如何基于整数值执行代码

Question

I have an int, int minion1Hp , which can be a value of 0 -> 20. Depending on the value it is, a certain image resource will be set for an ImageView , using bar1.setImageResource(R.drawable.hpa); . However, my code currently looks like this:

    if (minion1Hp == 0) {
        bar1.setImageResource(R.drawable.hp);
    }
    if (minion1Hp == 1) {
        bar1.setImageResource(R.drawable.hpa);
    }
    if (minion1Hp == 2) {
        bar1.setImageResource(R.drawable.hpb);
    }
    if (minion1Hp == 3) {
        bar1.setImageResource(R.drawable.hpc);
    }
    if (minion1Hp == 4) {
        bar1.setImageResource(R.drawable.hpd);
    }
    if (minion1Hp == 5) {
        bar1.setImageResource(R.drawable.hpe);
    }

... and so on. Is there a more efficient way of doing this, rather than a long list of if statements?

Answer 1

Suggestion: initialize a map at startup (say in onCreate() ). Like this:

mDrawables = new HashMap<Integer, Integer>();
mDrawables.put(0, R.drawable.hp);
mDrawables.put(1, R.drawable.hpa);
...

then just do:

bar1.setImageResource(mDrawables.get(minion1Hp));

Answer 2

You can use a switch statement with a separate case for each instance. On a side note, you shouldn't be using just if statements up there, your code will run slowly, you should be using else if to make it run faster (since your hp can never be 1 and 2 at the same time.

Ex for switch statements:

switch (minion1Hp){ case 1: bar1.setImageResource(R.drawable.hp); break; case 2: bar1.setImageResource(R.drawable.hpa); break;

etc.

http://docs.oracle.com/javase/tutorial/java/nutsandbolts/switch.html

Answer 3

这里的改进是改变每个if第一个到后else if为minion1Hp不能在同一时间多个值，但你可能会发现它稍微整洁有在整个事情switch-case块来代替。