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I want to make folders of dimens according to screen size and not according to density so what will be the dp values for each screen size. I want to adjust my DP value according to screen size only and not according to density so is there any formula for calculating dp for different screen size . As there is a relation between density , pixel and dp . But i want it for different screen size . It is like for normal-xhdpi screen and for normal-xxhdpi screen the size of the button should be same as independent of density as name suggest of "DP"

ritwik
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    Possible duplicate of [What is the difference between "px", "dp", "dip" and "sp" on Android?](http://stackoverflow.com/questions/2025282/what-is-the-difference-between-px-dp-dip-and-sp-on-android) – harshithdwivedi Jan 19 '17 at 07:05
  • Use this library.https://github.com/Shekhar14o3/Library-On-Different-Screen-Supports – Aman Shekhar Jan 19 '17 at 07:06
  • For normal-xxhdpi my button is coming smaller as compare to normal--xhdpi . But i want that for every normal phone size it should be same so what dp relation should have to be use for different screen size like small,large,normal and xlarge – ritwik Jan 19 '17 at 07:21

2 Answers2

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Create three different Layouts Folder in your res folder for all devices and use the dimensions accordingly.

Generic Layout Folders

res/layout-small
res/layout-normal
res/layout-large
res/layout-xlarge

After you are done with making your Normal/Medium Layouts follow these steps:

  1. Convert the Normal Dimensions for other Screen Sizes.
  2. Copy your Normal Layout xml files in to other Folders.
  3. Change the suffix of the dimensions used according to the folder that you are in
  4. Resize the Image Resources in your drawable folder (Width and Height - Same technique as we used for converting the dimens) and put them in their respective drawable folder (drawable-ldpi, drawable-mdpi, drawable-hdpi, drawable-xdpi and so on).
  5. Then your Layouts should work on every device with correct positioning.

For converting Values 

0.75 - ldpi  (small)   //mdpi dimens *0.75
1.0  - mdpi  (normal)  //First create these dimensions
1.5  - hdpi  (large)   //mdpi dimens *1.5
2.0  - xhdpi (xLarge)  //mdpi dimens *2.0

For Example

android:layout_width="66dip" //in normal
android:layout_width="100dip"//in large 66*1.5=100(approx)
android:layout_width="52dip" //in small 66*0.75=52(approx)

Also new Qualifier has been introduced - SmallestWidth - AvailableScreenWidth - AvailableScreenHeight

read more about it here https://developer.android.com/guide/practices/screens_support.html

If you are looking in Java code

 /// convert dp to pixels
   public static int dp2px(Context context, float dp) {
      return Math.round(dp * context.getResources().getDisplayMetrics().density);
   }

I hope this helps.

Jayanth
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  • One solution which comes in my mind after reading your solution is that (Please correct me if i am wrong) :- when screen size is small the divide the px with 3. if screen size is small then divide px with 2 and for other screen size keep pixel and dp as it is , Independent of the density of the screen – ritwik Jan 19 '17 at 07:38
  • read full answer, i have given step by step procedure and examples too – Jayanth Jan 19 '17 at 07:43
  • For xhdpi , it shouldn't be like divide by 2 . Reason being as as it depends upon density and value of density for xhdpi is 2 so for mdpi lets take an example if value is 30 therefore converting into pixel , it would be 30 px as 1 dp = 1 px for mdpi and then dividing by 2 i.e. density so it will be out to 15dp for xhdpi , in ypu r case it will be 45 dp what will be right – ritwik Jan 19 '17 at 07:55
  • Yes it's not divide by 2 it's multiply by 2 :) – Jayanth Jan 19 '17 at 07:58
  • Is it necessary to make dimens as normal-xhdpi, normal-xxhdpi or is it okay to make only for normal dimens file thats it i want to make for different screen size. – ritwik Jan 19 '17 at 08:08
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public static float dpToPx(Resources rs,float dp){
        DisplayMetrics metrics = rs.getDisplayMetrics();
        float px = dp * (metrics.densityDpi/160f);
        return px;
    }

public static float pxToDp(Resources rs,float px){ 
        DisplayMetrics metrics = rs.getDisplayMetrics();
        float dp = px / (metrics.densityDpi / 160f);
        return dp;

    }
Junaid Hafeez
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  • This formulae takes density into consideration so like for norma-xxhdpi screen the size of screen would be smaller as compare to normal-xhdpi screen . I want it to be same for all normal screen phone. What will be the formula for converting px into dp relative to screen size only – ritwik Jan 19 '17 at 07:28