判断资源存在与否如判断一个drawable的图片存在及通过id加载图片

int i=  getResources().getIdentifier("icon", "drawable", getPackageName()) ;
      if(i>0)
      {Log.i("aa","aa");}
      else
      {Log.i("vbv","aa");}

 

或者

 int resID = getResources().getIdentifier("org.loveandroid.androidtest:drawable/gallery_photo_1",null,null);

 

int resID = getResources ( ). getIdentifier ( "org.anddev.android.testproject:drawable/bug", null,  null ); 
// or 
int resID = getResources ( ). getIdentifier ( "bug",  "drawable", "org.anddev.android.testproject" );

第一个参数其实

full_package:type/filename_without_ending是这种格式 然后其他的可以为null

 int idFlag = getResources().getIdentifier(
       getPackageName() + ":drawable/flag",
       null, null);
 // 或是
 int idFlag = getResources().getIdentifier(
       "flag", "drawable", getPackageName());

 

 var Drawable[] dw = new Drawable[10];

 for (int i = 1; i <= 10; i++) {
   int id = getResources().getIdentifier(
                     "flag" + i,
                     "drawable", getPackageName());
   dw[i-1] = getResources().getDrawable(id);
 }

 用反射发 可以得到 所有的资源

 private void
   _DumpAllResourceIDs(Class<?> classType)
     throws IllegalArgumentException {
   Field[] fIDs = classType.getFields();

   try {
     for (int i = 0; i < fIDs.length; i++) {
       Field fld = fIDs[i];
       int nID = fld.getInt(null);
       Log.d("dbg",
         classType.getSimpleName() + " " +
         i + ": " +
         fld.getName() + "=" +
         nID);
     }
   } catch (Exception e) {
     throw new IllegalArgumentException();
   }
 }

 

 import java.lang.reflect.Field;
 ...
   _DumpAllResourceIDs(R.layout.class);
   _DumpAllResourceIDs(R.drawable.class);

 结果

 R$layout 0: main=2130903040
 R$layout 1: small_spinner_dropdown_item=2130903041
 R$drawable 0: icon=2130837504