ios-objective-c中NSNumber問題

objective-c中NSNumber問題

爆出錯誤：

Incompatible pointer types assigning to 'UITextfield *_strong' from 'NSNumber *_strong

代碼：

.h文件

@property (weak, nonatomic) IBOutlet UITextField *initialBudget;
@property (weak, nonatomic) IBOutlet UITextField *expenses;
@property (weak, nonatomic) IBOutlet UITextField *timeSpent;
@property (weak, nonatomic) IBOutlet UITextField *incomePerHour

計算：

- (IBAction)calculateResults:(id)sender {
    double budget = [initialBudget.text doubleValue ];
    double expense = [expenses.text doubleValue];
    double time = [timeSpent.text doubleValue];
    double hourlyIncome = (budget - expense)/time;
    NSNumber *resultNumber = [[NSNumber alloc] initWithDouble:hourlyIncome];
    incomePerHour = resultNumber;
};

最佳回答：

問題出在這裡

incomePerHour = resultNumber;

incomePerHour為UITextField 類型,而resultNumber為 NSNumber 類型。這兩個不著邊的對象怎可相互轉換？

改成

incomePerHour.text=[NSString stringWithFormat:@"%f",hourlyIncome];