editText.setOnKeyListener(new OnKeyListener() {
   @Override
   public boolean onKey(View v, int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_DEL
      && event.getAction() == KeyEvent.ACTION_DOWN) {
     //TODO:
     return true;
    }
    return false;
   }
  });

android:maxLength="6"

public class VerifyCodeView extends RelativeLayout {
 private EditText editText;
 private TextView[] textViews;
 private static int MAX = 6;
 private String inputContent;

 public VerifyCodeView(Context context) {
  this(context, null);
 }

 public VerifyCodeView(Context context, AttributeSet attrs) {
  this(context, attrs, 0);
 }

 public VerifyCodeView(Context context, AttributeSet attrs, int defStyleAttr) {
  super(context, attrs, defStyleAttr);
  View.inflate(context, R.layout.view_verify_code, this);

  textViews = new TextView[MAX];
  textViews[0] = (TextView) findViewById(R.id.item_code_iv0);
  textViews[1] = (TextView) findViewById(R.id.item_code_iv1);
  textViews[2] = (TextView) findViewById(R.id.item_code_iv2);
  textViews[3] = (TextView) findViewById(R.id.item_code_iv3);
  textViews[4] = (TextView) findViewById(R.id.item_code_iv4);
  textViews[5] = (TextView) findViewById(R.id.item_code_iv5);
  editText = (EditText) findViewById(R.id.item_edittext);

  editText.setCursorVisible(false);//隐藏光标
  setEditTextListener();
 }

 private void setEditTextListener() {
  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) {
    inputContent = editText.getText().toString();

    if (inputCompleteListener != null) {
     if (inputContent.length() >= MAX) {
      inputCompleteListener.inputComplete();
     } else {
      inputCompleteListener.invalidContent();
     }
    }

    for (int i = 0; i < MAX; i++) {
     if (i < inputContent.length()) {
      textViews[i].setText(String.valueOf(inputContent.charAt(i)));
     } else {
      textViews[i].setText("");
     }
    }
   }
  });
 }


 private InputCompleteListener inputCompleteListener;

 public void setInputCompleteListener(InputCompleteListener inputCompleteListener) {
  this.inputCompleteListener = inputCompleteListener;
 }

 public interface InputCompleteListener {

  void inputComplete();

  void invalidContent();
 }

 public String getEditContent() {
  return inputContent;
 }

}