Qt 中 QVariantMap 的使用教程 - 存储和访问键值对

QVariantMap \u662f Qt \u4e2d \u7684 \u4e00 \u4e2a \u7c7b\uff0c\u7528\u4e8e \u5b58\u50a8 \u952e\u503c\u5bf9\u7684 \u5f71\u64ce\u5173\u7cfb\u3002\u5b83\u7c7b\u4f3c\u4e8e C++ \u4e2d\u7684 std::map \u6216\u8005 Python \u4e2d\u7684 \u8bcd\u5178\u3002\n\n\u4f7f\u7528 QVariantMap \u53ef\u4ee5 \u65b9\u4fbf\u7684 \u5b58\u50a8 \u548c \u8bbf\u95ee \u591a\u4e2a \u4e0d\u540c\u7c7b\u578b\u7684 \u503c\u3002\u4e0b\u9762 \u662f \u4e00\u4e9b QVariantMap \u7684 \u5e38\u89c1 \u7528\u6cd5\uff1a\n\n1\uff0e \u521b\u5efa QVariantMap \u5bf9\u8c61\uff1a\n\tcpp\n\tQVariantMap map;\n\t\n\n2\uff0e \u5411 QVariantMap \u4e2d \u63d2\u5165 \u952e\u503c\u5bf9\uff1a\n\tcpp\n\tmap.insert("name", "John");\n\tmap.insert("age", 25);\n\tmap.insert("isStudent", true);\n\t\n\n3\uff0e \u8bbf\u95ee QVariantMap \u4e2d\u7684 \u503c\uff1a\n\tcpp\n\tQString name = map["name"].toString();\n\tint age = map["age"].toInt();\n\tbool isStudent = map["isStudent"].toBool();\n\t\n\n4\uff0e \u68c0\u67e5 QVariantMap \u4e2d \u662f\u5426 \u5b58\u5728 \u67d0\u4e2a \u952e\uff1a\n\tcpp\n\tif (map.contains("name")) {\n\t // do something\n\t}\n\t\n\n5\uff0e \u83b7\u53d6 QVariantMap \u4e2d\u7684 \u952e\u5217\u8868\uff1a\n\tcpp\n\tQList<QString> keys = map.keys();\n\t\n\n6\uff0e \u83b7\u53d6 QVariantMap \u4e2d\u7684 \u503c\u5217\u8868\uff1a\n\tcpp\n\tQList<QVariant> values = map.values();\n\t\n\n7\uff0e \u901a\u8fc7 QVariantMap \u4e2d\u7684 \u6240\u6709 \u952e\u503c\u5bf9\uff1a\n\tcpp\n\tforeach (const QString& key, map.keys()) {\n\t QVariant value = map.value(key);\n\t // do something with key and value\n\t}\n\t\n\n8\uff0e \u5220\u9664 QVariantMap \u4e2d\u7684 \u67d0\u4e2a \u952e\u503c\u5bf9\uff1a\n\tcpp\n\tmap.remove("age");\n\t\n\n9\uff0e \u6e05\u7a7a QVariantMap \u4e2d\u7684 \u6240\u6709 \u952e\u503c\u5bf9\uff1a\n\tcpp\n\tmap.clear();\n\t\n\n\u9700\u8981 \u6ce8\u610f\u7684\u662f\uff0cQVariantMap \u4e2d\u7684 \u503c\u53ef\u4ee5 \u662f \u4efb\u610f\u7c7b\u578b\u7684 QVariant \u5bf9\u8c61\uff0c\u5305\u62ec \u57fa\u672c\u7c7b\u578b\u3001\u81ea\u5b9a\u4e49\u7c7b\u548c\u5176\u4ed6\u5bb9\u5668\u7c7b\u3002\u5728 \u4f7f\u7528 QVariantMap \u65f6\uff0c\u9700\u8981 \u6839\u636e \u5b9e\u9645\u60c5\u51b5 \u8fdb\u884c \u7c7b\u578b\u8f6c\u6362 \u548c \u9519\u8bef\u5904\u7406\u3002