how to access the drawable resources by name in android

问题

In my application, I need to get the some bitmap drawables somewhere where I do not want to keep the reference R. So I create a class DrawableManager to manage the drawables.

public class DrawableManager {
    private static Context context = null;

    public static void init(Context c) {
        context = c;
    }

    public static Drawable getDrawable(String name) {
        return R.drawable.?
    }
}

Then I want to get the drawable by name somewhere like this( the car.png is put inside the res/drawables):

Drawable d= DrawableManager.getDrawable("car.png");

However as you can see, I can not access the resources by the name:

public static Drawable getDrawable(String name) {
    return R.drawable.?
}

Any alternatives?

回答1:

Note that your approach is almost always the wrong way to do things (better to pass the context into the object itself that is using the drawable than keeping a static Context somewhere).

Given that, if you want to do dynamic drawable loading, you can use getIdentifier:

Resources resources = context.getResources();
final int resourceId = resources.getIdentifier(name, "drawable", 
   context.getPackageName());
return resources.getDrawable(resourceId);

回答2:

You could do something like this.-

public static Drawable getDrawable(String name) {
    Context context = YourApplication.getContext();
    int resourceId = context.getResources().getIdentifier(name, "drawable", YourApplication.getContext().getPackageName());
    return context.getResources().getDrawable(resourceId);
}

In order to access the context from anywhere, you may extend Application class.-

public class YourApplication extends Application {

    private static YourApplication instance;

    public YourApplication() {
        instance = this;
    }

    public static Context getContext() {
        return instance;
    }
}

And map it in your Manifest application tag

<application
    android:name=".YourApplication"
    ....

回答3:

Modify image content:

    ImageView image = (ImageView)view.findViewById(R.id.imagenElement);
    int resourceImage = activity.getResources().getIdentifier(element.getImageName(), "drawable", activity.getPackageName());
    image.setImageResource(resourceImage);

来源：https://stackoverflow.com/questions/16369814/how-to-access-the-drawable-resources-by-name-in-android

标签

android

drawable