Android how do I set a percentage padding/margin so EditText has 10% margin on either side?

Does android support % or is there a way to approximate. I have two very different screen sizes and I but percentage-wise I want the EditBox in 开发者_StackOverflow中文版the activity to have same margin for both screen size as a proportion of screen size. How can this be done.

It doesn't really support setting values by percent(except for some of the xml Animation files seem to) If you are dead set on using a percentage the best way I can think of is from java call getWidth and getHeight then multiply those by your decimal and set the result with setMargin(), or setPadding().

This is possible in XML by wrapping your EditText inside of a LinearLayout:

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:weightSum="10"
    android:gravity="center"
    >       

    <EditText
        android:layout_height="wrap_content"
        android:layout_width="0dip"
        android:layout_weight="8"
        />

</LinearLayout>

Edit: The Layouts from this answer are now deprecated. Use the solution that Eugene Brusov proposed. Also, thank you chancyWu for the comment.

There is now a better way that came out with support library version 23.0.0 (about time, right?). You can now use PercentFrameLayout or PercentRelativeLayout.

If you wanted the EditText to be 80% of the screen's width with a 10% margin on either side, the code would look like this:

<android.support.percent.PercentRelativeLayout
         xmlns:android="http://schemas.android.com/apk/res/android"
         xmlns:app="http://schemas.android.com/apk/res-auto"
         android:layout_width="match_parent"
         android:layout_height="match_parent">

     <EditText
         android:layout_height="wrap_content"
         app:layout_widthPercent="80%"
         app:layout_marginStartPercent="10%"
         app:layout_marginEndPercent="10%"/>

</android.support.percent.PercentRelativeLayout>

You can also take a look at PercentLayoutHelper.PercentLayoutParams

It's possible with Guideline introduced in ConstraintLayout.

For example you can place your EditText top at 25% of screen height and left and right at 20% of screen width:

Here's the layout source:

<androidx.constraintlayout.widget.ConstraintLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <EditText
        android:id="@+id/editText"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPersonName"
        android:text="Name"
        app:layout_constraintLeft_toLeftOf="@+id/left_guideline"
        app:layout_constraintRight_toLeftOf="@+id/right_guideline"
        app:layout_constraintTop_toTopOf="@+id/top_guideline" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/top_guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="horizontal"
        app:layout_constraintGuide_percent="0.25" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/left_guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.2" />

    <androidx.constraintlayout.widget.Guideline
        android:id="@+id/right_guideline"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        app:layout_constraintGuide_percent="0.8" />

</androidx.constraintlayout.widget.ConstraintLayout>

What I did in this situation was put the view inside a horizontal LinearLayout, add an empty view (before or after your main view or layout depending on whether you want the margin to be on the left or on the right) turn both views' width to 0dp and then give the empty view a value of "1" in weight while I gave the View/Layout that needed margin a value of "4" in weight.

This resulted in a 1/5 (20%) left margin.

You can apply this to Top and Bottom margin/padding as well.

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

    <View
        android:layout_width="0dp"
        android:layout_height="match_parent"
        android:layout_weight="1" />

    <LinearLayout
    android:layout_width="0dp"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:layout_weight="4"
    >
    
    <!--Your content goes here -->

    </LinearLayout>

</LinearLayout>