多个edittext共同使用一个TextWatcher

@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.app_register);
 

tvTimeToReget=(TextView)findViewById(R.id.appr_textview_time_to_reget);
btnReget=(Button)findViewById(R.id.appr_btn_reget);
btnReget.setOnClickListener(this);


btnTitleBack=(Button)findViewById(R.id.app_title_btn_left);
btnTitleBack.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
sendEmptyMessage(2);
}
});
setCurrRegisterView(STATUS_NUM_MODULE);

etMobileNum =(EditText)findViewById(R.id.appr_edittext_mobile_num);
etMobileNum.addTextChangedListener(new CustomTextWatcher(etMobileNum));


etVerifyCode=(EditText)findViewById(R.id.appr_edittext_verify_code);
etVerifyCode.addTextChangedListener(new CustomTextWatcher(etVerifyCode));


etPassword=(EditText)findViewById(R.id.appr_edittext_password);
etRePassword=(EditText)findViewById(R.id.appr_edittext_rePassword);
}


private class CustomTextWatcher implements TextWatcher {
private EditText mEditText;
private CharSequence mCharSequence;
public CustomTextWatcher(EditText e) {
mEditText = e;
}


public void beforeTextChanged(CharSequence s, int start, int count, int after) {
mCharSequence = s;
}


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


}


public void afterTextChanged(Editable s) {
if (mCharSequence.length() ==1) {
btnRegisterNextStep.setBackgroundResource(R.drawable.register_button_selector);


}else if(mCharSequence.length()<1) {
btnRegisterNextStep.setBackgroundResource(R.drawable.register_button_not_available);
}
}
}