android 工作室更改背景图像为多个图像

Question

I have 5 images in the drawable folder (bg1, bg2, bg3, bg4, bg5), bg1 is my default background.

I want to change the the image of the background in order eatch time I click the button and when it arrive to the final image it should go again to the first image,

for example if I cliked the button it should set bg2 as background and if I clicked it again it should set bg3 as background and so on,

I tried the below code but it only change the background image one time.

    button.setOnClickListener(new View.OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub

            int x = 0;

            while(x < 5){

             x ++;
                // Give image name that you want to show on button click
                layout.setBackgroundResource(R.drawable.bg+x);

            }

        }
    });

Answer 1

You have to set x as a global variable. You set x in function so it is always 0 .

int x = 0; //global variable in activity/fragment

...

button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
              x ++;
              x %= 5;
              if (x==0) layout.setBackgroundResource(R.drawable.bg1);
              else if (x==1) layout.setBackgroundResource(R.drawable.bg2);
              else if (x==2) layout.setBackgroundResource(R.drawable.bg3);
              else if (x==3) layout.setBackgroundResource(R.drawable.bg4);
              else layout.setBackgroundResource(R.drawable.bg5);
            }

        }
    });

Answer 2

Try:

// declare the varibale globally, or else everytime the onClick is called it will be reset to 0 
int x = 1;

button.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
                int bg = 0;

                // are we larger than 5? lets start again at 1 :)
                if (x == 6) x = 1;

                if (x == 1) bg = R.drawable.bg1;
                if (x == 2) bg = R.drawable.bg2;
                if (x == 3) bg = R.drawable.bg3;
                if (x == 4) bg = R.drawable.bg4;
                if (x == 5) bg = R.drawable.bg5;

                layout.setBackgroundResource(bg);

                // lets increment you for the next round
                x++;
            }
        }
    });