c++ - QJsonObject の変更方法

Question

単純な json ファイルで、この方法でオブジェクトに値を設定できます。

Qt コード:

if(file.open(QIODevice::ReadOnly)){
    QJsonDocument doc = QJsonDocument::fromJson(file.readAll());
    QJsonObject obj = doc.object();
    obj["gender"] = "female";
    doc.setObject(obj);
    manager.put(request, doc.toJson());
}

シンプルな json ファイル:

{
    "resourceType": "Patient",
    "gender": "male",
    "birthDate": "2018-08-21"
}

したがって、このコードは性別の値を女性に変更します。

しかし、「オブジェクトの下にオブジェクト」がある大きなjsonを使用すると

{
    "resource": {
        "resourceType": "Patient",
        "id": "530f8eb0-1f0b-41b0-b94",
        "text": {
            "status": "generated",
            "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">Teppo Testman\n            <a name=\"mm\"></a>\n          </div>"
        },
        "name": [{
            "family": "Testman",
            "given": [
                "Teppo"
            ]
        }],
        "gender": "male",
        "birthDate": "1993-02-12"
    }
}

アップデート：

{
    "resourceType": "Bundle",
    "id": "17772d63-3b14-494f-8182-06b67c970550",
    "meta": {
        "versionId": "1",
        "lastUpdated": "2018-08-15T12:08:48.036+00:00"
    },
    "type": "collection",
    "entry": [{
            "resource": {
                "resourceType": "Observation",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">Height\n            <a name=\"mm\"></a>\n          </div>"
                },
                "status": "final",
                "code": {
                    "coding": [{
                        "system": "http://loinc.org",
                        "code": "8302-2",
                        "display": "Body height"
                    }]
                },
                "subject": {
                    "reference": "Patient/530f8eb0-1f0b-41b0-b94b-c25a14656645"
                },
                "valueQuantity": {
                    "value": 166,
                    "unit": "cm"
                }
            }
        },
        {
            "resource": {
                "resourceType": "Observation",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">BMI\n            <a name=\"mm\"></a>\n          </div>"
                },
                "status": "final",
                "code": {
                    "coding": [{
                        "system": "http://loinc.org",
                        "code": "39156-5",
                        "display": "Body mass index (BMI) [Ratio]"
                    }]
                },
                "subject": {
                    "reference": "Patient/530f8eb0-1f0b-41b0-b94b-c25a14656645"
                },
                "valueString": "23"
            }
        },
        {
            "resource": {
                "resourceType": "Observation",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">FEV1 [l]\n            <a name=\"mm\"></a>\n          </div>"
                },
                "status": "final",
                "code": {
                    "coding": [{
                        "system": "http://loinc.org",
                        "code": "18759-1",
                        "display": "Spirometry study"
                    }]
                },
                "subject": {
                    "reference": "Patient/530f8eb0-1f0b-41b0-b94b-c25a14656645"
                },
                "valueQuantity": {
                    "value": 2,
                    "unit": "l"
                }
            }
        },
        {
            "resource": {
                "resourceType": "Observation",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">FEV6 [l]\n            <a name=\"mm\"></a>\n          </div>"
                },
                "status": "final",
                "code": {
                    "coding": [{
                        "system": "http://loinc.org",
                        "code": "18759-1",
                        "display": "Spirometry study"
                    }]
                },
                "subject": {
                    "reference": "Patient/530f8eb0-1f0b-41b0-b94b-c25a14656645"
                },
                "valueQuantity": {
                    "value": 2.9,
                    "unit": "l"
                }
            }
        },
        {
            "resource": {
                "resourceType": "Observation",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">PEF [l/s]\n            <a name=\"mm\"></a>\n          </div>"
                },
                "status": "final",
                "code": {
                    "coding": [{
                        "system": "http://loinc.org",
                        "code": "18759-1",
                        "display": "Spirometry study"
                    }]
                },
                "subject": {
                    "reference": "Patient/530f8eb0-1f0b-41b0-b94b-c25a14656645"
                },
                "valueQuantity": {
                    "value": 6.5,
                    "unit": "l/s"
                }
            }
        },
        {
            "resource": {
                "resourceType": "Patient",
                "id": "530f8eb0-1f0b-41b0-b94b-c25a14656645",
                "text": {
                    "status": "generated",
                    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\">Teppo Testman\n            <a name=\"mm\"></a>\n          </div>"
                },
                "name": [{
                    "family": "Testman",
                    "given": [
                        "Teppo"
                    ]
                }],
                "gender": "male",
                "birthDate": "1993-02-12"
            }
        }
    ]
}

値を変更できません。それを行う簡単な方法はありますか？私は解決策を見つけようとしましたが、成功しませんでした!