c# - 如何使用 NewtonSoft 在 C# 中从另一个 json 替换 json？

Question

我有两个 JSON 对象 -

json1 = {
    "payload": {
        "firstName": "John",
        "lastName": "Doe",
        "code": "test1",
        "arrayProp1": [1, 2, 3],
        "arrayProp2": [{
                "prop1": "value1",
                "prop2": "value2"
            },
            {
                "prop1": "2_value1",
                "prop2": "2_value2"
            }
        ]
    }
}

json2 = {
    "payload": {
        "code": "newCode",
        "arrayProp1": [3,4],
        "arrayProp2": [{
                "prop1": "newValue1",
                "prop2": "newValue2"
            }
        ]
    }
}

如果我使用内置合并 (json1.Merge(json2))，得到的结果是 -

result : {
    "payload": {
        "firstName": "John",
        "lastName": "Doe",
        "code": "newCode",
        "arrayProp1": [1, 2, 3, 3, 4],
        "arrayProp2": [{
                "prop1": "value1",
                "prop2": "value2"
            },
            {
                "prop1": "newValue1",
                "prop2": "newValue2"
            },
            {
                "prop1": "2_value1",
                "prop2": "2_value2"
            }
        ]
    }
}

预期结果-

{
    "payload": {
        "firstName": "John",
        "lastName": "Doe",
        "code": "newCode",
        "arrayProp1": [3, 4],
        "arrayProp2": [{
            "prop1": "newValue1",
            "prop2": "newValue2"
        }]
    }
}

我想根据 json2 中提供的值替换 json1 的父属性值。

我尝试编写一个函数，这是我的当前版本 -

string Merge(string req1, string req2) {
    try
                {
                    JObject json1 = JObject.Parse(req1);
                    JObject json2 = JObject.Parse(req2);                
    
                    foreach (var a in json2.DescendantsAndSelf())
                    {
                        if (a is JObject obj)
                        {
                            foreach (var prop in obj.Properties())
                            {
                                if(json1.SelectTokens(prop.Path).Any())
                                {
                                    json1[prop.Path] = prop.Value;
                                }
                            }
                        }
                        
                    }
                    req1 = json1.ToString();
                }
                catch(Exception ex)
                {
                    //do nothing
                }
return req1; }

这里有2个问题-

1. “payload”被识别为属性，json1 被 json2 完全替换，因此我失去了它的一些属性。
2. 被替换后，当循环继续运行时，说要更新属性'code'，则属性路径为payload.code，所以在json1[prop.path] = prop.Value这一行，而不是更新有效负载中的现有代码，它创建一个名为 payload.code 的新属性，值为“newcode”

上面代码的最终结果是——

{
    "payload": {
        "code": "newCode",
        "arrayProp1": [3, 4],
        "arrayProp2": [{
            "prop1": "newValue1",
            "prop2": "newValue2"
        }],
        "payload.code": "newCode",
        "payload.arrayProp1": [3, 4],
        "payload.arrayProp2": [{
            "prop1": "newValue1",
            "prop2": "newValue2"
        }],
        "payload.arrayProp1[0].prop1": "newValue1",
        "payload.arrayProp1[0].prop2": "newValue2"
    }
}

有人可以帮我解决这个问题吗？

Answer 1

您的要求是，在使用 JContainer.Merge() 合并两个 JSON 对象时，数组内容被替换而不是连接起来.您可以通过 JsonMergeSettings.MergeArrayHandling 实现此目的设置，具有以下 values :

Concat   0   Concatenate arrays.
Union    1   Union arrays, skipping items that already exist.
Replace  2   Replace all array items.
Merge    3   Merge array items together, matched by index. 

具体来说，MergeArrayHandling.Replace 将按要求工作:

json1.Merge(json2, new JsonMergeSettings 
            { 
                MergeArrayHandling = MergeArrayHandling.Replace 
            });

演示 fiddle here .