Develop Reference

(Android)Unable to get the correct screen width for some devices

Display display = ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
screen_width = display.getWidth();
screen_height = display.getHeight();
I understand that the code above could drive me to get the screen width and height. I put this code in "onCreate" of "MainActivity".
But my friend's mobile device could not show the desired layout. Yet, it is too trouble for me to debug in his mobile device. Thus, I look forward to the help here.
My Question is ...
Is it right to get the width and height in "onCreate"?
Is it useful to get the width and height of all devices? (of course, API>=11)

Yes it's right to get the Screen Height and width in onCreate() method because if your Screen rotates then your onCreate will be called. and it's not mandatory that you should take Screen Height & width if needed OK or else you can manage it in Xml as well. To get Screen height and width i think this is the best way...
DisplayMetrics displaymetrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
int height = displaymetrics.heightPixels;
int width = displaymetrics.widthPixels;
for more details you use this link as well
http://developer.android.com/reference/android/view/Display.html

You could try metrics instead:
DisplayMetrics metrics = Resources.getSystem().getDisplayMetrics();
int displayHeight = metrics.heightPixels;
int displayWidth = metrics.widthPixels;
Doing it in onCreate should be fine.
But honestly, I don't think you are really getting the wrong height and width. The screen size is probably just very different from your test devices.
You will need to debug with his phone at least once to find out what the problem is.
In my opinion it is a good approach to get the width and height, because it gives you more control. Most layout stuff could be done by working with proper layouts (eg LinearLayouts with weight), but there are cases where doing it manually will work better. You can do things more precisely, but it will be more work.
Also if you don't have a large variety of devices for testing it will be tough to adjust it properly. Just think about all the different sizes the Android world can confront you with. I for example had some problems with very small devices, like a Galaxy Mini. Also very big devices like tablets might be a problem. Theres just no way around testing edgecases if you want to do it manually.

Separate 1024 width devices

I am developing an Android app that is causing me problems with devices that have 1024 as their width dimension. I have tried creating a layout folder layout-w1024 and layout-mdpi-sw1024dp; but the device uses the layout-mdpi folder instead. I am using 15 as the minimum android version.
Is there any other way using which I can separate 1024 devices?

You can do it programmatically if it's suitable for your project, something like this would call a different layout depending on the dimensions of the screen. This has some limitations though since it can only be called from an Activity (shouldn't be a problem in your case) and if you have problems with layouts all over your application it may not be very scalable.
The conditional width == 1024 should probably be replaced with something greater than or more specific, you'll need to play with this for a while to make it work. You should also account for the height of the screen, not only the width.
Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
Or if you want it in pixels instead:
DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);
int width = metrics.widthPixels;
And then:
//Depending on the width, set one layout or anotherone
setContentView(width == 1024?R.layout.for1024:R.layout.normal);
Source

auto resizing textView with different density devices android

At the top of my app, I have a title which should be shown in the middle, and a button on the right. As the textViews length is behind my control, I sometimes have my title crossing the button due to long length of the content of it.
After following this, I somehow tend to solve the problem. My device was HTC desire. Unfortunately, if I check with Galaxy SIII, it doesn't do the trick.
I am wondering how I can manage this in terms of different devices with different densities.
My controls inside the relative layout

You can also check the device screen density by this--
WindowManager wm = (WindowManager) _context.getSystemService(Context.WINDOW_SERVICE);
Display display = wm.getDefaultDisplay();
int screenWidth = display.getWidth();
int screenHeight = display.getHeight();
And can manage accordingly whats your apps needed..

just use weightsum in your xml and make width of all the views as fill parent ..... this makes auto resizing of your textview

you can maintain layouts according to their DPI`s
replicate the same XML data in XHDPI (As S3 falls in XHDPI) and test it similarly replicate the XML data in HDPI
but
keep in mind the following Thing Pixel Ratio of the layOut as
following
in LDPI its 1:0.75
in MDPI its 1:1
in HDPI its 1:1.5
in XHDPI its 1:2

Display display = ((WindowManager) ctx.getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
DisplayMetrics dm = new DisplayMetrics();
display.getMetrics(dm);
float density = dm.density;
int screenWidth = display.getWidth();
With this code above, you'll have your screen density as float.. So you can use it to calculate your textView's width like:
int newWidth = (int) (density * 100);
which 100 is here based size.
Or you can have a ratio according to your screenWdith.
int newWidth = screenWidth / 2;

Android: AbsoluteLayout?

