如何添加NSArray作为NSMutableDictionary的NSMutableDictionary密钥？

Question

我尝试了以下操作：

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

如你所见，我得到了一个数组，它用键@"myKey"存储在plist上，添加了一些对象，并希望在plist上重新记录它，当然还有一些额外的值。

问题是，在我的plist上会发生以下情况：

<?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，期望的输出是：

<?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

在重新设置之前，您是否尝试过调用[myDict removeObjectForKey:@"myKey"]？

Answer 2

它工作正常

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>