Question

我正在编写一个需要保存和恢复nsmutablearrays的应用程序来填充表格视图。数组将保存，但一旦重置所有内容将不会覆盖。我发现这些值组合在一起并且给了我不可靠的平均值...代码如下。我也有各种具有此圈功能的视图控制器......

 // code that adds items to table view and saves a version of the array to nsmutablearray
 NSUserDefaults *prefs = [[NSUserDefaults alloc]
                                 initWithSuiteName:@"group.com.DJ.TSTML"];


        [tableItems3 insertObject:TimeString2 atIndex:0];
        // time string is the time as a nsstring
        [tableItems4 addObject:[NSNumber numberWithFloat:seconds2]];

        [tableview reloadData];

        [prefs setObject:self.tableItems4 forKey:@"SavedArray3"];
        [prefs setObject:self.tableItems3 forKey:@"SavedArray4"];
        // this is saving to insurer defaults



        NSString *newString = [NSString stringWithFormat:@"%lu", (unsigned long)tableItems3.count];

        [Commentcount setText:newString];


        NSNumberFormatter *formatter = [[NSNumberFormatter alloc] init];

        NSNumber *average = [tableItems4 valueForKeyPath:@"@avg.self"];

        Average.text = [formatter stringFromNumber:average];


        NSLog(@"Sucess");

        [prefs synchronize];
    } }

恢复阵列：

        NSUserDefaults *prefs = [[NSUserDefaults alloc]
                         initWithSuiteName:@"group.com.DJ.TSTML"];

// code used to erase current values in the table view and restore from NSUserDefaults
        tableItems3 = [[NSMutableArray alloc] init];
        tableItems4 = [[NSMutableArray alloc] init];
        [tableview reloadData];


        NSMutableArray *RestoreArray1 = [[prefs objectForKey:@"SavedArray4"]mutableCopy];
        NSMutableArray *RestoreArray2 = [[prefs objectForKey:@"SavedArray3"]mutableCopy];

        [tableItems3 addObjectsFromArray:RestoreArray1];
        [tableItems4 addObjectsFromArray:RestoreArray2];
        if (tableItems3 == nil) {
            tableItems3 = [[NSMutableArray alloc] init];
            tableItems4 = [[NSMutableArray alloc] init];
        }
        [tableview reloadData];
        NSLog(@"%@",tableItems4);


    }
}

提前感谢您的帮助！我的问题要明确的是，每次我保存到nsuserdefaults而不是覆盖前一个数组时，它只保留旧数组并与新数组结合

Answer 1

好的，我回答了我自己的问题。有人提出它是因为我正在检索而不首先覆盖它。以下代码是有用的......

 NSString *Clearstring = [prefs objectForKey:@"Clear?"];
// i created a nsstring that when the method for restarting would change accordingly.
//  so when someone would navigate to this view controller this would fire.
// if clear is yes i would prevent the code that controled the restore function from restoring and prepare
//  it if it was needed to be restored again.
        if ([Clearstring isEqualToString:@"Yes"]) {
            tableItems3 = [[NSMutableArray alloc] init];
            tableItems4 = [[NSMutableArray alloc] init];

            [prefs setObject:self.tableItems4 forKey:@"SavedArray3"];
            [prefs setObject:self.tableItems3 forKey:@"SavedArray4"];
            [prefs setObject:@"NO" forKey:@"Clear?"];
            [tableview reloadData];

        }
        else{
        tableItems3 = [[NSMutableArray alloc] init];
        tableItems4 = [[NSMutableArray alloc] init];
        [tableview reloadData];

        NSMutableArray *RestoreArray1 = [[prefs objectForKey:@"SavedArray4"]mutableCopy];
        NSMutableArray *RestoreArray2 = [[prefs objectForKey:@"SavedArray3"]mutableCopy];
        [tableItems3 removeAllObjects];
        [tableItems4 removeAllObjects];

        [tableItems3 addObjectsFromArray:RestoreArray1];
        [tableItems4 addObjectsFromArray:RestoreArray2];
        if (tableItems3 == nil) {
            tableItems3 = [[NSMutableArray alloc] init];
            tableItems4 = [[NSMutableArray alloc] init];
        }
        [tableview reloadData];
        NSLog(@"%@",tableItems4);

        }
    }

将NSMutablearray保存并还原到NSUserdefaults

1 个答案: