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I have a button which are set size (in dp) in XML file as follows:

<?xml version="1.0" encoding="utf-8"?>
<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"
    tools:context=".MainActivity"
    >

    <FrameLayout 
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_marginLeft="0dp"
        android:layout_marginRight="0dp"
        android:layout_marginTop="80dp"
        android:layout_marginBottom="80dp"
        android:layout_centerInParent="true"
        >

        <Button
            android:id="@+id/btn1"
            android:layout_width="10dp"
            android:layout_height="10dp"
            android:scaleType="fitCenter"/>

        <Button
            android:id="@+id/btn2"
            android:layout_width="50dp"
            android:layout_height="50dp"
            android:scaleType="fitCenter"/>
    </FrameLayout>
</RelativeLayout>

I followed the answer in getWidth() and getHeight() of View returns 0 to get size of button. However, it return a wrong value 300,300 instead of 10dp and 50dp. What is happen in my code? Thank all

Button btn=(Button) findViewById(R.id.btn1);
btn.measure(FrameLayout.LayoutParams.WRAP_CONTENT, FrameLayout.LayoutParams.WRAP_CONTENT);
width_btn = btn.getMeasuredWidth();
height_btn = btn.getMeasuredHeight();
Log.d("TAG", String.valueOf(index)+String.valueOf(width_btn)+","+String.valueOf(height_btn));
Community
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Jame
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    You should be using `getWidth()` and `getHeight()`, not the `getMeasured*()` methods. You also shouldn't be calling `measure()` on the `Button`. – Mike M. Sep 18 '16 at 03:51
  • Could you provide the solution for that. I tried to call `getWidth()` and `getHeight()` methods in `onWindowFocusChanged` but the app does not goes to `onWindowFocusChanged` – Jame Sep 18 '16 at 03:54
  • Yeah, I don't like that method, since it's not really reliable, as far as I've found. I always use the method described in __2. Add a runnable to the layout queue: View.post()__ in [this answer there](http://stackoverflow.com/a/24035591). Find your `Button`, `post()` a `Runnable` to it, and get the width/height in that. I can post an example, if you can't get it to work for ya, but please give it a try first. My answer would really be pretty much just like the example there. – Mike M. Sep 18 '16 at 04:01

2 Answers2

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From layout file, it is clear that button height and width fixed. You can define button width and height in dimens.xml file as follows:

<dimen name="btn_width">50dp</dimen>
 <dimen name="btn_hieght">10dp</dimen>

Now set these height and width to layout

android:layout_width="@dimen/btn_width"
android:layout_height="@dimen/btn_hieght"

Now you can get width and height 

float hieght = getResources().getDimension(R.dimen.btn_hieght);
 float width  = getResources().getDimension(R.dimen.btn_width);

As Mike suggest, remove btn.measure line.

USKMobility
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0

add code to onPause the value will not be 0. because when you use getWidth getMeasureWidth。the view not to be mesure,layout,draw.

WangDaFu
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