I am new to Android. I like having the free range of drawing objects where ever I want. So i have been using Absolute Layout. I get a message saying to use a different layout. And I have read that this is because of the different res of different phones. My question is, is this the only reason in not using Absolute Layout? I have made a method that uses metrics to adjust the pixels.
public int widthRatio(double ratioIn){
DisplayMetrics dm = new DisplayMetrics(); //gets screen properties
getWindowManager().getDefaultDisplay().getMetrics(dm);
double screenWidth = dm.widthPixels; //gets screen height
double ratio = screenWidth/100; //gets the ratio in terms of %
int displayWidth = (int)(ratio*ratioIn); //multiplies ratio desired % of screen
return displayWidth;
}
//method to get height or Ypos that is a one size fits all
public int heightRatio(double ratioIn){
DisplayMetrics dm = new DisplayMetrics(); //gets screen properties
getWindowManager().getDefaultDisplay().getMetrics(dm);
double screenHeight = dm.heightPixels; //gets screen height
double ratio = screenHeight/100; //gets the ratio in terms of %
int newHeight = (int)(ratio*ratioIn); //multiplies ratio by desired % of screen
return newHeight;
}
//sets size of any view (button, text, ...) to a one size fits all screens
public void setSizeByRatio(View object, int width, int height){
LayoutParams params = object.getLayoutParams();
params.width = widthRatio(width);
params.height = heightRatio(height);
}
So if i say setSizeByRatio(Button, 10, 25); It will set the buttons width to 10% of the width of the screen and the height to 25% percent of the screen.
Are there any phones that Absolute Layouts do not work on? Does this layout cause any other issues?

The reason why the AbsoluteLayout is deprecated is because you have alternatives in the LinearLayout or the GridLayout that does the same and more. It seems that you are trying to calculate positions based on absolute positions and number of pixels, an approach that should in general be avoided due to issues with varoius screen sizes and densities.
Read the link that #amiekuser provided and focus on the understanding how the best practice is. Some hints are creating images for ldpi, mdpi and hdpi folders, using the unit for dpi (density independent pixels) instead of raw pixels and how to test your app on multiple screen sizes and densities using the emulator.
Edit:
To set the x- and y-position of a View you must use LayoutParams. See this question on how to to set the TopMargin and LeftMargin for a View using LayoutParams.

Android phones comes in many form factors i.e. not only it varies greatly in terms of screen size(2.7", 3.2", 3.7" ....) but also in terms of resolution (480X800, 480X848 etc).
Google itself suggest not to use AbsoluteLayout. in fact its deprecated in the newer api versions.
The link below explains all these in details:
http://developer.android.com/guide/practices/screens_support.html
Check the best practices section.

Android WindowManager shows same screen size for different devices

I am debugging my application on 2 different Droid devices: Bionic and Droid3. When I use WindowManager to display device width & height, it shows 540x960 (portrait) and 960x540 (landscape) for both devices! How is that possible? The 2 devices are clearly of a different size. Here is the code:
Display display = getWindowManager().getDefaultDisplay();
final int width = display.getWidth();
final int height = display.getHeight();
Thanks,
Igor

I read that getWidth()/getHeight() is deprecated.
Try to use this:
Display display = getWindowManager().getDefaultDisplay();
Point displayDimensionInPixel = new Point();
display.getSize(displayDimensionInPixel);
I'm not shure right now because the Documentation isn't there anymore, but I think I can remember that getWidth()/getHeight() of Display dont return pixel dimensions.