #1

    compare string to button text

    I am using visual c++ 2003 i believe.

    I created a new win32 application, and put 1 button on the form and
    changed it's text to "Start".


    and this code does not work:


    private: System::Void button1_Click(S ystem::Object * sender,
    System::EventAr gs * e)
    {
    if (button1->Text == "Start")
    {
    button1->Text = "Stop";
    }
    else
    {
    button1->Text == "Start";
    }
    }


    the project compiles ok, but when the code executes, the if statement
    always goes to the else clause. The text on the button is "Start"
    though. I think I am not understanding some fundamental concepts
    with
    pointers/objects....


    Tags: None
    • Cholo Lennon
      #2
      Re: compare string to button text

      Demosthenes wrote:
      I am using visual c++ 2003 i believe.
      >
      I created a new win32 application, and put 1 button on the form and
      changed it's text to "Start".
      >
      >
      and this code does not work:
      >
      >
      private: System::Void button1_Click(S ystem::Object * sender,
      System::EventAr gs * e)
      {
      if (button1->Text == "Start")
      {
      button1->Text = "Stop";
      }
      else
      {
      button1->Text == "Start";
      }
      }
      >
      >
      the project compiles ok, but when the code executes, the if statement
      always goes to the else clause. The text on the button is "Start"
      though. I think I am not understanding some fundamental concepts
      with
      pointers/objects....
      When comparing add S prefix to your literals:

      if (button1->Text == S"Start")
      ...
      else
      ...

      Take a look to:

      Code Project
      http://www.codeproject.com/KB/mcpp/managed_types.aspx
      Code Project - For Those Who Code

      Managed C++ String Equality (Reference Objects Equality)
      http://punkouter.wordpress.com/2007/03/22/managed-c-string-equality-reference-ob
      Here’s a bug that recently crept into my project. A teammate made a simple comparison between strings like this: String* a = “abc”; String* b = “abc”; if ( a == b ) { …

      jects-equality/


      Regards


      --
      Cholo Lennon
      Bs.As.
      ARG



        Comment

        • Ben Voigt [C++ MVP]
          #3
          Re: compare string to button text

          Cholo Lennon wrote:
          Demosthenes wrote:
          >I am using visual c++ 2003 i believe.
          >>
          >I created a new win32 application, and put 1 button on the form and
          >changed it's text to "Start".
          >>
          >>
          >and this code does not work:
          >>
          >>
          >private: System::Void button1_Click(S ystem::Object * sender,
          >System::EventA rgs * e)
          > {
          > if (button1->Text == "Start")
          > {
          > button1->Text = "Stop";
          > }
          > else
          > {
          > button1->Text == "Start";
          > }
          > }
          >>
          >>
          >the project compiles ok, but when the code executes, the if statement
          >always goes to the else clause. The text on the button is "Start"
          >though. I think I am not understanding some fundamental concepts
          >with
          >pointers/objects....
          >
          When comparing add S prefix to your literals:
          >
          if (button1->Text == S"Start")
          or even better,

          if (button1->Text->Equals(S"Start "))

          This makes it clear it is not pointer comparison.
          ...
          else
          ...
          >
          Take a look to:
          >
          Code Project
          http://www.codeproject.com/KB/mcpp/managed_types.aspx
          Code Project - For Those Who Code

          Managed C++ String Equality (Reference Objects Equality)
          http://punkouter.wordpress.com/2007/03/22/managed-c-string-equality-reference-ob
          Here’s a bug that recently crept into my project. A teammate made a simple comparison between strings like this: String* a = “abc”; String* b = “abc”; if ( a == b ) { …

