验证码输入错误清空输入框

```java
 /**
     * 清空验证码输入框
     */
    public void setEmpty() {
        EditText editText;
        for (int i = mEtNumber - 1; i >= 0; i--) {
            editText = (EditText) getChildAt(i);
            editText.setText("");
            if (i == 0) {
                editText.setCursorVisible(true);
                editText.requestFocus();
            }
        }
    }
```