我想生成1到10之间的随机数.当用户点击"下一步"按钮时,必须打印一个随机问题,并且不能重复问题.问题是,有时问题是重复.任何人都可以帮助我或提供一些参考或教程吗?
- (IBAction)nextQuestion:(id)sender
{
NSInteger randomNum = arc4random() %10 ;
int countCounter= counter++;
[self.btnNext setTitle:@"Next" forState:UIControlStateNormal];
if(countCounter==4)
{
self.btnNext.hidden=YES;
self.btnQuizDone.hidden=NO;
}
switch ( arc4random()%10)
{
case 0:
{
NSLog(@"zero");
[lblQuestion setText:@"Q10:question number ten"];
}
break;
case 1:
{
NSLog(@"one");
[lblQuestion setText:@"Q2:question number two"];
}
break;
case 2:
{
NSLog(@"two");
[lblQuestion setText:@"Q6:question number six"];
}
break;
case 3:
{
NSLog(@"three");
[lblQuestion setText:@"Q5:question number five"];
}
break;
case 4:
{
NSLog(@"four");
[lblQuestion setText:@"Q3:question number three"];
}
break;
case 5:
{
NSLog(@"five");
[lblQuestion …Run Code Online (Sandbox Code Playgroud) 我想更改默认打印机名称,使用JavaScript代码,下面的代码成功打开打印对话框,但我想设置我们自己的打印机名称.客户端所有打印机名称都已将其保存在数据库中.可以静态或动态更改.
<!DOCTYPE html>
<html>
<head>
<script>
function printpage()
{
window.print();
}
</script>
</head>
<body>
<input type="button" value="Print this page" onclick="printpage()" />
</body>
</html>
Run Code Online (Sandbox Code Playgroud)
提前致谢