          jects-equality/
          >
          >
          Regards

            Comment

            • Demosthenes
              #4
              Re: compare string to button text

              On Mar 27, 5:14 pm, "Ben Voigt [C++ MVP]" <r...@nospam.no spamwrote:
              Cholo Lennon wrote:
              Demostheneswrot e:
              I am using visual c++ 2003 i believe.
              >
              I created a new win32 application, and put 1 button on the form and
              changed it's text to "Start".
              >
              and this code does not work:
              >
              private: System::Void button1_Click(S ystem::Object *  sender,
              System::EventAr gs *  e)
                  {
                         if (button1->Text == "Start")
                      {
                        button1->Text = "Stop";
                          }
                    else
                      {
                        button1->Text == "Start";
                       }
                  }
              >
              the project compiles ok, but when the code executes, the if statement
              always goes to the else clause.  The text on the button is "Start"
              though.  I think I am not understanding some fundamental concepts
              with
              pointers/objects....
              >
              When comparing add S prefix to your literals:
              >
              if (button1->Text == S"Start")
              >
              or even better,
              >
              if (button1->Text->Equals(S"Start "))
              >
              This makes it clear it is not pointer comparison.
              >
              >
              >
                     ...
              else
                     ...
              >
              Take a look to:
              >
              Code Project
              http://www.codeproject.com/KB/mcpp/managed_types.aspx
              Code Project - For Those Who Code

              http://punkouter.wordpress.com/2007/...ing-equality-r...
              jects-equality/
              >
              Regards- Hide quoted text -
              >
              - Show quoted text -- Hide quoted text -
              >
              - Show quoted text -
              thanks guys, now i run into a strange thing here, the first time i
              press the button, the buttons text = start, and gets set to stop.
              Then from stop to start, then it never works again. here is my code

              if (button1->Text == S"Start")
              {
              button1->Text = "Stop";
              }
              else
              {
              button1->Text = "Start";
              }



                Comment

                • Demosthenes
                  #5
                  Re: compare string to button text

                  On Mar 28, 9:37 am, Demosthenes <sadbastur...@y ahoo.comwrote:
                  On Mar 27, 5:14 pm, "Ben Voigt [C++ MVP]" <r...@nospam.no spamwrote:
                  >
                  >
                  >
                  >
                  >
                  Cholo Lennon wrote:
                  >Demostheneswro te:
                  >I am using visual c++ 2003 i believe.
                  >
                  >I created a new win32 application, and put 1 button on the form and
                  >changed it's text to "Start".
                  >
                  >and this code does not work:
                  >
                  >private: System::Void button1_Click(S ystem::Object *  sender,
                  >System::EventA rgs *  e)
                  >    {
                  >           if (button1->Text == "Start")
                  >        {
                  >          button1->Text = "Stop";
                  >            }
                  >      else
                  >        {
                  >          button1->Text == "Start";
                  >         }
                  >    }
                  >
                  >the project compiles ok, but when the code executes, the if statement
                  >always goes to the else clause.  The text on the button is "Start"
                  >though.  I think I am not understanding some fundamental concepts
                  >with
                  >pointers/objects....
                  >
                  When comparing add S prefix to your literals:
                  >
                  if (button1->Text == S"Start")
                  >
                  or even better,
                  >
                  if (button1->Text->Equals(S"Start "))
                  >
                  This makes it clear it is not pointer comparison.
                  >
                         ...
                  else
                         ...
                  >
                  Take a look to:
                  >
                  >http://www.codeproject.com/KB/mcpp/managed_types.aspx
                  >http://punkouter.wordpress.com/2007/...ing-equality-r....
                  jects-equality/
                  >
                  Regards- Hide quoted text -
                  >
                  - Show quoted text -- Hide quoted text -
                  >
                  - Show quoted text -
                  >
                  thanks guys, now i run into a strange thing here, the first time i
                  press the button, the buttons text = start, and gets set to stop.
                  Then from stop to start, then it never works again.  here is my code
                  >
                       if (button1->Text == S"Start")
                          {
                            button1->Text = "Stop";
                          }
                        else
                          {
                            button1->Text = "Start";
                          }- Hide quoted text -
                  >
                  - Show quoted text -
                  but this seems to work fine:

                  if (button1->Text->Equals(S"Start "))
                  {
                  button1->Text = "Stop";
                  timer1->Enabled = true;
                  timer1->Start;
                  }
                  else
                  {
                  button1->Text = "Start";
                  timer1->Stop;
                  timer1->Enabled = false;
                  }

                    Comment

                    Previous template Next
                    Working...