解决合并

app/src/main/res/layout/activity_login.xml

@@ -4,6 +4,7 @@
     xmlns:tools="http://schemas.android.com/tools"
     android:layout_width="match_parent"
     android:layout_height="match_parent"
+    android:background="@mipmap/bg"
     tools:context="activity.LoginActivity">
 
     <TextView

app/src/main/res/layout/fragment_forget_paw.xml

@@ -4,6 +4,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:background="@mipmap/bg"
     tools:context=".fragment.ForgetPawFragment">
     <include layout="@layout/register_title" android:id="@+id/forgetPaw"/>
     <TextView

app/src/main/res/layout/fragment_register.xml

@@ -4,6 +4,7 @@
     android:layout_width="match_parent"
     android:layout_height="match_parent"
     xmlns:app="http://schemas.android.com/apk/res-auto"
+    android:background="@mipmap/bg"
     tools:context=".fragment.RegisterFragment">
 
     <include layout="@layout/register_title"