Question

i have in my android main.xml file as the following..
when i run it is showing some exception but in main.xml in graphical view it is not showing any error..
follwing is my code inside Linearlayout

      <ScrollView android:id="@+id/ScrollView01" 
        android:layout_width="fill_parent" 
        android:layout_height="match_parent">

          <LinearLayout
            android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_gravity="top"
            android:layout_height="match_parent">       

              <TextView android:layout_width="fill_parent"
                       android:layout_height="wrap_content"
                       android:layout_gravity="center"
                       android:text="UserName"/>

               <EditText android:id="@+id/username"
                       android:layout_width="fill_parent"
                       android:layout_height="wrap_content"
                       android:text=""/>                              
           <Button
               android:id="@+id/login_button"
               android:layout_width="60dp"
               android:layout_height="30dp"
               android:text="login"/>
        </LinearLayout>

         <LinearLayout
            android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_gravity="top"
            android:layout_height="match_parent">       

              <TextView android:layout_width="fill_parent"
                       android:layout_height="wrap_content"
                       android:layout_gravity="center"
                       android:text=""/>

               <EditText android:layout_width="fill_parent"
                       android:layout_height="wrap_content"
                       android:text=""/>                              
           <Button
               android:layout_width="60dp"
               android:layout_height="30dp"
               android:text="@string/login_btn"/>
        </LinearLayout>
    </ScrollView>

Answer 1

ScrollView should have ONLY ONE child. in ur example u have placed 2 linear layouts inside scrollview which is causing error..
place the 2 linear layouts inside 1 linear layout and place the whole thing in scrollview. it will work..

    <ScrollView android:id="@+id/ScrollView01" 
        android:layout_width="fill_parent" 
        android:layout_height="match_parent">
             <LinearLayout
            android:orientation="vertical"
            android:layout_width="fill_parent"
            android:layout_gravity="top"
            android:layout_height="match_parent">  
                      <LinearLayout
                        android:orientation="vertical"
                        android:layout_width="fill_parent"
                        android:layout_gravity="top"
                        android:layout_height="match_parent">       

                          <TextView android:layout_width="fill_parent"
                                   android:layout_height="wrap_content"
                                   android:layout_gravity="center"
                                   android:text="@string/UserNameText"/>

                           <EditText
                                   android:id="@+id/username"
                                   android:layout_width="fill_parent"
                                   android:layout_height="wrap_content"
                                   android:text="@string/UserNameText"/>                              
                       <Button
                           android:id="@+id/login_button"
                           android:layout_width="60dp"
                           android:layout_height="30dp"
                           android:text="@string/login_btn"/>
                    </LinearLayout>

                     <LinearLayout
                        android:orientation="vertical"
                        android:layout_width="fill_parent"
                        android:layout_gravity="top"
                        android:layout_height="match_parent">       

                          <TextView android:layout_width="fill_parent"
                                   android:layout_height="wrap_content"
                                   android:layout_gravity="center"
                                   android:text="@string/UserNameText"/>

                           <EditText
                                   android:id="@+id/username"
                                   android:layout_width="fill_parent"
                                   android:layout_height="wrap_content"
                                   android:text="@string/UserNameText"/>                              
                       <Button
                           android:id="@+id/login_button"
                           android:layout_width="60dp"
                           android:layout_height="30dp"
                           android:text="@string/login_btn"/>
                    </LinearLayout>
        </LinearLayout>
    </ScrollView>