How to center the content inside a linear layout?

Question

I\'m trying to center an ImageView inside a LinearLayout horizontally and vertically, but I just can\'t do it. The main reason why I\'m not using a

Answer 1

android:gravity handles the alignment of its children,

android:layout_gravity handles the alignment of itself.

So use one of these.

<LinearLayout 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"
    android:background="#000"
    android:baselineAligned="false"
    android:gravity="center"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_weight="1"
        android:gravity="center" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

or

<LinearLayout 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"
    android:background="#000"
    android:baselineAligned="false"
    android:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".Main" >

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_speak"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_speak" />
    </LinearLayout>

    <LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" >

        <ImageView
            android:id="@+id/imageButton_readtext"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            android:background="@drawable/image_bg"
            android:src="@drawable/ic_readtext" />
    </LinearLayout>

    ...
</LinearLayout>

Answer 2

android:gravity can be used on a Layout to align its children.

android:layout_gravity can be used on any view to align itself in its parent.

NOTE: If self or children is not centering as expected, check if width/height is match_parent and change to something else

Answer 3

Here's some sample code. This worked for me.

<LinearLayout
    android:gravity="center"
    >
    <TextView
        android:layout_gravity="center"
        />
    <Button
        android:layout_gravity="center"
        />
</LinearLayout>

So you're designing the Linear Layout to place all its contents (TextView and Button) in its center, and then the TextView and Button are placed relative to the center of the Linear Layout.

Answer 4

android:layout_gravity is used for the layout itself

Use android:gravity="center" for children of your LinearLayout

So your code should be:

<LinearLayout
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:gravity="center"
        android:layout_weight="1" >

Answer 5

If you are looking for an answer in java code,

LinearLayout linearLayout = new LinearLayout(context);
linearLayout.setGravity(Gravity.CENTER);
// add children

Answer 6

I tried solutions mentioned here but It didn't help me. I mind the solution is layout_width have to use wrap_content as value.

<LinearLayout
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:gravity="center"
    android:layout_weight="1" >