Вторая кнопка в андроиде невидима

Question

In the activity_main.xml is used 
- ScrollView 
- LinearLayout 
- RelativeLayout 

Для TextView, RadioGroups, RadioButtons, EditText и Button с. Приложение функционировало нормально до resetButton добавлен. После этого приложения работает, но resetButton невидимо. Я думаю, что есть ошибка между макетами, может быть, я должен использовать другую комбинацию макетов, я не знаю. Спасибо за любую помощь!

**activity_layout.xml** 


    <?xml version="1.0" encoding="utf-8"?> 
    <ScrollView 
     xmlns:android="http://schemas.android.com/apk/res/android" 
     xmlns:tools="http://schemas.android.com/tools" 
     android:layout_width="match_parent" 
     android:layout_height="match_parent" 
     tools:context="com.allyouask.hungryforhistory.MainActivity"> 

     <LinearLayout 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 
     <RelativeLayout 
      android:layout_width="wrap_content" 
      android:layout_height="match_parent"> 

      <TextView 
       android:id="@+id/welcomeMessage" 
       android:layout_height="wrap_content" 
       android:layout_width="wrap_content" 
       style="@style/welcomeMessage" 
       android:fontFamily="sans-serif-light" 
       android:text="Welcome to Hungry For History!\n   Let's get started!" 
       android:layout_centerHorizontal="true"/> 

      <TextView 
       android:id="@+id/inputQuestion" 
       android:layout_height="wrap_content" 
       android:layout_width="wrap_content" 
       style="@style/QuestionsStyle" 
       android:text=" Who was the king of the Gods in Ancient Greece:" 
       android:layout_below="@+id/welcomeMessage"/> 

      <EditText 
       android:id="@+id/inputAnswer" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:layout_below="@id/inputQuestion"/> 

      <TextView 
       android:id="@+id/firstQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/inputAnswer" 
       android:paddingLeft="5dp" 
       android:text="Who was born in Ancient City Stagira, Greece?"/> 


      <RadioGroup 
       android:id="@+id/firstGroupRadioButtons" 
       android:layout_below="@+id/firstQuestion" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:orientation="horizontal"/> 

      <RadioButton 
       android:id="@+id/firstLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/firstGroupRadioButtons" 
       android:text="Aristotle" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/firstRightRadioButton" 
       android:layout_below="@+id/firstGroupRadioButtons" 
       style="@style/RadioButtonStyle" 
       android:layout_toRightOf="@+id/firstLeftRadioButton" 
       android:text="Pythagoras" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/secondQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/firstLeftRadioButton" 
       android:paddingLeft="5dp" 
       android:text="Who said in his last speech:With malice toward none;...let us strive on to finish the work we are in;to bind up the nation's wounds;into care for him who shall have borne the battle and for his widow and his orphans?"/> 

      <RadioGroup 
       android:id="@+id/secondGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@id/secondQuestion" 
       android:orientation="horizontal"/> 
      <RadioButton 
       android:id="@+id/secondLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_alignParentLeft="true" 
       android:layout_below="@+id/secondGroupRadioButtons" 
       android:text="William McKinley" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/secondRightRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/secondGroupRadioButtons" 
       android:layout_toRightOf="@+id/secondLeftRadioButton" 
       android:text="Abraham Lincoln" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/thirdQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_below="@+id/secondLeftRadioButton" 
       android:paddingLeft="5dp" 
       android:text="Where the An Lushan Rebellion took place?"/> 

      <RadioGroup 
       android:id="@+id/thirdGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/thirdQuestion" 
       android:orientation="horizontal"/> 

      <RadioButton 
       android:id="@+id/thirdLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/thirdGroupRadioButtons" 
       android:text="China" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/thirdRightRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/thirdGroupRadioButtons" 
       android:layout_toRightOf="@+id/thirdLeftRadioButton" 
       android:text="Thailand" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/fourthQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_below="@+id/thirdLeftRadioButton" 
       android:text="Who was the most famous exemplar of absolute monarchy in France?"/> 


      <RadioGroup 
       android:id="@+id/fourthGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/fourthQuestion" 
       android:orientation="horizontal"/> 

      <RadioButton 
       android:id="@+id/fourthLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/fourthGroupRadioButtons" 
       android:text="Louis XIV" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/fourthRightCheckBox" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/fourthGroupRadioButtons" 
       android:layout_toRightOf="@+id/fourthLeftRadioButton" 
       android:text="Michael I" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/fifthQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_below="@+id/fourthLeftRadioButton" 
       android:text="When Alexander The Great lived?"/> 

      <RadioGroup 
       android:id="@+id/fifthGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@id/fifthQuestion" 
       android:orientation="horizontal"/> 

      <RadioButton 
       android:id="@+id/fifthLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/fifthGroupRadioButtons" 
       android:text="330-323 BC" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/fifthRightRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/fifthGroupRadioButtons" 
       android:layout_toRightOf="@+id/fifthLeftRadioButton" 
       android:text="336-323 BC" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/sixthQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_below="@+id/fifthLeftRadioButton" 
       android:text="Where Albert Einstein studied?"/> 

      <RadioGroup 
       android:id="@+id/sixthGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@id/sixthQuestion" 
       android:orientation="horizontal"/> 

      <RadioButton 
       android:id="@+id/sixthLeftRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/sixthGroupRadioButtons" 
       android:text="University of Zurich" 
       android:onClick="onRadioButtonClicked"/> 

