我有这个JSON对象,我想访问“持续时间”,用显示它在控制台上Qt来访问JSON的元素:如何使用Qt
{
"kind": "youtube#videoListResponse",
"etag": "\"cbz3lIQ2N25AfwNr-BdxUVxJ_QY/brZ0pmrmXldPPKpGPRM-8I4dDFQ\"",
"pageInfo": {
"totalResults": 1,
"resultsPerPage": 1
},
"items": [
{
"kind": "youtube#video",
"etag": "\"cbz3lIQ2N25AfwNr-BdxUVxJ_QY/PkTW6UN9MH0O2kDApjC3penIiKs\"",
"id": "WkC18w6Ys7Y",
"contentDetails": {
"duration": "PT58M21S",
"dimension": "2d",
"definition": "hd",
"caption": "false",
"licensedContent": true,
"projection": "rectangular"
}
}
]
}
我的Qt代码是这样的:
{
QJsonDocument jsonResponse = QJsonDocument::fromJson(message);
results = jsonResponse.object();
QJsonValue v1 = results.value("items");
qDebug() << "v1 = " << v1;
QJsonValue v2 = v1.toObject().value("contentDetails");
qDebug() <<"v2 = " << v2;
QString v3 = v2.toObject().value("duration").toString();
qDebug() << "v3 = " << v3;
}
但是我的输出是:
V1 = QJsonValue(数组,QJsonArray([{ “contentDetails”:{ “标题”: “假”, “定义”: “HD”, “尺寸”:“2D “ ”持续时间“: ”PT58M21S“, ”licensedContent“:真, ”投影“: ”矩形“}, ”ETAG“:” \ “cbz3lIQ2N25AfwNr-BdxUVxJ_QY/PkTW6UN9MH0O2kDApjC3penIiKs \””, “ID”: “WkC18w6Ys7Y”, “种类”: “的YouTube#视频”}]))
V2 = QJsonValue(未定义)
V3 = “”
所以v1很好,但v2变得不确定。我做错了什么,我怎么才能正确访问“持续时间”项目?