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) {
//长度发生变化,监听到输入的长度为 editText.getText().length()
textView.setText(String.valueOf(editText.getText().length()) + "/10");
}
});