Is there a way to offset a view from center in And

问题:

im trying to possition my button not exactly in center, but lets say in the 2/5s of the screen height, i was looking for attribute unsuccessfully, so i tried this approach

<RelativeLayout 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="@drawable/background"
android:padding="20dp" >

 <ImageButton
    android:id="@+id/flashlight_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_above="@+id/fakeView"
    android:background="@null"
    android:contentDescription="@string/flashlight_button_description"
    android:src="@drawable/freeml_bright" />

   <View
    android:id="@+id/fakeView"
    android:layout_width="10dp"
    android:layout_height="10dp"
    android:layout_centerInParent="true"
    android:background="#FFAABB" />

</RelativeLayout>

however it does not work, even if i set margin on the fake view.

Any ideas?

//EDIT//

thanks for you answers guys, padding attribute works, however as it is a big image and if i want it to start at 2/5ths of screen height, it covers the center point of screen, so if i use padding attribute it works but it pushes it away from center and does not allow it to cover it. Sorry my bad

Though, i made it work using linear layout, which i wanted to avoid because there are more view on top and bottom next to each other so it would lead to nested views using linear layout. Unfortunately i think its the only option.

It basically it uses another linear layout that fills the remaining space left unused by top and bottom views with height=0dp and weight=1 and sets its gravity to center

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:padding="20dp">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:orientation="horizontal"
    android:gravity="center" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:contentDescription="@string/application_logo_description"
        android:src="@drawable/mylight" />

     <ImageButton
        android:id="@+id/settings_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="right"
        android:background="@null"
        android:contentDescription="@string/settings_button_description"
        android:src="@drawable/settings_button" /> 
</LinearLayout>

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:gravity="center"
    android:orientation="vertical" >

    <ImageButton
        android:id="@+id/flashlight_button"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@null"
        android:contentDescription="@string/flashlight_button_description"
        android:src="@drawable/flashlight_button_selector" />

    <View
        android:id="@+id/fakeView"
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:layout_marginTop="60dp"
        android:background="#FFAABB" />
</LinearLayout>

<ImageView
    android:id="@+id/imageView2"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|center_horizontal"
    android:contentDescription="@string/powered_by_description"
    android:src="@drawable/powered_by" />

<ImageButton
    android:id="@+id/ad_button"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_gravity="bottom|center_horizontal"
    android:background="@null"
    android:contentDescription="@string/ad_button_description"
    android:src="@drawable/freeml" />

 </LinearLayout>

Thanks for your input.

回答1:

depending on the screen size of the target device, padding by X dp might move it more than just a fifth of the height.

you might have to code this movement yourself.

but then again, nothing prevents you from doing

<RelativeLayout 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="@drawable/background"
 android:padding="20dp" >

<View
android:id="@+id/fakeView"
android:layout_width="10dp"
android:layout_height="10dp"
android:layout_centerInParent="true"
android:background="#FFAABB" />

<ImageButton
android:id="@+id/flashlight_button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_above="@+id/fakeView"
android:marginBottom="50dp"
android:background="@null"
android:contentDescription="@string/flashlight_button_description"
android:src="@drawable/freeml_bright" />

回答2:

Don't use margin, use padding (top), like so:

<View
android:id="@+id/fakeView"
android:layout_width="10dp"
android:layout_height="10dp"
android:layout_centerInParent="true"
android:paddingTop="80dp"
android:background="#FFAABB" />

That should work, though I've not tested it!

回答3:

try using attribute android:layout_toLeftOf="@+id/fakeView"