java Next和Prev Buttons逻辑

Posted 2021-05-07

int i=0;

next.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

            if (i < List.size() - 1) {
                i = i + 1;
                //some tasks
            }
            if (i == List.size() - 1)
                Toast.makeText(MainActivity.this, "This is the last article", Toast.LENGTH_LONG).show();
    }
});

prev.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
            if (i > 0) {
                i = i - 1;
                //some tasks
            }
            if (i == 0)
                Toast.makeText(MainActivity.this, "This is the First article", Toast.LENGTH_LONG).show();
    }
});

int i=0;

next.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {

        if (i == List.size() - 1)
            i = -1;

        i = i + 1;
        if (i < List.size() && i > -1) {
            //some tasks
        }
    }
});

prev.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        if (i == 0)
            i = List.size();
            
        i = i - 1;
        if (i < List.size() && i > -1) {
            //some tasks
        }
    }
});