How to set image from PNG based on dynamic drawable name

Question

How to set image from PNG based on dynamic drawable name?

I use following code byt getting the error.

I have PNGs:

R.drawable.model_1.png
R.drawable.model_2.png
... and etc

Code

try
{
    String imageName = "model_" + uv.categoryID;
    int id = context.getResources().getIdentifier(imageName, "drawable", context.getPackageName());
    imageView.setImageResource(id);
}
catch(Exception ex)
{
    Log.e(TAG, ex);
}

Error

Attempt to invoke virtual method 'void android.widget.ImageView.setImageResource(int)' on a null object reference

Possible duplicate of [What is a NullPointerException, and how do I fix it?](https://stackoverflow.com/questions/218384/what-is-a-nullpointerexception-and-how-do-i-fix-it) — AskNilesh, Dec 21 '17 at 06:35

score 2 · Answer 1 · edited Dec 21 '17 at 06:43

2

It seems that you forgot to bind the ImageView.

imageView = (ImageView) findViewById(R.id.image_view_id);

edited Dec 21 '17 at 06:43

AskNilesh

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answered Dec 21 '17 at 06:26

Tenten Ponce

2,436
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40

2

You should use `context.findViewById(R.id.image_view_id);` .And it was more better.Because he use `context.getResources().getIdentifier` . – KeLiuyue Dec 21 '17 at 06:32
I assume that he's doing this on an activity. Well that's another optional answer. Thanks for suggesting. – Tenten Ponce Dec 21 '17 at 06:34

score 2 · Answer 2 · answered Dec 21 '17 at 06:42

Try this:

    try
    {
        ImageView imageView = (ImageView)findViewById(R.id.imageView);
        int categoryID = 0;
        String imageName = "model_" + categoryID;
        int id = this.getResources().getIdentifier(imageName, "drawable", this.getPackageName());
        imageView.setImageResource(id);
    }
    catch(Exception ex)
    {
        Log.e("NIKHIL", ex.toString());
    }

score 1 · Accepted Answer · edited Dec 21 '17 at 06:41

1

Try this you forgot to bind the imageView.

try
 {
    ImageView imageView = (ImageView) findViewById(R.id.Yourimageview);
    String imageName = "model_" + uv.categoryID;
    int id = context.getResources().getIdentifier(imageName, "drawable", context.getPackageName());
    imageView.setImageResource(id);
 }
 catch(Exception ex)
 {
     Log.e(TAG, ex);
 }

edited Dec 21 '17 at 06:41

AskNilesh

67,701
16
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163

answered Dec 21 '17 at 06:30

Ratilal Chopda

4,162
4
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31

How to set image from PNG based on dynamic drawable name

3 Answers3