      <RadioButton 
       android:id="@+id/sixthRightRadioButton" 
       style="@style/RadioButtonStyle" 
       android:layout_below="@+id/sixthGroupRadioButtons" 
       android:layout_toRightOf="@+id/sixthLeftRadioButton" 
       android:text="University of Germany" 
       android:onClick="onRadioButtonClicked"/> 

      <TextView 
       android:id="@+id/seventhQuestion" 
       style="@style/QuestionsStyle" 
       android:layout_below="@+id/sixthLeftRadioButton" 
       android:text="What was the main interest of Democritus?"/> 

      <RadioGroup 
       android:id="@+id/seventhGroupRadioButtons" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/seventhQuestion" 
       android:orientation="horizontal"> 

       <RadioButton 
        android:id="@+id/seventhLeftRadioButton" 
        style="@style/RadioButtonStyle" 
        android:layout_below="@+id/seventhGroupRadioButtons" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:text="Mathematics-Astronomy" 
        android:onClick="onRadioButtonClicked"/> 

       <RadioButton 
        android:id="@+id/seventhRightRadioButton" 
        style="@style/RadioButtonStyle" 
        android:layout_below="@+id/seventhGroupRadioButtons" 
        android:layout_toRightOf="@+id/seventhLeftRadioButtons" 
        android:layout_width="wrap_content" 
        android:layout_height="wrap_content" 
        android:text="Philosophy-Psychology" 
        android:onClick="onRadioButtonClicked"/> 
      </RadioGroup> 

      <Button 
       android:id="@+id/submitButton" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:background="@color/backgroundColor" 
       android:layout_marginBottom="4dp" 
       android:text="Submit" 
       android:textColor="@color/textColor" 
       android:onClick="OnClick" 
       android:layout_alignParentBottom="true"/> 

      <Button 
       android:id="@+id/resetButton" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:layout_marginTop="2dp" 
       android:layout_marginBottom="3dp" 
       android:onClick="OnClick" 
       android:background="@color/backgroundResetColor" 
       android:textColor="@color/textColor" 
       android:text="Reset" 
       android:textAllCaps="true" 
       android:layout_below="@+id/submitButton"/> 
     </RelativeLayout> 
     </LinearLayout> 
    </ScrollView> 

    styles.xml 
    <resources> 

     <!-- Base application theme. --> 
     <style name="AppTheme" parent="Theme.AppCompat.Light.DarkActionBar"> 
      <!-- Customize your theme here. --> 
      <item name="colorPrimary">#FFC107</item> 
      <item name="colorPrimaryDark">#E65100</item> 
      <item name="colorAccent">#EF6C00</item> 
     </style> 

     <style name="welcomeMessage"> 
      <item name="android:layout_width">wrap_content</item> 
      <item name="android:layout_height">wrap_content</item> 
      <item name="android:layout_centerHorizontal">true</item> 
       <item name="android:paddingTop">10dp</item> 
       <item name="android:paddingBottom">10dp</item> 
      <item name="android:textSize">16sp</item> 
      <item name="android:textStyle">normal</item> 
      <item name="android:textColor">#EF6C00</item> 
     </style> 

     <style name="QuestionsStyle"> 
      <item name="android:layout_width">wrap_content</item> 
      <item name="android:layout_height">wrap_content</item> 
      <item name="android:paddingLeft">6dp</item> 
      <item name="android:paddingRight">6dp</item> 
      <item name="android:textSize">15sp</item> 
      <item name="android:textStyle">italic</item> 
      <item name="android:textColor">#000000</item> 
     </style> 

     <style name="RadioButtonStyle"> 
     <item name="android:textSize">14sp</item> 
      <item name="android:textColor">#FFAB00</item> 
      <item name="android:layout_width">wrap_content</item> 
      <item name="android:layout_height">wrap_content</item> 
      <item name="android:textStyle">bold</item> 
      <item name="android:paddingLeft">6dp</item> 

     </style> 

colors.xml 
    <?xml version="1.0" encoding="utf-8"?> 
<resources> 
    <color name="colorPrimary">#FFC107</color> 
    <color name="colorPrimaryDark">#E65100</color> 
    <color name="colorAccent">#EF6C00</color> 

    <!-- Button Colors --> 
<color name="backgroundColor">#EF6C00</color> 
    <color name="backgroundResetColor">#FB8C00</color> 
    <color name="textColor">#FFFFFF</color> 
</resources>  



     </resources> 

Answer 1

Используя ваш код, я получаю этот выход. Вы хотите это или что-то еще. я поставил код внутри этого

<ScrollView 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content"> 

     <RelativeLayout 
      android:layout_width="match_parent" 
      android:layout_height="match_parent"> 

     // your code here.. 

     </RelativeLayout> 

    </ScrollView> 

'

ОБНОВЛЕНИЕ:

вы должны дать id этот путь .. и проверить layout_below свойство как Button.

<Button 
       android:id="@+id/submitButton" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/seventhGroupRadioButtons" 
       android:layout_marginBottom="4dp" 
       android:layout_marginTop="10dp" 
       android:background="@android:color/black" 
       android:onClick="OnClick" 
       android:text="Submit" 
       android:textColor="@android:color/white" /> 

      <Button 
       android:id="@+id/resetButton" 
       android:layout_width="match_parent" 
       android:layout_height="wrap_content" 
       android:layout_below="@+id/submitButton" 
       android:layout_marginBottom="3dp" 
       android:layout_marginTop="2dp" 
       android:onClick="OnClick" 
       android:text="Reset" 
       android:textAllCaps="true" 
       android:textColor="@android:color/black" />