android – How to get screen width and height-ThrowExceptions

Exception or error:

I tried to use following code to get screen width and height in android app development:

Display display = getWindowManager().getDefaultDisplay(); 
int screenWidth = display.getWidth();
int screenHeight = display.getHeight();

but I got NullPointerException for my display, why? how to get screen width and height then?

How to solve:

If you’re calling this outside of an Activity, you’ll need to pass the context in (or get it through some other call). Then use that to get your display metrics:

DisplayMetrics metrics = context.getResources().getDisplayMetrics();
int width = metrics.widthPixels;
int height = metrics.heightPixels;

UPDATE: With API level 17+, you can use getRealSize:

Point displaySize = new Point();
activity.getWindowManager().getDefaultDisplay().getRealSize(displaySize);

If you want the available window size, you can use getDecorView to calculate the available area by subtracting the decor view size from the real display size:

Point displaySize = new Point();
activity.getWindowManager().getDefaultDisplay().getRealSize(displaySize);

Rect windowSize = new Rect();
ctivity.getWindow().getDecorView().getWindowVisibleDisplayFrame(windowSize);

int width = displaySize.x - Math.abs(windowSize.width());
int height = displaySize.y - Math.abs(windowSize.height());
return new Point(width, height);

getRealMetrics may also work (requires API level 17+), but I haven’t tried it yet:

DisplayMetrics metrics = new DisplayMetrics();
activity.GetWindowManager().getDefaultDisplay().getRealMetrics(metrics);

###

Within an activity, you can call:

int width = this.getResources().getDisplayMetrics().widthPixels;
int height = this.getResources().getDisplayMetrics().heightPixels;

When you’re in a View, then you need to get the Context first:

int width = getApplicationContext().getResources().getDisplayMetrics().widthPixels;
int height = getApplicationContext().getResources().getDisplayMetrics().heightPixels;

This will work in all Android version, available since API 1, and never deprecated.

###

From service:

Display  display= ((WindowManager) getSystemService(Context.WINDOW_SERVICE)).getDefaultDisplay();
int width = display.getWidth(); 
int height = display.getHeight(); 

###

This is what finally worked for me:

DisplayMetrics metrics = this.getResources().getDisplayMetrics();
int width = metrics.widthPixels;
int height = metrics.heightPixels;

###

Try via context.getResources().getDisplayMetrics() if you have a context available.

###

DisplayMetrics metrics = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(metrics);

int height = metrics.heightPixels;
int width = metrics.widthPixels;

i guess the code which you wrote is deprecated.

###

if (Build.VERSION.SDK_INT >= 11) {
        Point size = new Point();
        try {
            this.getWindowManager().getDefaultDisplay().getRealSize(size);
            screenWidth = size.x;
            screenHeight = size.y;
        } catch (NoSuchMethodError e) {
             screenHeight = this.getWindowManager().getDefaultDisplay().getHeight();
             screenWidth=this.getWindowManager().getDefaultDisplay().getWidth();
        }

    } else {
        DisplayMetrics metrics = new DisplayMetrics();
        this.getWindowManager().getDefaultDisplay().getMetrics(metrics);
        screenWidth = metrics.widthPixels;
        screenHeight = metrics.heightPixels;
    }

###

Try with the following code to get width and height of screen

int widthOfscreen =0;
int heightOfScreen = 0;
DisplayMetrics dm = new DisplayMetrics();
        try {
            ((Activity) context).getWindowManager().getDefaultDisplay()
                    .getMetrics(dm);
        } catch (Exception ex) {
        }
         widthOfscreen  = dm.widthPixels;
heightOfScreen  = dm.heightPixels;

###

WindowManager w = getWindowManager();
Display d = w.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
d.getMetrics(metrics);

Log.d("WIDTH: ", String.valueOf(d.getWidth()));
Log.d("HEIGHT: ", String.valueOf(d.getHeight()));

###

       /*
        *DisplayMetrics: A structure describing general information about a display, such as its size, density, and font scaling.
        * */

 DisplayMetrics metrics = getResources().getDisplayMetrics();

       int DeviceTotalWidth = metrics.widthPixels;
       int DeviceTotalHeight = metrics.heightPixels;

###

    int scrWidth  = getWindowManager().getDefaultDisplay().getWidth();
    int scrHeight = getWindowManager().getDefaultDisplay().getHeight();

###

Display display = getActivity().getWindowManager().getDefaultDisplay(); 
int screenWidth = display.getWidth();
int screenHeight = display.getHeight();
Log.d("Tag", "Getting Width >> " + screenWidth);
Log.d("Tag", "Getting Height >> " + screenHeight);

This worked properly in my application

###

Alternative way using function

private int[] getScreenSIze(){
        DisplayMetrics displaymetrics = new DisplayMetrics();
        getWindowManager().getDefaultDisplay().getMetrics(displaymetrics);
        int h = displaymetrics.heightPixels;
        int w = displaymetrics.widthPixels;

        int[] size={w,h};
        return size;

    }

on button click or on your create function add the following code

int[] screenSize= getScreenSIze();
        int width=screenSize[0];
        int height=screenSize[1];
        screenSizes.setText("Phone Screen sizes \n\n  width = "+width+" \n Height = "+height);

See demo source code

###

below answer support api level below and above 10

 if (Build.VERSION.SDK_INT >= 11) {
            Point size = new Point();
            try {
                this.getWindowManager().getDefaultDisplay().getRealSize(size);
                screenWidth = size.x;
                screenHeight = size.y;
            } catch (NoSuchMethodError e) {
                 screenHeight = this.getWindowManager().getDefaultDisplay().getHeight();
                 screenWidth=this.getWindowManager().getDefaultDisplay().getWidth();
            }

        } else {
            DisplayMetrics metrics = new DisplayMetrics();
            this.getWindowManager().getDefaultDisplay().getMetrics(metrics);
            screenWidth = metrics.widthPixels;
            screenHeight = metrics.heightPixels;
        }

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