随机切换案例

Question

你好朋友我有2种情况，但我想随便做。当用户单击按钮时，有2个情况case0或case1随机更改。所以文字也随机改变......

* lastImageName和lastImageName2是变量字符串......

Random rand = new Random();
int newrand = rand.nextInt(1) + 1;

switch(newrand) {
case 0:
    text1.setText(lastImageName);
    text2.setText(lastImageName2);
    break;
case 1:
    text1.setText(lastImageName2);
    text2.setText(lastImageName);
    break;
}

但有时候不工作......兰特是什么。问题

Answer 1

Random rand = new Random();
int a = 0;
int b = 1;
int c = random.nextBoolean() ? a : b;

Answer 2

删除+1。就这样做：int newrand = rand.nextInt(2);

Answer 3

Random#nextInt(int)生成一个介于0和0之间的随机数。即，nextInt(1)将始终返回0。相反，你应该使用：

int newrand = rand.nextInt(2);

Answer 4

如果您只有两个案例，请使用

boolean state = rand.nextBoolean();
text1.setText(state?lastImageName:lastImageName2);
text2.setText(state?lastImageName2:lastImageName);

对于多个，您也可以使用

Random rand = new Random();
int newrand = rand.nextInt() % count;//count = 2 for your case

switch(newrand) {
case 0:
    text1.setText(lastImageName);
    text2.setText(lastImageName2);
    break;
case 1:
    text1.setText(lastImageName2);
    text2.setText(lastImageName);
    break;
}