为什么UITableViewCell中不能反映NSUserDefault中存储为Object的Double值？

Question

I am trying to store Double Value in NSUserDefault But though i am able to store it (as my NSLog value shows true value), when I tried to reload UITableView, its Cell value is not updated with current value in userdefault.

This weird behavior happens only when i call my setUserDefaults method from delegate method of UIAlertView

Why such weird behavior happens??

Here is my code:

- (void)setUserDefaults
{
    NSLog(@"setUserDefault : empArray: %d, empCount: %d",empArray.count, empCount);
    NSMutableDictionary *empData = [[NSMutableDictionary alloc] init];
    if (empArray.count>1)
        empData = [empArray objectAtIndex:(empCount-1)];   // because empCount starts from 1. and empArray[0] = empCount 1
    else
        empData = [empArray objectAtIndex:0];

    [userDefault setObject:[NSString stringWithFormat:@"%.2f",[empData objectForKey:@"salary"]] forKey:@"salary"];
    NSLog(@"setUserDefaults: salary=%.2f",[[empData objectForKey:@"salary"] doubleValue]);

    [empData release];

    [self.tblView reloadData];
}

Delegate method of UIAlertView goes as below:

-(void) alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger) buttonIndex
{
    if (alertView.tag == 1)    // btnRemoveEmpPressed. 
    {
        if(buttonIndex==0)
        {
            NSLog(@"buttonIndex 0");
        }
        else
        {
            NSLog(@"empRemovedPressed OK, buttonIndex 1, empArray Count %d, empCount %d",empArray.count, empCount);
            //        [empArray removeObjectAtIndex:(empCount)];
            empCount -= 1;
            lblTitle.text = [NSString stringWithFormat:@"Employee %d",empCount];
            [self setUserDefaults];
        }
//        [tblView reloadData];
    }
    else if (alertView.tag == 2)
    {
        if (buttonIndex==1)
        {
            [self resetUserDefaults];
            empCount = 1;
            [empArray removeAllObjects];
            lblTitle.text = [NSString stringWithFormat:@"Employee %d",empCount];
        }
    }
}

Answer 1

You should use the setDouble:forKey: method of NSUserDefaults and let it manage the value for you. Also synchronize the NSUserDefaults in order to save the value for later usage.

Answer 2

• You aren't using doubleValue when setting user defaults. Either do that or, as herz says, use the setDouble method.
• You aren't calling synchronize on your defaults object after updating it
• Don't release empData, you didn't retain it
• I'm assuming userDefault is set up elsewhere and it is not nil when you are using it?