据说单独的NSArray被编辑副本污染 [英] Supposedly separate NSArray being contaminated by editing a copy

问题描述

我有一个TableView中有一些文本域，的值表示文本域都链接到特定的位置在一个二维数组（NSMutableArrays的NSArray的）。

I have a TableView with some TextFields in. The values of said TextFields are linked to certain positions in a 2D Array (NSArray of NSMutableArrays).

这是最初的清洁数组的定义是这样：

An initial clean array is defined as so:

self.cleanEditContents = @[
                      [@[@-1,@-1] mutableCopy],
                      [@[@0,@80] mutableCopy],
                      [@[@0,@500] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy],
                      [@[@-1,@-1] mutableCopy]
                      ];

此阵应该是分开从主动阵列，使得有源阵列可通过一个按钮preSS复位。

This array is supposed to be kept separate from the 'active' array, so that the active array can be reset on a button press.

我用 self.editContents = [self.cleanEditContents复制] 来设置有源阵列包括直接清洗后阵列填充和按钮上preSS

I use self.editContents = [self.cleanEditContents copy]; to set the active array both directly after the clean array is populated and on a button press.

有就是，即使我重置阵列并调用reloadData和setNeedsLayout（矫枉过正？可能），数字不重的问题。我试图输出相同位置的值在两个数组和事实证明，有源阵列所做的任何更改污染干净阵列。

There is a problem where even though I reset the array and call reloadData and setNeedsLayout (overkill? probably), the numbers don't reset. I tried outputting the values of the same position in both arrays and it turns out that any changes made to the active array contaminate the clean array.

推荐答案

复制不浅拷贝。换句话说， self.editContents 和 self.cleanEditContents 均引用同一​​套可变阵列。所以，如果你在一个更新一个可变数组，变化是出现在其他。

copy does a shallow copy. In other words, self.editContents and self.cleanEditContents both reference the same set of mutable arrays. So if you update a mutable array in one, the change is seen in the other.

要创建 self.editContents ，创建与内阵列的可变副本的新数组。

To create self.editContents, create a new array with mutable copies of the inner arrays.

NSMutableArray *tmp = [NSMutableArray array];
for (NSArray *array in self.cleanEditContents) {
    [tmp addObject:[array mutableCopy]];
}
self.editContents = tmp;

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