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If I want to change a image to another by the click of a button and then back to the previous image again by the click of the same button on imageview in android studio how to do that in short and easiest way? As I am new to it I am not familiar with all the functions of imageview.

For example:- I wrote this code to do what I needed after a lot of failure in finding a easier way.

int i=0;
public void change(View v){

    int img[] = {R.drawable.cat1,R.drawable.cat2};
    ImageView cat = findViewById(R.id.imageView2);
    if(i==0)
    {cat.setImageResource(img[1]);
    i=1;}
    else {cat.setImageResource(img[0]);
    i=0;}
 }

Before I was trying to do something like this:-

public void change(View v){

    ImageView cat = findViewById(R.id.imageView2);
    if(cat.getDrawable()==R.drawable.cat2;)
    {cat.setImageResource(R.drawable.cat1);}
 else
    {cat.setImageResource(R.drawable.cat1};
}

But it kept giving error that they have different type and I also tried some other functions named getId() but it didnt work either... So my main objective is, is there a function through which I can campare the resource of image view directly with the image in drawable folder and how to implement it in if else or some other conditional statement?

Preyum Kumar
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  • You mean, the first snippet of code gives you error? It looks fine and a good way to achieve your goal. What error message you got using that? – skafle Jul 16 '21 at 03:03
  • No the first snippet is how i did it but it seems big and has lots of lines. – Preyum Kumar Jul 16 '21 at 03:06
  • I am asking for any kind of function similar to that I tried in second part so that the code could become small and simple – Preyum Kumar Jul 16 '21 at 03:07
  • Apart from using a boolean, that approach can't be made much simpler. It does however not survive rotation. – Henry Twist Jul 16 '21 at 03:08

2 Answers2

0

The first approach should work, but the i value seems not tightly coupled to the ImageView. So, instead you can set a tag to the ImageView that equals to the current drawable id:

Initial tag:

ImageView cat = findViewById(R.id.imageView2);
cat.setImageResource(R.drawable.cat1);
cat.setTag(R.drawable.cat1);

And click listener callback:

public void change(View v){

    ImageView cat = findViewById(R.id.imageView2);
    int tag = (int) cat.getTag();
    
    if(tag == R.drawable.cat2){
        cat.setImageResource(R.drawable.cat1);
        cat.setTag(R.drawable.cat1);
        
    } else {
        cat.setImageResource(R.drawable.cat2);
        cat.setTag(R.drawable.cat2);
    }
    
}
Zain
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  • Yes I was in search of this .getTag() function that can compare the values in conditional statements without me having to set them in a array manually... Thanks :-) – Preyum Kumar Jul 16 '21 at 11:55
  • The first code works but I have to make an array of the things I want to compare And you gave the solution to it thanks now I dont have to do that. – Preyum Kumar Jul 16 '21 at 12:01
0

You could try StateListDrawable, LevelListDrawable, with each state/level, it will change image depend on your state/level

Steve.P
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