What is the size of ActionBar in pixels?

问题:

I need to know the exact size of ActionBar in pixels so to apply correct background image.

回答1:

To retrieve the height of the ActionBar in XML, just use

?android:attr/actionBarSize

or if you're an ActionBarSherlock or AppCompat user, use this

?attr/actionBarSize

If you need this value at runtime, use this

final TypedArray styledAttributes = getContext().getTheme().obtainStyledAttributes(
                    new int[] { android.R.attr.actionBarSize });
mActionBarSize = (int) styledAttributes.getDimension(0, 0);
styledAttributes.recycle();

If you need to understand where this is defined:

1. The attribute name itself is defined in the platform's /res/values/attrs.xml
2. The platform's themes.xml picks this attribute and assigns a value to it.
3. The value assigned in step 2 depends on different device sizes, which are defined in various dimens.xml files in the platform, ie. core/res/res/values-sw600dp/dimens.xml

回答2:

From the de-compiled sources of Android 3.2's framework-res.apk, res/values/styles.xml contains:

<style name="Theme.Holo">
    <!-- ... -->
    <item name="actionBarSize">56.0dip</item>
    <!-- ... -->
</style>

3.0 and 3.1 seem to be the same (at least from AOSP)...

回答3:

To get the actual height of the Actionbar, you have to resolve the attribute actionBarSize at runtime.

TypedValue tv = new TypedValue();
context.getTheme().resolveAttribute(android.R.attr.actionBarSize, tv, true);
int actionBarHeight = getResources().getDimensionPixelSize(tv.resourceId);

回答4:

One of the Honeycomb samples refers to ?android:attr/actionBarSize

回答5:

I needed to do replicate these heights properly in a pre-ICS compatibility app and dug into the framework core source. Both answers above are sort of correct.

It basically boils down to using qualifiers. The height is defined by the dimension "action_bar_default_height"

It is defined to 48dip for default. But for -land it is 40dip and for sw600dp it is 56dip.

回答6:

If you're using the compatibility ActionBar from the recent v7 appcompat support package, you can get the height using

@dimen/abc_action_bar_default_height

Documentation

回答7:

With the new v7 support library (21.0.0) the name in R.dimen has changed to @dimen/abc_action_bar_default_height_material.

When upgrading from a previous version of the support lib you should therefore use that value as the actionbar's height

回答8:

If you are using ActionBarSherlock, you can get the height with

@dimen/abs__action_bar_default_height

回答9:

@AZ13's answer is good, but as per the Android design guidelines, the ActionBar should be at least 48dp high.

回答10:

The Class Summary is usually a good place to start. I think the getHeight() method should suffice.

EDIT:

If you need the width, it should be the width of the screen (right?) and that can be gathered like this.

回答11:

On my Galaxy S4 having > 441dpi > 1080 x 1920 > Getting Actionbar height with getResources().getDimensionPixelSize I got 144 pixels.

Using formula px = dp x (dpi/160), I was using 441dpi, whereas my device lies
in the category 480dpi. so putting that confirms the result.

回答12:

I did in this way for myself, this helper method should come in handy for someone:

private static final int[] RES_IDS_ACTION_BAR_SIZE = {R.attr.actionBarSize};

/**
 * Calculates the Action Bar height in pixels.
 */
public static int calculateActionBarSize(Context context) {
    if (context == null) {
        return 0;
    }

    Resources.Theme curTheme = context.getTheme();
    if (curTheme == null) {
        return 0;
    }

    TypedArray att = curTheme.obtainStyledAttributes(RES_IDS_ACTION_BAR_SIZE);
    if (att == null) {
        return 0;
    }

    float size = att.getDimension(0, 0);
    att.recycle();
    return (int) size;
}

回答13:

public int getActionBarHeight() {
    int actionBarHeight = 0;
    TypedValue tv = new TypedValue();
    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB) {
        if (getTheme().resolveAttribute(android.R.attr.actionBarSize, tv,
                true))
            actionBarHeight = TypedValue.complexToDimensionPixelSize(
                    tv.data, getResources().getDisplayMetrics());
    } else {
        actionBarHeight = TypedValue.complexToDimensionPixelSize(tv.data,
                getResources().getDisplayMetrics());
    }
    return actionBarHeight;
}