c# - How to output Debug Information to a RichTextBox? -

i'm creating ftp client , wish output responses richtextbox outputting debug information.

would able on how this? thanks

public fileark() {     initializecomponent();     hostaddress.text = "host";     username.text = "foo";     password.text = "bar";     //ftptrace.addlistener(new textwritertracelistener(responsewindow.text));    // debug.writeline(responsewindow.text); }  private void connect_click(object sender, eventargs e) {     conn = new ftpclient();     conn.host = hostaddress.text;     conn.credentials = new networkcredential(username.text, password.text);     conn.connect();   }  private void disconnect_click(object sender, eventargs e) {     conn.disconnect(); }  private void responsewindow_textchanged(object sender, eventargs e) {  } 

you can implement own tracelistener gets configured in app.config , dynamically tries find richtextbox matches name in config.

your class can this:

public class textboxlistener : tracelistener {     richtextbox _box;     string _data;     public textboxlistener(string initializedata)     {         _data = initializedata;     }      private bool init()     {         if (_box != null && _box.isdisposed )         {             // null if control disposed             _box = null;         }         // find logger text box         if (_box == null)         {             // open forms             foreach (form f in application.openforms)             {                 // controls on forms                 foreach (control c in f.controls)                 {                     // name match                      if (c.name == _data && c richtextbox)                     {                         // found one!                         _box = (richtextbox) c;                         break;                     }                 }             }         }         return _box != null && !_box.isdisposed;     }      public override void writeline(string message)     {         if (init())         {             _box.text = _box.text + message + "\r\n";         }     }      public override void write(string message)     {         if (init())         {             _box.text = _box.text + message;         }     } } 

most important part of class init method iterates on openforms , controls find richtextbox control matches name configured in app.config.

to make use of class configure tracing in app.config , add listener

<system.diagnostics>     <trace>       <listeners>         <add name="box"               type="windowsformsapplication1.textboxlistener, windowsformsapplication1"               initializedata="loggerrtb" />       </listeners>     </trace>   </system.diagnostics> 

the type qualified typename of class (namespace.classname, assemblyname) , in initializedata you'll add name of richtextbox control on form. in example app loggerrtb.

in app can use standard trace class now:

trace.writeline("hello world"); 

notice textboxlistener instantiated on first call trace.writeline.

one of benefits of approach possibility add multiple listeners write different richtextbox controls, on separate forms (assuming forms open).