How do I get the height and width of the Android N

2019-01-03 01:13发布

The black navigation bar on the bottom of the screen is not easily removable in Android. It has been part of Android since 3.0 as a replacement for hardware buttons. Here is a picture:

System Bar

How can I get the size of the width and the height of this UI element in pixels?

15条回答
ら.Afraid
2楼-- · 2019-01-03 01:53

The solution proposed by Egidijus and works perfectly for Build.VERSION.SDK_INT >= 17

But I got "NoSuchMethodException" during execution of the following statement with Build.VERSION.SDK_INT < 17 on my device:

Display.class.getMethod("getRawHeight").invoke(display);

I have modified the method getRealScreenSize() for such cases:

else if(Build.VERSION.SDK_INT >= 14) 
{
    View decorView = getActivity().getWindow().getDecorView();
    size.x = decorView.getWidth();
    size.y = decorView.getHeight();
}
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欢心
3楼-- · 2019-01-03 01:55

The NavigationBar height varies for some devices, but as well for some orientations. First you have to check if the device has a navbar, then if the device is a tablet or a not-tablet (phone) and finally you have to look at the orientation of the device in order to get the correct height.

public int getNavBarHeight(Context c) {
         int result = 0;
         boolean hasMenuKey = ViewConfiguration.get(c).hasPermanentMenuKey();
         boolean hasBackKey = KeyCharacterMap.deviceHasKey(KeyEvent.KEYCODE_BACK);

         if(!hasMenuKey && !hasBackKey) {
             //The device has a navigation bar
             Resources resources = c.getResources();

             int orientation = resources.getConfiguration().orientation;
             int resourceId;
             if (isTablet(c)){
                 resourceId = resources.getIdentifier(orientation == Configuration.ORIENTATION_PORTRAIT ? "navigation_bar_height" : "navigation_bar_height_landscape", "dimen", "android");
             }  else {
                 resourceId = resources.getIdentifier(orientation == Configuration.ORIENTATION_PORTRAIT ? "navigation_bar_height" : "navigation_bar_width", "dimen", "android");     
             }

             if (resourceId > 0) {
                 return resources.getDimensionPixelSize(resourceId);
             }
         }
         return result;
} 


private boolean isTablet(Context c) {
    return (c.getResources().getConfiguration().screenLayout
            & Configuration.SCREENLAYOUT_SIZE_MASK)
            >= Configuration.SCREENLAYOUT_SIZE_LARGE;
}
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Rolldiameter
4楼-- · 2019-01-03 01:59

Combining the answer from @egis and others - this works well on a variety of devices, tested on Pixel EMU, Samsung S6, Sony Z3, Nexus 4. This code uses the display dimensions to test for availability of nav bar and then uses the actual system nav bar size if present.

/**
 * Calculates the system navigation bar size.
 */

public final class NavigationBarSize {

	private final int systemNavBarHeight;
	@NonNull
	private final Point navBarSize;

	public NavigationBarSize(@NonNull Context context) {
		Resources resources = context.getResources();
		int displayOrientation = resources.getConfiguration().orientation;
		final String name;
		switch (displayOrientation) {
			case Configuration.ORIENTATION_PORTRAIT:
				name = "navigation_bar_height";
				break;
			default:
				name = "navigation_bar_height_landscape";
		}
		int id = resources.getIdentifier(name, "dimen", "android");
		systemNavBarHeight = id > 0 ? resources.getDimensionPixelSize(id) : 0;
		navBarSize = getNavigationBarSize(context);
	}

	public void adjustBottomPadding(@NonNull View view, @DimenRes int defaultHeight) {
		int height = 0;
		if (navBarSize.y > 0) {
			// the device has a nav bar, get the correct size from the system
			height = systemNavBarHeight;
		}
		if (height == 0) {
			// fallback to default
			height = view.getContext().getResources().getDimensionPixelSize(defaultHeight);
		}
		view.setPadding(0, 0, 0, height);
	}

	@NonNull
	private static Point getNavigationBarSize(@NonNull Context context) {
		Point appUsableSize = new Point();
		Point realScreenSize = new Point();
		WindowManager windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
		if (windowManager != null) {
			Display display = windowManager.getDefaultDisplay();
			display.getSize(appUsableSize);
			display.getRealSize(realScreenSize);
		}
		return new Point(realScreenSize.x - appUsableSize.x, realScreenSize.y - appUsableSize.y);
	}

}

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做个烂人
5楼-- · 2019-01-03 02:03

I hope this helps you

public int getStatusBarHeight() {
    int result = 0;
    int resourceId = getResources().getIdentifier("status_bar_height", "dimen", "android");
    if (resourceId > 0) {
        result = getResources().getDimensionPixelSize(resourceId);
    }
    return result;
}

public int getNavigationBarHeight()
{
    boolean hasMenuKey = ViewConfiguration.get(context).hasPermanentMenuKey();
    int resourceId = getResources().getIdentifier("navigation_bar_height", "dimen", "android");
    if (resourceId > 0 && !hasMenuKey)
    {
        return getResources().getDimensionPixelSize(resourceId);
    }
    return 0;
}
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We Are One
6楼-- · 2019-01-03 02:04

I resolved this issue for all devices(including Nexus 5, Samsung Galaxy Nexus 6 edge+, Samsung S10, Samsung Note II etc.). I think this will help you to handle device dependant issues.

