Load dimension value from res/values/dimension.xml from source code

问题

I\'d like to load the value as it is. I have two dimension.xml files, one in /res/values/dimension.xml and the other one in /res/values-sw360dp/dimension.xml.

From source code I\'d like to do something like

getResources().getDimension(R.dimen.tutorial_cross_marginTop);

This works but the value I get is multiplied times the screen density factor (1.5 for hdpi, 2.0 for xhdpi, etc).

I also tried to do

getResources().getString(R.dimen.tutorial_cross_marginTop);

This would work in principle but I get a string that ends in \"dip\"...

回答1:

In my dimens.xml I have

<dimen name="test">48dp</dimen>

In code If I do

int valueInPixels = (int) getResources().getDimension(R.dimen.test)

this will return 72 which as docs state is multiplied by density of current phone (48dp x 1.5 in my case)

exactly as docs state :

Retrieve a dimensional for a particular resource ID. Unit conversions are based on the current DisplayMetrics associated with the resources.

so if you want exact dp value just as in xml just divide it with DisplayMetrics density

int dp = (int) (getResources().getDimension(R.dimen.test) / getResources().getDisplayMetrics().density)

dp will be 48 now

回答2:

Context.getResources().getDimension(int id);

回答3:

The Resource class also has a method getDimensionPixelSize() which I think will fit your needs.

回答4:

For those who just need to save some int value in the resources, you can do the following.

integers.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <integer name="default_value">100</integer>
</resources> 

Code

int defaultValue = getResources().getInteger(R.integer.default_value);

回答5:

You can use getDimensionPixelOffset() instead of getDimension, so you didn't have to cast to int.

int valueInPixels = getResources().getDimensionPixelOffset(R.dimen.test)

回答6:

You can write integer in xml file also..
have you seen [this] http://developer.android.com/guide/topics/resources/more-resources.html#Integer ? use as .

 context.getResources().getInteger(R.integer.height_pop);

回答7:

    This works but the value I get is multiplied times the screen density factor
  (1.5 for hdpi, 2.0 for xhdpi, etc).

I think it is good to get the value as per resolution but if you not want to do this give this in px.......

Density-independent pixel (dp)

A virtual pixel unit that you should use when defining UI layout, to express layout dimensions or position in a density-independent way. The density-independent pixel is equivalent to one physical pixel on a 160 dpi screen, which is the baseline density assumed by the system for a "medium" density screen. At runtime, the system transparently handles any scaling of the dp units, as necessary, based on the actual density of the screen in use. The conversion of dp units to screen pixels is simple: px = dp * (dpi / 160). For example, on a 240 dpi screen, 1 dp equals 1.5 physical pixels. You should always use dp units when defining your application's UI, to ensure proper display of your UI on screens with different densities.

I think it is good to change the value as per resolution but if you not want to do this give this in px.......

refer this link

as per this

dp

Density-independent Pixels - An abstract unit that is based on the physical density of the screen. These units are relative to a 160 dpi (dots per inch) screen, on which 1dp is roughly equal to 1px. When running on a higher density screen, the number of pixels used to draw 1dp is scaled up by a factor appropriate for the screen's dpi. Likewise, when on a lower density screen, the number of pixels used for 1dp is scaled down. The ratio of dp-to-pixel will change with the screen density, but not necessarily in direct proportion. Using dp units (instead of px units) is a simple solution to making the view dimensions in your layout resize properly for different screen densities. In other words, it provides consistency for the real-world sizes of your UI elements across different devices.

px

Pixels - Corresponds to actual pixels on the screen. This unit of measure is not recommended because the actual representation can vary across devices; each devices may have a different number of pixels per inch and may have more or fewer total pixels available on the screen.

来源：https://stackoverflow.com/questions/11121028/load-dimension-value-from-res-values-dimension-xml-from-source-code