CODEWITHSUNDEEP
javaandroid
Sergej Popov
Sergej Popov

Reputation: 3021

make variable name from other variable value

Basically I'm trying to automate process of 

mDrawable[0] = this.getResources().getDrawable(R.drawable.img0);
mDrawable[1] = this.getResources().getDrawable(R.drawable.img1);
mDrawable[2] = this.getResources().getDrawable(R.drawable.img2);
mDrawable[3] = this.getResources().getDrawable(R.drawable.img3);
mDrawable[4] = this.getResources().getDrawable(R.drawable.img4);

etc..

to a loop:

for(int i = 0;i<=15;i++)
{       
mDrawable[i] = this.getResources().getDrawable(R.drawable.**img+i**);       
}

So how do I make up this resource name img4 from i loop variable

Thanks!

Upvotes: 1

Views: 286

Answers (4)

FunkTheMonk
FunkTheMonk

Reputation: 10938

To avoid Resource.getIndentifier() (the use of which is discouraged), you could generate an array of ids and iterate through them

int ids[] = { R.drawable.img0, R.drawable.img1, R.drawable.differentnames, R.drawable.whatever /*etc*/ };
mDrawables = new Drawable[ids.length];
for(int i = 0, s = ids.length; i < s; i++)
{       
    mDrawables[i] = this.getResources().getDrawable(ids[i]);       
}

Upvotes: 0

Paresh Mayani
Paresh Mayani

Reputation: 128428

I am sure you want to implement this kind of example.

This is helpful when you want to implement findViewById() inside a loop when there are many number of views with just a difference like "counter" varialbe 1, 2,3,4,5,etc.

for(int i=0; i<15; i++) 
{
    String imageID = "img" + (i);
    int resID = getResources().getIdentifier(imageID, "drawable", getPackageName());

  /* if you want to reference any widgets like Button, TextView, ImageView, etc. then write below code:

    //int resID = getResources().getIdentifier(imageID, "id", getPackageName());   
  */
}

Upvotes: 3

user658042
user658042

Reputation:

You can make use of Resources.getIdentifier()

Small snippet from the top of my head:

for(int i = 0;i<=15;i++)
{   
    int id = this.getResources().getIdentifier("img"+i, "drawable", getPackageName());
    mDrawable[i] = this.getResources().getDrawable(id);       
}

Upvotes: 2

John B
John B

Reputation: 32949

Reflection. However, given the overhead of doing the reflection I would suggest with sticking with the above code unless you have a lot more than 4 elements.

Post

Reflection

Upvotes: 0

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