Develop Reference

Android loading images to ImageView from drawable using only the file name

I need to load an image from drawable to an image view.
The ImageView is part of a ListViewItem, hence I have a large number of items and a large number of images.
When loading, the app parses a JSON file which states, among other information, the file name to be loaded per list item.
for example, "test_a.jpg".
The file "test_a.jpg" is located in "drawable".
I want, on runtime, to load drawable/test_a.jpg, test_b.jpg, big_chief.jpg and so on...
int intCurrImageResourceID = this.context.getResources().getIdentifier(strPictureName, "drawable", context.getPackageName());
any ideas on how to achieve that?
*** EDIT ****
It turns out that you shouldn't use file extension. So image.jpg is wrong. image is right. Thanks all. Especially #Augusto Carmo.

---- updated (correct answer)
A question, in your code, is strPictureName equals, for example, to something like this: "myDogPicture.png"? If yes, you should remove ".png" from the string first. Test it :) To get images from drawable with resource ids, you should not use the image extension.
---- old answer
You can achieve this with the following code:
// example - your ImageView
ImageView myImageView = (ImageView)findViewById(R.id.my_image_view);
// suppose the name of your image in drawable/ is my_image_name.jpg.
myImageView.setImageResource(R.drawable.my_image_name);
If you already know what the mapping between strings and resource ids will be, what do you think about using enum? example:
public enum MyImage{
CAT_IMAGE("cat.png", R.drawable.cat),
DOG_IMAGE("dog.png", R.drawable.dog),
HORSE_IMAGE("horse.png", R.drawable.horse);
private final String fileName;
private final int resId;
MyImage(String fileName, int resId){
this.fileName = fileName;
this.resId = resId;
}
/**
*
* #param imageFileName
* #return -1 if image not found
*/
public int getResId(String imageFileName){
int resId = -1;
for (MyImage myImage : MyImage.values()) {
if (imageFileName.equals(myImage.fileName)){
resId = myImage.resId;
break;
}
}
return resId;
}
}

Drawable Reference

I have few images in my app ( they are all copied into res/drawable and have appropriate R.drawable reference) that I want to assign them to my ImageViews using contents of an string type variable. To illustrated, I have an image file named "c4.png" in my drawable folder and an string variable (card) that contains "c4". I want to see if there is any way I can use a code like this (ImageView1.setImageResource(R.drawable.card)) to assign image c4 to my ImageView1 instead of using ImageView1.setImageResource(R.drawable.c4). Basically, I am wondering if it is possible to replace a variable with the specific image name in the R.drawable.resourceName. I know that R.drawable.resourceName is an integer and I am not trying to change its type. I want to replace the resourceName with a variable. I appreciate any help

Use this to draw a random number in particular range-
int min = 0;
int max = 9;
Random r = new Random();
int i1 = r.nextInt(max - min + 1) + min;
Then using this number pick image from image array-
public Integer[] nImages = {
R.drawable.c1, R.drawable.c2,
R.drawable.c3, R.drawable.c4,
R.drawable.c5, R.drawable.c6,
R.drawable.c7, R.drawable.c8,
R.drawable.c9, R.drawable.c10
};
ImageView1.setBackgroundResource(nImages [i1]);
Hope this works.

Try this
Resources res = getResources();
int id = res.getIdentifier(card, "drawable", getPackageName());
img.setImageResource(id);
this may solve your problem.

Or you can put the images in the asset folder. Assets are referenced by their filename, as in
getAssets().open(<filename>);
This returns an InputStream. Afterwhich it is trivial to convert them to a Bitmap resource
BitmapFactory.decodeStream(inputStream);
And then use that bitmap for your ImageView. That should be straightforward with
imageView.setImageBitmap(bitmap);

I want to replace the resourceName with a variable.
Instead of declaring the variable card as a string declare it as an Integer. So that you can use it like the following.
int card=R.drawable.c4;
ImageView1.setImageResource(card);
You probably can not do something like R.drawable.card because the R file is generated according to the resources in the drawable folder.
hope this helps

Android getResources/getIdentifier not returning ID

I have code like tthis:
String s = "replace__menu__" + data.imageid + ".png";
int RID = this.getApplicationContext().getResources().getIdentifier(s, "drawable-hdpi", getPackageName());
The String s = instruction sets a value that is the same as one of names in my res/drawable-hdpi folder. However, the returned value sets RID to the value 0
Any idea why my code is not working? Am I doing something wrong?

Try this
String s = "replace__menu__" + data.imageid; // image name is needed without extention
int RID = this.getApplicationContext().getResources().getIdentifier(s, "drawable", getPackageName());

".png" is not part of a ressource name
"drawable-hdpi" I would try just 'drawable' instead

Reference to R.drawabe dynamically?

I got about 200+ Country names in my app.
I got 200+ flag icons for each country.
The flag icons names are equals the country names, so like:
Country name: ENG, icon name eng.png
I want to make a list of them in my app to select country.
I dont want to build the layout by manually and add 200+ icons for each and every TextView...
My question is, can i add dynamically somehow ?
Something like this:
private void setIcon(String iconName)
{
countryIcon.setBackgroundResource(R.drawable. /* and i need the magic here*/ +iconName )
}
So can i reference to R.drawable dynamically by somehow with param?

Try this:
private void setIcon(String iconName) {
Resources res = getResources();
int imageResource = res.getIdentifier("drawable/" + iconName, null, getPackageName());
Drawable image = res.getDrawable(imageResource);
countryIcon.setBackgroundResource(image);
}

If you've a pattern, is not difficult at all.
Here's an example. I did this for loading flag-images in a ListView depending the flag IDs of each row-object. Once i've the language_id i get the language_KEY (String) which is the same as my icon's name:
int ico_id, int visible=View.visible();
String flag;
Bitmap icona;
flag= (MyWharehouse.getLangKey(language_id.get(position))).toLowerCase(); //get the image.png name
ico_id = a.getResources().getIdentifier(flag, "drawable", a.getString(R.string.package_str));
icona = BitmapFactory.decodeResource(a.getResources(), ico_id);
((ImageView)a.findViewById(R.id.im_lang_01)).setImageBitmap(icona); //changing the image

Android, reference things in R.drawable. using variables?

say I want to dynamically load an image file in R.drawable.* based on the value of a string
Is there a way to do this? It seems like I need to statically refer to anything in R.

Have you declared the id for the image in XML file? If you did, you can use the following method:
Let's say you have picture.png in your res/drawable folder.
In your activity, you can set your image resource in the main.xml file
<ImageView android:id="#+id/imageId" android:src="#drawable/picture"></ImageView>
In FirstActivity
//to retrieve image using id set in xml.
String imageString = "imageId"
int resID = getResources().getIdentifier(imageString , "id", "package.name");
ImageView image = (ImageView) findViewById(resID);
imageString is the dynamic name. After which you can get the identifier of the dynamic resource.
Another method, you can do this:
//to retrieve image in res/drawable and set image in ImageView
String imageName = "picture"
int resID = getResources().getIdentifier(imageName, "drawable", "package.name");
ImageView image;
image.setImageResource(resID );
You will be able to reference your image resource and set your ImageView to it.

int drawableId = getResources().getIdentifier(drawablename, "drawable", getPackageName());
imageview.setImageResource(drawableId);
Try this. This should work.

Class res = R.string.class;
Field field = res.getField("x" + pos);
headerId = field.getInt(null);
header.setText(headerId);
this works with drawables as well, just edit the string. the header part is not required, it's just an example pulled from something I wrote a while ago.