gdal字符编码

首先确认vs 中字符编码：也就是说，vs里 Encoding的 default=GBK

 

 中  用两个字节存储，十进制 214， 208 = 十六进制  D6 D0

 https://tool.lu/hexconvert/

 转换成 utf-8编码：即为十进制 228 184 173 = 十六进制 e4 b8 ad

 https://www.qqxiuzi.cn/bianma/zifuji.php

  

 转换回来，当然还是 中 字

GDAL里

        [DllImport("gdal303.dll", EntryPoint = "OGR_F_SetFieldString", CallingConvention = CallingConvention.Cdecl)]
        public extern static void OGR_F_SetFieldString(HandleRef handle, int index, string val);
        /// <param name="fe"></param>
        /// <param name="index">索引</param>
        /// <param name="val">值</param>
        public static void setFieldString(Feature fe, int index, string val)
        {
            OGR_F_SetFieldString(OSGeo.OGR.Feature.getCPtr(fe), index, val);
        }

  

获取字段属性值的乱码解决：

        [DllImport("gdal303.dll", EntryPoint = "OGR_Fld_GetNameRef", CallingConvention = CallingConvention.Cdecl)]
        public extern static System.IntPtr OGR_Fld_GetNameRef(HandleRef handle);


        [DllImport("gdal303.dll", EntryPoint = "OGR_F_GetFieldAsString", CallingConvention = CallingConvention.Cdecl)]
        public extern static System.IntPtr OGR_F_GetFieldAsString(HandleRef handle, int index);

        [DllImport("gdal303.dll", EntryPoint = "OGR_F_GetFieldAsBinary", CallingConvention = CallingConvention.Cdecl)]
        public extern static System.IntPtr OGR_F_GetFieldAsBinary(HandleRef handle, int index, out int byteCount);
        [DllImport("gdal303.dll", EntryPoint = "OGR_F_SetFieldString", CallingConvention = CallingConvention.Cdecl)]
        public extern static void OGR_F_SetFieldString(HandleRef handle, int index, string val);


        /// <param name="fe">当前要素</param>
        /// <param name="index">索引</param>
        /// <returns></returns>
        public static String getFieldAsStr(Feature fe, int index)
        {
            IntPtr pNativeData = OGR_F_GetFieldAsString(OSGeo.OGR.Feature.getCPtr(fe), index);
            if (pNativeData == IntPtr.Zero)
                return null;
            string s = Marshal.PtrToStringAnsi(pNativeData);
            return s;
        }

        /// <param name="fe"></param>
        /// <param name="index">索引</param>
        /// <param name="val">值</param>
        public static void setFieldString(Feature fe, int index, string val)
        {
            OGR_F_SetFieldString(OSGeo.OGR.Feature.getCPtr(fe), index, val);
        }

var field3 = f.GetFieldAsString(i);//这种直接获取出来的是gbk的乱码


    var field = getFieldAsStr(f, i);
    var bytes2 = System.Text.Encoding.Default.GetBytes(field);
    var sss = System.Text.Encoding.UTF8.GetString(bytes2);//同上。少一些字

用下面方法，实验可以
    //string fieldName = pFieldDefn.GetName();
    //int fieldIndex = pFeatureDefn.GetFieldIndex(fieldName);
    //IntPtr pIntPtr = OGR_F_GetFieldAsString(OSGeo.OGR.Feature.getCPtr(pFeature), fieldIndex);
    int byteCount = 0;
    IntPtr pIntPtr = OGR_F_GetFieldAsBinary(OSGeo.OGR.Feature.getCPtr(f), i, out byteCount);
    byte[] byteArray = new byte[byteCount];
    Marshal.Copy(pIntPtr, byteArray, 0, byteCount);
    string str = System.Text.Encoding.UTF8.GetString(byteArray);

    sb.Append(""" + key + "":"" + str + "",");