maxmind/libmaxminddb

Qt. ubuntu x64, can't get coordinates

eds709394 opened this issue · 8 comments

eds709394 commented

MainWindow::MainWindow(QWidget *parent)
: QMainWindow(parent)
, ui(new Ui::MainWindow)
{
ui->setupUi(this);

MMDB_s mmdb;
MMDB_lookup_result_s result;
int gai_error;
int mmdb_error;
const char ip_address[] = "116.28.219.199"; // 要查询的 IP 地址

// 初始化 MMDB 结构
// GeoLite2-City.mmdb
// GeoIP2-City.mmdb
//if (MMDB_open("./GeoLite2-City.mmdb", MMDB_MODE_MMAP, &mmdb) == MMDB_SUCCESS)
if (MMDB_open("./GeoIP2-City.mmdb", MMDB_MODE_MMAP, &mmdb) == MMDB_SUCCESS)
{
    //MMDB_open("/GeoIP2-City.mmdb", MMDB_MODE_MMAP, &mmdb);
    // 查询 IP 地址的经纬度信息
    result = MMDB_lookup_string(&mmdb, ip_address, &gai_error, &mmdb_error);
    if (gai_error == 0 && mmdb_error == MMDB_SUCCESS)
    {
        MMDB_entry_data_s entry_data;

        if (result.found_entry)
        {
            if (MMDB_SUCCESS == MMDB_get_value(&result.entry, &entry_data, "location", "latitude", NULL, NULL)) {/* MMDB_get_value 成功 */
                if (entry_data.has_data) {/* 找到了想要的数据 */
                    if (entry_data.type == MMDB_DATA_TYPE_DOUBLE) {
                        printf("%lf", entry_data.double_value);
                        printf("\n");
                    }
                    else {
                        printf("data_type = %d\n", entry_data.type);
                    }
                }
                else {
                    fprintf(stderr, "MMDB_get_value not found\n");
                }
            }
        }

        char lat[16], lon[16];

        // 从查询结果中获取经度和纬度信息
        if (MMDB_get_value(&result.entry, &entry_data, "location/latitude", NULL) == MMDB_SUCCESS) {
            snprintf(lat, sizeof(lat), "%.6f", entry_data.double_value);
        }
        if (MMDB_get_value(&result.entry, &entry_data, "location/longitude", NULL) == MMDB_SUCCESS) {
            snprintf(lon, sizeof(lon), "%.6f", entry_data.double_value);
        }

        // 获取经纬度信息
        double latitude = 0.0;
        double longitude = 0.0;
        MMDB_get_value(&result.entry, &entry_data, "location", "latitude");
        latitude = entry_data.double_value;
        MMDB_get_value(&result.entry, &entry_data, "location", "longitude");
        longitude = entry_data.double_value;

        // 打印经纬度信息
        printf("Latitude: %f\n", latitude);
        printf("Longitude: %f\n", longitude);

        // 打印经度和纬度信息
        printf("IP地址：%s\n", ip_address);
        printf("经度：%s\n", lat);
        printf("纬度：%s\n", lon);
    } else {
        printf("无法查询IP地址的经纬度信息\n");
    }

    // 关闭 MMDB
    MMDB_close(&mmdb);
}

}

oschwald commented

I am not entirely sure what the question is, but I suspect the issue is that you need to replace:

        MMDB_get_value(&result.entry, &entry_data, "location", "latitude");
        latitude = entry_data.double_value;
        MMDB_get_value(&result.entry, &entry_data, "location", "longitude");
        longitude = entry_data.double_value;

with:

        MMDB_get_value(&result.entry, &entry_data, "location", "latitude", NULL);
        latitude = entry_data.double_value;
        MMDB_get_value(&result.entry, &entry_data, "location", "longitude", NULL);
        longitude = entry_data.double_value;
eds709394 commented

Can be compiled. But can't get the right value.

oschwald commented

Did you try the fix I proposed above? If so, what output are you getting and what output are you expecting?

eds709394 commented

Warning: Ignoring XDG_SESSION_TYPE=wayland on Gnome. Use QT_QPA_PLATFORM=wayland to run on Wayland anyway.
-124968807495796401245153016236126869777128867833808623288451205173435487563224681818285869834730626066856392915726039229981606467101545437276624551019756826905477527753855192786503238782004751359288074763272142991080518245834880389993883020296192.000000
Latitude: 0.000000
Longitude: 0.000000
IP地址：116.28.219.199
经度：讁���
纬度：��D���

eds709394 commented

Win7 x64, That's my expecting.

34.773200
Latitude: 34.773200
Longitude: 113.722000
IP鍦板潃锛16.28.219.199
缁忓害锛
绾害锛殺��X

oschwald commented
eds709394 commented

This project in windows is ok, but when I transplant to ubuntu...

oschwald commented

I'd suggest reaching out to support@maxmind.com for any additional help. The code seems to work fine for me on Ubuntu with the changes I outlined.