In Android, how to make Login button disable with respect to EditText?

Question

If EditText is empty then Login Button has to be disabled. And if EditText has some texts then Login Button has to be ena

Answer 1

You need to attach a TextWatcher that is called whenever the text in one of the EditText fields is changed.

private EditText mName;
private EditText mPassword;
private Button mButton;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_login_check);
    mName = (EditText) findViewById(R.id.editText1);
    mPassword = (EditText) findViewById(R.id.editText2);
    mButton = (Button) findViewById(R.id.button1);

    mName.addTextChangedListener(mWatcher);
    mPassword.addTextChangedListener(mWatcher);
}

private TextWatcher mWatcher = new TextWatcher() {
    @Override
    public void afterTextChanged(Editable s) {
        boolean nameNotEmpty = mName.getText().length()>0;
        boolean pwNotEmpty = mPassword.getText().length()>0;
        mButton.setEnabled(nameNotEmpty && pwNotEmpty);
    }
    @Override
    public void beforeTextChanged(CharSequence s, int start, int count, int after) {}
    @Override
    public void onTextChanged(CharSequence s, int start, int before, int count) {}
};

Answer 2

try this

  if(s1.equals("") && s2.equals(""))
    {
        b.setEnabled(true);
        // to change color of the button you need to apply style to the button[here refer custom bg][1]
    }
    else
    {
        b.setEnabled(false);
       //do nothing or display toast msg
    }

Answer 3

I only want to add that the check will NOT work if the InputType of the EditText is a password (or similar) and the fuction to proof the length of the text (see other answers) is called from

@Override
public void onTextChanged(CharSequence s, int start, int before, int count) {...}

So it is important to call the check from

@Override 
public void afterTextChanged(Editable s) {...}

Answer 4

try this:

EditText et1,et2;
Button b;

@Override
protected void onCreate(Bundle savedInstanceState) {

  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_login_check);
  et1 = (EditText) findViewById(R.id.editText1);
  et2 = (EditText) findViewById(R.id.editText2);
  b = (Button) findViewById(R.id.button1);


  et1.addTextChangedListener(new TextWatcher() {

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

                            String s1 = et1.getText().toString();
                            String s2 = et2.getText().toString();

                             if(s1.equals("") && s2.equals("")){
                                   b.setEnabled(false);
                            } 
                            else if(!s1.equals("")&&s2.equals("")){
                                   b.setEnabled(false);
                            }
                            else if(!s2.equals("")&&s1.equals(""){
                                   b.setEnabled(false);
                            }
                            else {
                            b.setEnabled(true);
                          }

        }

        @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

        }
    });
  et2.addTextChangedListener(new TextWatcher() {

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

                            String s1 = et1.getText().toString();
                            String s2 = et2.getText().toString();

                            if(s1.equals("") && s2.equals("")){
                                   b.setEnabled(false);
                            } 
                            else if(!s1.equals("")&&s2.equals("")){
                                   b.setEnabled(false);
                            }
                            else if(!s2.equals("")&&s1.equals(""){
                                   b.setEnabled(false);
                            }
                            else {
                            b.setEnabled(true);
                          }

        }

        @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

        }
    });

}

Answer 5

private TextWatcher mPhoneNumberEtWatcher = 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) {
        if (charSequence.length() >= 10) {
            mPhoneImg.setImageDrawable(getResources().getDrawable(R.drawable.phone_activate));

            if (mPasswordEt.getText().toString().length() >= 5) {
                mLoginBtn.setEnabled(true);
            }

        } else {
            mPhoneImg.setImageDrawable(getResources().getDrawable(R.drawable.phone));
            mLoginBtn.setEnabled(false);
        }
    }

    @Override
    public void afterTextChanged(Editable editable) {
    }
};

mPhoneNumberEt.addTextChangedListener(mPhoneNumberEtWatcher);

You should use TextWatcher. That will call method after typing of user. And you can check length and somthing else of your edit text.

Answer 6

You need to implement TextWatcher on EditText to achieve the result.

EditText et1, et2;
Button b;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    et1 = (EditText) findViewById(R.id.editText1);
    et2 = (EditText) findViewById(R.id.editText2);
    b = (Button) findViewById(R.id.button1);

    checkValidation();

    et1.addTextChangedListener(mWatcher);
    et2.addTextChangedListener(mWatcher);
}

private void checkValidation() {
    // TODO Auto-generated method stub

    if ((TextUtils.isEmpty(et1.getText()))
            || (TextUtils.isEmpty(et2.getText())))
        b.setEnabled(false);
    else
        b.setEnabled(true);

}

TextWatcher mWatcher = new TextWatcher() {

    @Override
    public void onTextChanged(CharSequence s, int start, int before,
            int count) {
        // TODO Auto-generated method stub
        checkValidation();
    }

    @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

    }
};