android gets an instance of applicationId that uniquely identifies APP

Using getIdentifier () method, we can easily get the specified resource ID under each application package.

Mode 1

int indentify = getResources().getIdentifier( " com.test.demo:drawable/icon " ,null,null);

The first parameter format is: package name +: + resource folder name +/+ resource name; Is this format and then others can be null

Mode 2

intindentify= getResources().getIdentifier( " icon " ,  " drawable " ,  " com.test.demo " );

The first parameter is the ID name, the second is the resource attribute is ID or Drawable, and the third is the package name.

Sample code:

import java.lang.reflect.Field;
import android.content.Context;
public class ResourceUtil {
  private static Context sContext;
  public static void init(Context context) {
    if (context != null)
      sContext = context;
  }
  public static int getLayoutId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "layout", sContext.getPackageName());
  }
  public static int getStringId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "string",
        sContext.getPackageName());
  }
  public static int getDrawableId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "drawable", sContext.getPackageName());
  }
  public static int getStyleId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "style",
        sContext.getPackageName());
  }
  public static int getId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "id",
        sContext.getPackageName());
  }
  public static int getColorId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "color", sContext.getPackageName());
  }
  public static int getDimenId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "dimen",
        sContext.getPackageName());
  }
  public static int getAnimId(String paramString) {
    if (sContext == null)
      return 0;
    return sContext.getResources().getIdentifier(paramString, "anim", sContext.getPackageName());
  }
  //  Realized by reflection 
  public static final int[] getStyleableIntArray(String name) {
    try {
      if (sContext == null)
        return null;
      Field field = Class.forName(sContext.getPackageName() + ".R$styleable").getDeclaredField(name);
      int[] ret = (int[]) field.get(null);
      return ret;
    } catch (Throwable t) {
    }
    return null;
  }
  public static final int getStyleableIntArrayIndex(String name) {
    try {
      if (sContext == null)
        return 0;
      // use reflection to access the resource class
      Field field = Class.forName(sContext.getPackageName() + ".R$styleable").getDeclaredField(name);
      int ret = (Integer) field.get(null);
      return ret;
    } catch (Throwable t) {
    }
    return 0;
  }
}