withDrawcet.addTextChangedListener(new TextWatcher() {
            @Override
            public void beforeTextChanged(CharSequence charSequence, int i, int i1, int i2) {

            }

            @Override
            public void onTextChanged(CharSequence s, int i, int i1, int i2) {
                if (s.toString
 
().contains(".")) {
                    if (s.length() - 1 - s.toString().indexOf(".") > 2) {
                        s = s.toString().subSequence(0,
                                s.toString().indexOf(".") + 3);
                        withDrawcet.setText(s);
                        withDrawcet.setSelection
 
(s.length());
                    }
                }
                if (s.toString().trim().substring(0).equals(".")) {
                    s = "0" + s;
                    withDrawcet.setText(s);
                    withDrawcet.setSelection(2);
                }

                if (s.toString().startsWith
 
("0")
                        && s.toString().trim().length() > 1) {
                    if (!s.toString().substring(1, 2).equals(".")) {
                        withDrawcet.setText(s.subSequence(0, 1));
                        withDrawcet.setSelection(1);
                        return;
                    }
                }
            }

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