Iphone 如果UITextField为空,则显示UIAlert
我只想做的是,如果Iphone 如果UITextField为空,则显示UIAlert,iphone,ios,ios5,Iphone,Ios,Ios5,我只想做的是,如果UITextField上没有任何内容,应用程序将显示一个警报。我不明白我做错了什么。这是我的密码: - (IBAction)Calculate:(id)sender { /*If there is nothing on textfield, it will show an alert*/ if ([addtake.text length] && [Subtake.text length] == 0) { UI
UITextField
上没有任何内容,应用程序将显示一个警报。我不明白我做错了什么。这是我的密码:
- (IBAction)Calculate:(id)sender {
/*If there is nothing on textfield, it will show an alert*/
if ([addtake.text length] && [Subtake.text length] == 0)
{
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"Alert"message:@"Empty TextField not allowed" delegate:nil cancelButtonTitle:@"Okay" otherButtonTitles: nil];
[myAlert show];
}
else{
NSString *Adding =[addtake text];
NSInteger number = [Adding intValue]; /*Converting String to int*/
NSInteger new = 5 + number;
NSString *newString = [NSString stringWithFormat:@"%d",new];
[myAdd setText:newString];
/*Subtruct*/
NSString *Subtruct =[Subtake text];
NSInteger SubNumber = [Subtruct intValue];
NSInteger newSub = 10 - SubNumber;
NSString *newSubString = [NSString stringWithFormat:@"%d",newSub];
[mySub setText:newSubString];
[addtake resignFirstResponder];
[Subtake resignFirstResponder];
}
}
我假设addText是您的tesxField,因此您还需要设置条件[addtake.text length]==0 我假设addText是您的tesxField,因此您还需要设置条件[addtake.text length]==0 尝试将if语句中的每一个子条款都显式化—如果只是为了可读性
if ([addtake.text length] == 0 && [Subtake.text length] == 0)
我会在你的测试中使用逻辑OR,而不是逻辑AND。因此,如果任一文本字段为空,则会显示警报
if ((![addtake.text length]) || (![Subtake.text length]))
{
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"Alert"message:@"Empty TextField not allowed" delegate:nil cancelButtonTitle:@"Okay" otherButtonTitles: nil];
[myAlert show];
}
尝试将if语句中的每个子条款显式化-如果只是为了可读性 我会在你的测试中使用逻辑OR,而不是逻辑AND。因此,如果任一文本字段为空,则会显示警报
if ((![addtake.text length]) || (![Subtake.text length]))
{
UIAlertView *myAlert = [[UIAlertView alloc]initWithTitle:@"Alert"message:@"Empty TextField not allowed" delegate:nil cancelButtonTitle:@"Okay" otherButtonTitles: nil];
[myAlert show];
}
哪个文本字段?addtake还是Subtake?哪个文本字段?addtake还是Subtake?是的,这是最好的解决方案:-)是的,这是最好的解决方案:-)