How to set this layout?

I am going to implement the Calculator type application. In that I have set the Different but开发者_如何学Cton as like below code:

<RelativeLayout android:id="@+id/linear_layout" android:layout_width="wrap_content"
            android:layout_height="wrap_content" android:orientation="vertical"
            android:layout_centerInParent="true" android:gravity="center_horizontal">

            <!-- First row Start -->

                <Button android:id="@+id/sevenNumber" 
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="7" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>

                <Button android:id="@+id/eightNumber" android:layout_toRightOf="@+id/sevenNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="8" android:textColor="#ffffff" android:textSize="22dp"
                    android:background="@drawable/selector_button"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"/>

                <Button android:id="@+id/nineNumber" android:layout_toRightOf="@+id/eightNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="9" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>    

                <Button android:id="@+id/acButton" android:layout_toRightOf="@+id/nineNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="AC" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/brown_button"/>

            <!-- First row Finish -->

            <!-- Second row Start -->

                <Button android:id="@+id/fourNumber" android:layout_below="@+id/sevenNumber" 
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="4" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>

                <Button android:id="@+id/fiveNumber" android:layout_toRightOf="@+id/fourNumber" android:layout_below="@+id/eightNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="5" android:textColor="#ffffff" android:textSize="22dp"
                    android:background="@drawable/selector_button"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"/>

                <Button android:id="@+id/sixNumber" android:layout_toRightOf="@+id/fiveNumber" android:layout_below="@+id/nineNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="6" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>    

                <Button android:id="@+id/crearButton" android:layout_toRightOf="@+id/sixNumber" android:layout_below="@+id/acButton"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="C" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/brown_button"/>

            <!-- Second row finish -->

            <!-- Third row Start -->


                <Button android:id="@+id/firstNumber" android:layout_below="@+id/fourNumber" 
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="1" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>

                <Button android:id="@+id/secondNumber" android:layout_toRightOf="@+id/firstNumber" android:layout_below="@+id/fiveNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="2" android:textColor="#ffffff" android:textSize="22dp"
                    android:background="@drawable/selector_button"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"/>

                <Button android:id="@+id/threeNumber" android:layout_toRightOf="@+id/secondNumber" android:layout_below="@+id/sixNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="3" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>    



            <!-- Third row finish -->

            <!-- Fourth row Start -->


                <Button android:id="@+id/zeroNumber" android:layout_below="@+id/firstNumber"
                    android:layout_height="wrap_content" android:layout_width="110dp"
                    android:text="0" android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:background="@drawable/selector_button"/>

                <Button android:id="@+id/dotNumber" android:layout_toRightOf="@+id/zeroNumber" android:layout_below="@+id/threeNumber"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:text="." android:textColor="#ffffff" android:textSize="22dp"
                    android:background="@drawable/selector_button"
                    android:layout_marginTop="5dp" android:layout_marginBottom="5dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"/>

                <Button android:id="@+id/doNothing" android:layout_toRightOf="@+id/threeNumber" android:layout_below="@+id/crearButton"
                    android:layout_height="wrap_content" android:layout_width="50dp"
                    android:textColor="#ffffff" android:textSize="22dp"
                    android:layout_marginLeft="5dp" android:layout_marginRight="5dp"
                    android:layout_marginTop="5dp" android:background="@drawable/do_nothing_button" android:layout_alignBottom="@+id/dotNumber"/>

            <!-- Third row finish -->

        </RelativeLayout>

Now, rightnow i have set the first row of Linearlayout as android:gravity="center_horizontal" which contain the button like "7","8","9" and "AC" button. But i want it to set autometicaly to fit with the device width. I think i have to use the weight property. but where and How i have to use it that i dont know So Please Help me regardin it. Thanks.

---

use the weightSum property in your layout tag and in your buttons tag also. Set it to 1 in your layout tag and divide it in the way you want to set your button and set this value to button like if you want 4 buttons to be displayed with equal proportion then 1/4=0.25, set 0.25 to each button tag.

Refer this and this.

---

Remove android:layout_centerInParent="true" from LinearLayout.
Set android:layout_width="fill_parent" for LinearLayout and Buttons.
Try setting android:layout_weight="1" for every Button.

---

First Set your LinearLayout width as fill_parent, and remove the gravity , and also put android:layout_weight=1 for each of your children to share the equal width. set layout_width parameter of each of the children to 0dp