如何添加 NSArray 作为 NSMutableDictionary 键？

Question

我尝试执行以下操作：

NSMutableArray *myArr = [NSMutableArray arrayWithArray:[myDict objectForKey:@"myKey"]];
[myArr addObject:@"New string xxx"];
[myDict setObject:myArr forKey:@"myKey"];
// Write to file (done successfully)

如您所见，我得到一个数组，该数组存储在 plist 中，键为 @"myKey"，向其中添加一些对象并希望将其重新记录在plist，当然还有一些额外的值。

问题是，我的 plist 上发生以下情况：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs$
<plist version="1.0">
<dict>
        <key>myKey</key>
        <array>
                <string>First entry on the plist</string>

                <array>
                    <string>First entry on the plist</string>
                    <string>New string xxx</string>
                </array>
        </array>
</dict>
</plist>

当然，所需的输出是：

<?xml version="1.0" encoding="UTF-8"?>
    <!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs$
    <plist version="1.0">
    <dict>
            <key>myKey</key>
            <array>
                    <string>First entry on the plist</string>
                    <string>New string xxx</string>
            </array>
    </dict>
    </plist>

Answer 1

您是否尝试过在再次设置之前调用[myDict removeObjectForKey:@"myKey"]？

Answer 2

其工作正常

NSMutableArray *myArr = [NSMutableArray arrayWithArray:[myDict objectForKey:@"myKey"]];
[myArr addObject:@"New string xxx"];
[myDict setObject:myArr forKey:@"myKey"];
[myDict writeToFile:@"/path/p.text" atomically:NO];
[myArr addObject:@"new object"];
[myDict setObject:myArr forKey:@"myKey"];
[myDict writeToFile:@"/path/p.text" atomically:NO];

输出：

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
    <key>myKey</key>
    <array>
        <string>New string xxx</string>
        <string>new object</string>
    </array>
</dict>
</plist>