Android – Convert DIP to PX

androiddensity-independent-pixel

I had written method to get the pixels from dip but it is not working. It give me runtime error.

Actually I was running this method in separate class and initialized in my Activity class

Board board = new Board(this);
board.execute(URL);

This code runs asynchronously. Please help me.

public float getpixels(int dp){
    //Resources r = boardContext.getResources();
    //float px = (int)TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dpis, r.getDisplayMetrics());
        
    final float scale = this.boardContext.getResources().getDisplayMetrics().density;
    int px = (int) (dp * scale + 0.5f);

    return px;
}

Best Answer

Try this:

Java

public static float dipToPixels(Context context, float dipValue) {
    DisplayMetrics metrics = context.getResources().getDisplayMetrics();
    return TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dipValue, metrics);
}

Kotlin

fun Context.dipToPixels(dipValue: Float) =
    TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dipValue, resources.displayMetrics)

Related Solutions

Formula for Converting px to dp and dp to px in Android

Note: The widely used solution above is based on displayMetrics.density. However, the docs explain that this value is a rounded value, used with the screen 'buckets'. Eg. on my Nexus 10 it returns 2, where the real value would be 298dpi (real) / 160dpi (default) = 1.8625.

Depending on your requirements, you might need the exact transformation, which can be achieved like this:

[Edit] This is not meant to be mixed with Android's internal dp unit, as this is of course still based on the screen buckets. Use this where you want a unit that should render the same real size on different devices.

Convert dp to pixel:

public int dpToPx(int dp) {
    DisplayMetrics displayMetrics = getContext().getResources().getDisplayMetrics();
    return Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));     
}

Convert pixel to dp:

public int pxToDp(int px) {
    DisplayMetrics displayMetrics = getContext().getResources().getDisplayMetrics();
    return Math.round(px / (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
}

Note that there are xdpi and ydpi properties, you might want to distinguish, but I can't imagine a sane display where these values differ greatly.

Android DP to PX Conversion – Convert DP, PX, SP

DP to PX:

public static int dpToPx(float dp, Context context) {
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, context.getResources().getDisplayMetrics());
}

SP to PX:

public static int spToPx(float sp, Context context) {
    return (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_SP, sp, context.getResources().getDisplayMetrics());
}

DP to SP:

public static int dpToSp(float dp, Context context) {
    return (int) (dpToPx(dp, context) / context.getResources().getDisplayMetrics().scaledDensity);
}

Best Answer

Related Solutions

Formula for Converting px to dp and dp to px in Android

Android DP to PX Conversion – Convert DP, PX, SP

Related Question