Unable to implement textwatcher correctly in android -

hey guys looking way find out user typing in edittext , stumbled upon textwatcher. problem don't understand parameters refer in function. want keep track of text being entered user letter letter. can't figure out argument correct subscript no. have tried different variations haven't had luck those. essentially want save text entered in array until user presses ','button or exceeds limit of 24 characters. please advise.

public class main extends activity implements onclicklistener {      // inputans.setonkeylistener(this);      button go;     textview answer;     textview check;     edittext inputans, inputq;     boolean done1 = false;     char[] ans = new char[30];     string predef = "please answer question";     char[] predefc = predef.tochararray();     int len = predefc.length;     int = 0;     char[] substring = new char[30];      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);         initialisevars();         go.setenabled(false);         go.setonclicklistener(this);          inputans.addtextchangedlistener(new textwatcher() {             @override             public void ontextchanged(charsequence s, int start, int before,                     int count) {                  if ((count - before) > 0) {                     char current = s.charat(before);                                        if (current == '.' || >= 24) { // 24 check                         // ans[i]='\0';                         // inputans.settext(predef,                         // textview.buffertype.editable);                         check.settext(predef);                         go.setenabled(true);                     } else {                          ans[i] = current;                         i++; // char[] substring = char[30]; button                                 // problem,check if prev length - current length                                 // >0                          int m;                         (m = 0; m <= i; m++) {                             substring[m] = predefc[m];                         }                          check.settext(substring.tostring());                         // substring[m]='\0';                         /*                          * inputans.settext(substring.tostring(),                          * textview.buffertype.editable);                          */                      }                 }              }              @override             public void beforetextchanged(charsequence s, int start, int count,                     int after) {                  // todo auto-generated method stub             }              @override             public void aftertextchanged(editable s) {                 // todo auto-generated method stub              }         });      }      private void initialisevars() {         // todo auto-generated method stub         go = (button) findviewbyid(r.id.bgo);         answer = (textview) findviewbyid(r.id.tvans);         inputans = (edittext) findviewbyid(r.id.ettricky);         inputq = (edittext) findviewbyid(r.id.etques);         check = (textview) findviewbyid(r.id.textview1);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.main, menu);         return true;     }      @override     public void onclick(view v) {         // todo auto-generated method stub         switch (v.getid()) {         case r.id.bgo: {              answer.settext(ans.tostring());           }             break;          }     }  } 

in android documentation, can read that:

public abstract void ontextchanged (charsequence s, int start, int before, int count) added in api level 1

this method called notify that, within s, count characters beginning @ start have replaced old text had length before. error attempt make changes s callback.

it means, that:

• s modified text (you can it's length, s.length())
• count number of characters have been added
• start position in new characters have been added
• before length of text before changes

basically achieve want, i'd rather go approach instead of arrays:

@override protected void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.activity_main);     initialisevars();     go.setenabled(false);     go.setonclicklistener(this);      inputans.addtextchangedlistener(new textwatcher() {         @override         public void ontextchanged(charsequence s, int start, int before,                 int count) {              if ((s.length() - before) > 0) {  // check if text longer before changing                 char current = s.charat(before);                                    if (current == '.' || s.length() >= 24) {                     check.settext(predef);                     go.setenabled(true);                 } else {                     check.settext(s);                 }             }          }          @override         public void beforetextchanged(charsequence s, int start, int count,                 int after) {              // todo auto-generated method stub         }          @override         public void aftertextchanged(editable s) {             // todo auto-generated method stub          }     }); } 

simple that.