我希望 if 语句在 12 分钟或超过 12 分钟时起作用，但我不断收到错误消息，说"Type mismatch: cannot convert from int to boolean"

Question

我希望 if 语句在 12 分钟或过去 12 分钟时运行，但我不断收到错误"类型不匹配：无法从 int 转换为布尔值"，我该如何解决这个问题？

public void clock() {
Thread cloo = new Thread() {
public void run() {
try {
while (true) {
Calendar cal = new GregorianCalendar();
int day = cal.get(Calendar.DAY_OF_MONTH);
int hour = cal.get(Calendar.HOUR);
int min = cal.get(Calendar.MINUTE);
int second = cal.get(Calendar.SECOND);
lblNewLabel_1.setText(day + "/ " + hour + ":" + min + ":" + second);
sleep(1000);
if (min =+ 12) { // <<<<< where the problem is
message.setText("its been over 12 minutes");
}
}
}
}
}
}

Answer 1

if表达式只接受boolean值，但min =+ 12是int值，因此会发生类型不匹配。

试试这个：

int countdown = 12;
while (true) {
Calendar cal = new GregorianCalendar();
int day = cal.get(Calendar.DAY_OF_MONTH);
int hour = cal.get(Calendar.HOUR);
int min = cal.get(Calendar.MINUTE);
int second = cal.get(Calendar.SECOND);
lblNewLabel_1.setText(day + "/ " + hour + ":" + min + ":" + second);
sleep(1000);
countdown = countdown - 1;
if (countdown <= 0) {
message.setText("its been over 12 minutes");
}
}

此外，根据您的编程设计，您应该决定当时间超过 12 分钟时该怎么做，停止它或重新倒计时？上面的代码将重复执行message.setText("its been over 12 minutes");。