错误：(2)解析XML时出错：XML或文本声明不在实体android studio的开头

Error:(2) Error parsing XML: XML or text declaration not at start of entity

Error:Execution failed for task ‘:app:processDebugResources’.
com.android.ide.common.process.ProcessException: org.gradle.process.internal.ExecException: Process ‘command ‘C:\Users\ahmad\AppData\Local\Android\sdk\build-tools\21.1.2\aapt.exe” finished with non-zero exit value 1

这是代码：

<?xml version="1.0" encoding="utf-8"?>
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:padding="6dip" >
<TextView
    android:id="@+id/userid"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:paddingTop="6dip"
    android:paddingLeft="6dip"
    android:textSize="17sp"
    android:textStyle="bold"
    android:visibility="gone"
    />
<CheckBox
    android:id="@+id/checkBox1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:focusable="false"
    android:focusableInTouchMode="false"
    android:text="CheckBox" />
<TextView
    android:id="@+id/fullname"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignBaseline="@+id/checkBox1"
    android:layout_alignBottom="@+id/checkBox1"
    android:layout_toRightOf="@+id/checkBox1"
    android:text="TextView" />
 </RelativeLayout>

<?xml version="1.0" encoding="utf-8"?>

您在文件顶部有两个.删除一个,该错误应该消失.