Here I am adding two types of codes,

Java Code(for Native Android):

import android.content.Context;
import android.content.res.Resources;
import android.os.Build;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.ViewConfiguration;
import android.view.WindowManager;

public class DeviceSpec {

    private int resourceID = -1;
    private Display display = null;
    private DisplayMetrics displayMetrics = null;
    private DisplayMetrics realDisplayMetrics = null;
    private Resources resources = null;
    private WindowManager windowManager = null;

    public double GetNavigationBarHeight(Context context) {
        try {
            windowManager = (WindowManager) context.getSystemService(Context.WINDOW_SERVICE);
            display = windowManager.getDefaultDisplay();
            displayMetrics = new DisplayMetrics();
            if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.ICE_CREAM_SANDWICH_MR1) {
                realDisplayMetrics = new DisplayMetrics();
                display.getMetrics(displayMetrics);
                display.getRealMetrics(realDisplayMetrics);
                if(displayMetrics.heightPixels != realDisplayMetrics.heightPixels) {
                    resources = context.getResources();
                    return GetNavigationBarSize(context);
                }
            }
            else {
                resources = context.getResources();
                resourceID = resources.getIdentifier("config_showNavigationBar", "bool", "android");
                if (resourceID > 0 && resources.getBoolean(resourceID))
                    return GetNavigationBarSize(context);
            }
        }
        catch (Exception e){
            e.printStackTrace();
        }
        return 0;
    }

    private double GetNavigationBarSize(Context context) {
        resourceID = resources.getIdentifier("navigation_bar_height", "dimen", "android");
        if (resourceID > 0 && ViewConfiguration.get(context).hasPermanentMenuKey())
           return (resources.getDimensionPixelSize(resourceID) / displayMetrics.density);
        return 0;
    }
}

And C# code(for Xamarin Forms/Android)

int resourceId = -1;
        IWindowManager windowManager = null;
        Display defaultDisplay = null;
        DisplayMetrics displayMatrics = null;
        DisplayMetrics realMatrics = null;
        Resources resources = null;

        public double NavigationBarHeight
        {
            get
            {
                try
                {
                    windowManager = Forms.Context.GetSystemService(Context.WindowService).JavaCast<IWindowManager>();
                    defaultDisplay = windowManager.DefaultDisplay;
                    displayMatrics = new DisplayMetrics();
                    if (Build.VERSION.SdkInt >= BuildVersionCodes.JellyBeanMr2)
                    {
                        realMatrics = new DisplayMetrics();
                        defaultDisplay.GetMetrics(displayMatrics);
                        defaultDisplay.GetRealMetrics(realMatrics);
                        if (displayMatrics.HeightPixels != realMatrics.HeightPixels)
                        {
                            resources = Forms.Context.Resources;
                            return GetHeightOfNivigationBar();
                        }
                    }
                    else {
                        resources = Forms.Context.Resources;
                        resourceId = resources.GetIdentifier("config_showNavigationBar", "bool", "android");
                        if (resourceId > 0 && resources.GetBoolean(resourceId))
                            return GetHeightOfNivigationBar();
                    }
                }
                catch (Exception e) { }
                return 0;
            }
        }

        private double GetHeightOfNivigationBar()
        {
            resourceId = resources.GetIdentifier("navigation_bar_height", "dimen", "android");
            if (!ViewConfiguration.Get(Forms.Context).HasPermanentMenuKey && resourceId > 0)
            {
                return resources.GetDimensionPixelSize(resourceId) / displayMatrics.Density;
            }
            return 0;
        }
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【Aperson】
7楼-- · 2019-01-03 02:06

This is my code to add paddingRight and paddingBottom to a View to dodge the Navigation Bar. I combined some of the answers here and made a special clause for landscape orientation together with isInMultiWindowMode. The key is to read navigation_bar_height, but also check config_showNavigationBar to make sure we should actually use the height.

None of the previous solutions worked for me. As of Android 7.0 you have to take Multi Window Mode into consideration. This breaks the implementations comparing display.realSize with display.size since realSize gives you the dimensions of the whole screen (both split windows) and size only gives you the dimensions of your App window. Setting padding to this difference will leave your whole view being padding.

/** Adds padding to a view to dodge the navigation bar.

    Unfortunately something like this needs to be done since there
    are no attr or dimens value available to get the navigation bar
    height (as of December 2016). */
public static void addNavigationBarPadding(Activity context, View v) {
    Resources resources = context.getResources();
    if (hasNavigationBar(resources)) {
        int orientation = resources.getConfiguration().orientation;
        int size = getNavigationBarSize(resources);
        switch (orientation) {
        case Configuration.ORIENTATION_LANDSCAPE:
            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N &&
                context.isInMultiWindowMode()) { break; }
            v.setPadding(v.getPaddingLeft(), v.getPaddingTop(),
                         v.getPaddingRight() + size, v.getPaddingBottom());
            break;
        case Configuration.ORIENTATION_PORTRAIT:
            v.setPadding(v.getPaddingLeft(), v.getPaddingTop(),
                         v.getPaddingRight(), v.getPaddingBottom() + size);
            break;
        }
    }
}

private static int getNavigationBarSize(Resources resources) {
    int resourceId = resources.getIdentifier("navigation_bar_height",
                                             "dimen", "android");
    return resourceId > 0 ? resources.getDimensionPixelSize(resourceId) : 0;
}

private static boolean hasNavigationBar(Resources resources) {
    int hasNavBarId = resources.getIdentifier("config_showNavigationBar",
                                              "bool", "android");
    return hasNavBarId > 0 && resources.getBoolean(hasNavBarId);
}
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