android - layout_weight doesn't take effect -

i'm trying split vertical space between views evenly using layout_weight reason doesn't work. followed this answer , still views's spaces aren't effected that. doing wrong?

<linearlayout                 android:layout_width="match_parent"                 android:layout_height="match_parent"                 android:orientation="vertical">                  <space                     android:layout_width="1dp"                     android:layout_height="0dp"                     android:layout_weight="1" >                 </space>                  <android.support.design.widget.textinputlayout                     android:layout_width="match_parent"                     android:layout_height="wrap_content">                      <autocompletetextview                         android:background="@drawable/rounded_corners_white"                         android:id="@+id/email"                         android:paddingend="16dp"                         android:paddingstart="16dp"                         android:layout_marginright="16dp"                         android:layout_marginleft="16dp"                         android:layout_height="40dp"                         android:layout_width="match_parent"                         android:inputtype="textemailaddress"                         android:maxlines="1"                         android:singleline="true" />                  </android.support.design.widget.textinputlayout>                  <space                     android:layout_width="1dp"                     android:layout_height="0dp"                     android:layout_weight="1" >                 </space>                  <android.support.design.widget.textinputlayout                     android:layout_width="match_parent"                     android:layout_height="wrap_content">                  <edittext                     android:id="@+id/password"                     android:layout_width="match_parent"                     android:layout_marginright="16dp"                     android:layout_marginleft="16dp"                     android:paddingend="16dp"                     android:paddingstart="16dp"                     android:layout_height="40dp"                     android:background="@drawable/rounded_corners_white"                     android:imeactionid="@+id/login"                     android:imeactionlabel="@string/action_sign_in_short"                     android:imeoptions="actionunspecified"                     android:inputtype="textpassword"                     android:maxlines="1"                     android:singleline="true" />                 </android.support.design.widget.textinputlayout>                  <space                     android:layout_width="1dp"                     android:layout_height="0dp"                     android:layout_weight="1" >                 </space>                  <view                     android:layout_margintop="30dp"                     android:layout_marginbottom="30dp"                     android:layout_marginright="15dp"                     android:layout_marginleft="15dp"                     android:layout_width="match_parent"                     android:layout_height="3dp"                     android:background="@drawable/rounded_corners_white" />                  <space                     android:layout_width="1dp"                     android:layout_height="0dp"                     android:layout_weight="1" >                 </space>                  <button                     android:id="@+id/sign_in_button"                     android:layout_width="match_parent"                     android:layout_height="40dp"                     android:layout_marginright="16dp"                     android:layout_marginleft="16dp"                     style="?android:textappearancesmall"/>             </linearlayout> 

update: if image not shown (http://i.stack.imgur.com/mqalm.png) [

just add below line linearlayout:

android:weightsum="4"