xcode 将 NSString 转换为 NSDecimalNumber
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原文地址: http://stackoverflow.com/questions/14371907/
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Convert NSString to NSDecimalNumber
提问by StreaminJA
In my Core Data model, "amount" is an attribute in entity "Tracking". How do I convert amount to NSDecimalNumber throughout the code? I'm sure someone with more experience can do this in 3 minutes where I have been looking at it for days.
在我的 Core Data 模型中，“amount”是实体“Tracking”中的一个属性。如何在整个代码中将数量转换为 NSDecimalNumber？我相信有更多经验的人可以在 3 分钟内完成这件事，而我已经看了好几天了。
- (IBAction)save {
if (![amount.text isEqualToString:@""]) {
Tracking *tracking = [NSEntityDescription insertNewObjectForEntityForName:@"Tracking"
inManagedObjectContext:self.managedObjectContext];
NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
NSEntityDescription *weightEntity = [NSEntityDescription entityForName:@"Tracking" inManagedObjectContext:self.managedObjectContext];
[fetchRequest setEntity:weightEntity];
NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:@"timestamp" ascending:NO];
[fetchRequest setSortDescriptors:[NSArray arrayWithObject:sortDescriptor]];
NSError *error = nil;
NSArray *result = [self.managedObjectContext executeFetchRequest:fetchRequest error:&error];
Tracking *person = [result objectAtIndex:0];
NSLog(@"%@",person.date);
NSDate *date = [NSDate date];
NSDateFormatter *dateFormat = [[NSDateFormatter alloc]init];
[dateFormat setDateFormat:@"MMM dd, yyyy"];
NSString *dateString = [dateFormat stringFromDate:date];
//NSString *dateString = @"Jan 13 2013";
//Tracking *track = [self.fetchedResultsController objectAtIndexPath:nil];
tracking.note = note.text;
tracking.amount = amount.text;
tracking.title = [segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex];
tracking.date = dateString;
tracking.timestamp = date;
if (![person.date isEqualToString:dateString]) {
if ([[segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex] isEqualToString:@"Food/Drink"]) {
tracking.pic = @"Drink";
tracking.total = [NSString stringWithFormat:@"%.2f", 0.00 - [amount.text floatValue]];
NSLog(@"%f",[person.total floatValue]);
NSLog(@"%f", [amount.text floatValue]);
//tracking.total = @"1000.00";
}
else if ([[segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex] isEqualToString:@"Other"]) {
tracking.total = [NSString stringWithFormat:@"%.2f",0.00 - [amount.text floatValue]];
tracking.pic = [segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex];
}
else {
tracking.pic = [segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex];
tracking.total = [NSString stringWithFormat:@"%.2f",0.00 + [amount.text floatValue]];
}
}
else {
if ([[segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex] isEqualToString:@"Food/Drink"]) {
tracking.pic = @"Drink";
tracking.total = [NSString stringWithFormat:@"%.2f",[person.total floatValue] - [amount.text floatValue]];
NSLog(@"%f",[person.total floatValue]);
NSLog(@"%f", [amount.text floatValue]);
//tracking.total = @"1000.00";
}
else if ([[segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex] isEqualToString:@"Other"]) {
tracking.total = [NSString stringWithFormat:@"%.2f",[person.total floatValue] - [amount.text floatValue]];
tracking.pic = [segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex];
}
else {
tracking.pic = [segmentedChoice titleForSegmentAtIndex:segmentedChoice.selectedSegmentIndex];
tracking.total = [NSString stringWithFormat:@"%.2f",[person.total floatValue] + [amount.text floatValue]];
}
}
NSLog(@"\n Title: %@ \n Amount: %@ \n Note: %@ \n Date: %@ \n Picture: %@.png \n Total: %@ \n TimeStamp: %@", tracking.title, tracking.amount, tracking.note,tracking.date,tracking.pic, tracking.total, tracking.timestamp);
[self.managedObjectContext save:nil];
/* UIAlertView *alert = [[UIAlertView alloc] initWithTitle:[NSString stringWithFormat:@"%@ Saved",tracking.title] message:[NSString stringWithFormat:@"Amount: %@ \n Note: %@",tracking.amount,tracking.note] delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil, nil];
[alert show];*/
[amount resignFirstResponder];
[note resignFirstResponder];
[self dismissViewControllerAnimated:YES completion:nil];
}
回答by gerrytan
NSDecimalNumber has following method which you can use to convert your NSString into it:
NSDecimalNumber 具有以下方法，您可以使用它来将您的 NSString 转换为它：
+ (NSDecimalNumber *)decimalNumberWithString:(NSString *)numericString
For example:
例如：
NSString *foo = @"1.0";
NSDecimalNumber *cow = [NSDecimalNumber decimalNumberWithString:foo];
Full reference of the class is available here: http://developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDecimalNumber_Class/Reference/Reference.html#//apple_ref/occ/cl/NSDecimalNumber
该类的完整参考可在此处获得：http: //developer.apple.com/library/mac/#documentation/Cocoa/Reference/Foundation/Classes/NSDecimalNumber_Class/Reference/Reference.html#//apple_ref/occ/cl/ NSDecimalNumber
回答by hd1
Here you go:
干得好：
NSString *order;
NSDecimalNumber *decimal = [NSDecimalNumber decimalNumberWithString:order];
