android check редактировать текстовое поле

Question

Хорошо, как я могу настроить проверку прав на текстовое поле, чтобы ограничить ввод определенных символов и длины.

Ниже то, что я работал над но если курсор находится в первом положении, и я ударил вернуть разбился

final EditText editText1 = (EditText)findViewById(R.id.editText9); 
    editText1.setLayoutParams(new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.WRAP_CONTENT, 
      RelativeLayout.LayoutParams.WRAP_CONTENT)); 
    editText1.setText("a"); 
    editText1.setTag(1); 
    editText1.setId(idedittext1); 
    editText1.setBackgroundColor(0xff66ff66); 
    editText1.setPadding(20, 20, 20, 20);// in pixels (left, top, right, bottom) 
    //linear1.addView(editText1); 
    final String matchCharacters = "abcdefghijklmnopqrstuvwxyz."; 
    final CharSequence s_saved = ""; 
    editText1.addTextChangedListener(new TextWatcher() 
    { 

     public void onTextChanged(CharSequence s, int start, int before, int count) 
     { 

      System.out.println("------------------------------------------------------------"); 
      System.out.println("Entry: " + s + " " + s.length() + " " + start + " " + before + " " + count); 

      if (before == 1) 
      { 
       System.out.println("return"); 
      } 


      if (s.length() > 4) 
      { 
        System.out.println("onTextChanged >4 replaced : " + s + " " + start + " " + before + " " + count); 
        String replaceStr = s.toString().substring(0, s.length() - 1); 
        editText1.setText(replaceStr); 
        editText1.setSelection(s.length() - 1); 
      } 


      if (s.length() > 0 && before != 1) 
      { 
        Integer sfound = 0; 
        String sstr = s.toString(); 
        char[] sArray = sstr.toCharArray(); 
        char[] mArray = matchCharacters.toCharArray(); 
        System.out.println("sarray-marray " + " " + sstr + "-" + matchCharacters); 
        for (char sc : sArray) { 
         System.out.println("It worked1 " + sc); 
         for (char mc : mArray) { 
          System.out.println("It worked2 " + " " + sc + "-" + mc); 
          if (sc == mc) { 
           //System.out.println("It worked!"); 
           sfound = sfound + 1; 
          } else { 
           //System.out.println("It did not work!"); 
          } 
         } 
        } 
        System.out.println("slength-sfound " + " " + s.length() + "-" + sfound); 
        if (s.length() == sfound) { 
         System.out.println("MATCHED!"); 
        } else { 
         System.out.println("NOMATCH!"); 
         String replaceStr = s.toString().substring(0, s.length() - 1); 
         editText1.setText(replaceStr); 
         editText1.setSelection(s.length() - 1); 


         AlertDialog alertDialog = new AlertDialog.Builder(MainActivity.this).create(); 
         alertDialog.setTitle("Alert"); 
         alertDialog.setMessage("Your can only enter the following characters: " + matchCharacters); 
         alertDialog.setButton(AlertDialog.BUTTON_NEUTRAL, "OK", 
           new DialogInterface.OnClickListener() { 
            public void onClick(DialogInterface dialog, int which) { 
             dialog.dismiss(); 
            } 
           }); 
         alertDialog.show(); 
        } 
      } 
     } 

Любая помощь приветствуется. Благодаря

Answer 1

Чтобы ограничить длину EditText

<EditText 
    android:id="@+id/edit_text" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content" 
    android:maxLength="10"/> 

Чтобы предотвратить определенный символ из набираясь в

final EditText editText = (EditText) findViewById(R.id.edit_text); 
    final String matchCharacters = "aeiou"; 
    editText.addTextChangedListener(new TextWatcher() { 
     @Override 
     public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {} 

     @Override 
     public void onTextChanged(CharSequence charSequence, int i, int i1, int i2) {} 

     @Override 
     public void afterTextChanged(Editable editable) { 
      String text = String.valueOf(editText.getText()); 
      boolean edited = false; 
      for(int i=0; i<matchCharacters.length(); i++){ 
       char toPrevent = matchCharacters.charAt(i); 
       if(text.indexOf(toPrevent) < 0){ 
        continue; 
       } 

       text = text.replace(String.valueOf(toPrevent), ""); 
       edited = true; 
      } 

      if(edited){ 
       editText.setText(text); 
      } 
     } 
    });