//如果实体属性名称和前端名称不一致，或者属性是一个自定义类型，需要继续访问其内部属性，使用点号分隔 93 if (propertyMap?.ContainsKey(rule.Field) == true) 94 { 95 names = propertyMap[rule.Field].Split('.', StringSplitOptions.RemoveEmptyEntries); 96 l = Expression.Property(parameter, names[0]); 97 foreach (var name in names.Skip(1)) 98 { 99 l = Expression.Property(l, name); 100 } 101 } 102 else 103 { 104 l = Expression.Property(parameter, rule.PascalField); 105 } 106 107 Expression r = null; //值表达式 108 Expression e; //返回bool的各种比较表达式 109 110 //属于和不属于比较是多值比较，需要调用Contains方法，而不是调用比较操作符 111 //为空和不为空的右值为常量null，不需要构造 112 var specialRuleOps = SpecialRuleOps; 113 114 var isNullable = false; 115 var pt = typeof(T); 116 if(names != null) 117 { 118 foreach(var name in names) 119 { 120 pt = pt.GetProperty(name).PropertyType; 121 } 122 } 123 else 124 { 125 pt = pt.GetProperty(rule.PascalField).PropertyType; 126 } 127 128 //如果属性类型是可空值类型，取出内部类型 129 if (pt.IsDerivedFrom(typeof(Nullable<>))) 130 { 131 isNullable = true; 132 pt = pt.GenericTypeArguments[0]; 133 } 134 135 //根据属性类型创建要比较的常量值表达式（也就是r） 136 if (!specialRuleOps.Contains(rule.Op)) 137 { 138 switch (pt) 139 { 140 case Type ct when ct == typeof(bool): 141 r = BuildConstantExpression(rule, bool.Parse); 142 break; 143 144 #region 文字 145 146 case Type ct when ct == typeof(char): 147 r = BuildConstantExpression(rule, str => str[0]); 148 break; 149 case Type ct when ct == typeof(string): 150 r = BuildConstantExpression(rule, str => str); 151 break; 152 153 #endregion 154 155 #region 有符号整数 156 157 case Type ct when ct == typeof(sbyte): 158 r = BuildConstantExpression(rule, sbyte.Parse); 159 break; 160 case Type ct when ct == typeof(short): 161 r = BuildConstantExpression(rule, short.Parse); 162 break; 163 case Type ct when ct == typeof(int): 164 r = BuildConstantExpression(rule, int.Parse); 165 break; 166 case Type ct when ct == typeof(long): 167 r = BuildConstantExpression(rule, long.Parse); 168 break; 169 170 #endregion 171 172 #region 无符号整数 173 174 case Type ct when ct == typeof(byte): 175 r = BuildConstantExpression(rule, byte.Parse); 176 break; 177 case Type ct when ct == typeof(ushort): 178 r = BuildConstantExpression(rule, ushort.Parse); 179 break; 180 case Type ct when ct == typeof(uint): 181 r = BuildConstantExpression(rule, uint.Parse); 182 break; 183 case Type ct when ct == typeof(ulong): 184 r = BuildConstantExpression(rule, ulong.Parse); 185 break; 186 187 #endregion 188 189 #region 小数 190 191 case Type ct when ct == typeof(float): 192 r = BuildConstantExpression(rule, float.Parse); 193 break; 194 case Type ct when ct == typeof(double): 195 r = BuildConstantExpression(rule, double.Parse); 196 break; 197 case Type ct when ct == typeof(decimal): 198 r = BuildConstantExpression(rule, decimal.Parse); 199 break; 200 201 #endregion 202 203 #region 其它常用类型 204 205 case Type ct when ct == typeof(DateTime): 206 r = BuildConstantExpression(rule, DateTime.Parse); 207 break; 208 case Type ct when ct == typeof(DateTimeOffset): 209 r = BuildConstantExpression(rule, DateTimeOffset.Parse); 210 break; 211 case Type ct when ct == typeof(Guid): 212 r = BuildConstantExpression(rule, Guid.Parse); 213 break; 214 case Type ct when ct.IsEnum: 215 r = Expression.Constant(rule.Data.ToEnumObject(ct)); 216 break; 217 218 #endregion 219 220 default: 221 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的数据表达式"); 222 } 223 } 224 225 if (r != null && pt.IsValueType && isNullable) 226 { 227 var gt = typeof(Nullable<>).MakeGenericType(pt); 228 r = Expression.Convert(r, gt); 229 } 230 231 switch (rule.Op) 232 { 233 case "eq": //等于 234 e = Expression.Equal(l, r); 235 break; 236 case "ne": //不等于 237 e = Expression.NotEqual(l, r); 238 break; 239 case "lt": //小于 240 e = Expression.LessThan(l, r); 241 break; 242 case "le": //小于等于 243 e = Expression.LessThanOrEqual(l, r); 244 break; 245 case "gt": //大于 246 e = Expression.GreaterThan(l, r); 247 break; 248 case "ge": //大于等于 249 e = Expression.GreaterThanOrEqual(l, r); 250 break; 251 case "bw": //开头是（字符串） 252 if (pt == typeof(string)) 253 { 254 e = Expression.Call(l, pt.GetMethod(nameof(string.StartsWith), new[] {typeof(string)}), r); 255 } 256 else 257 { 258 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的开始于表达式"); 259 } 260 261 break; 262 case "bn": //开头不是（字符串） 263 if (pt == typeof(string)) 264 { 265 e = Expression.Not(Expression.Call(l, pt.GetMethod(nameof(string.StartsWith), new[] {typeof(string)}), r)); 266 } 267 else 268 { 269 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的不开始于表达式"); 270 } 271 272 break; 273 case "ew": //结尾是（字符串） 274 if (pt == typeof(string)) 275 { 276 e = Expression.Call(l, pt.GetMethod(nameof(string.EndsWith), new[] {typeof(string)}), r); 277 } 278 else 279 { 280 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的结束于表达式"); 281 } 282 283 break; 284 case "en": //结尾不是（字符串） 285 if (pt == typeof(string)) 286 { 287 e = Expression.Not(Expression.Call(l, pt.GetMethod(nameof(string.EndsWith), new[] {typeof(string)}), r)); 288 } 289 else 290 { 291 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的不结束于表达式"); 292 } 293 294 break; 295 case "cn": //包含（字符串） 296 if (pt == typeof(string)) 297 { 298 e = Expression.Call(l, pt.GetMethod(nameof(string.Contains), new[] {typeof(string)}), r); 299 } 300 else 301 { 302 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的包含表达式"); 303 } 304 305 break; 306 case "nc": //不包含（字符串） 307 if (pt == typeof(string)) 308 { 309 e = Expression.Not(Expression.Call(l, pt.GetMethod(nameof(string.Contains), new[] {typeof(string)}), r)); 310 } 311 else 312 { 313 throw new InvalidOperationException($"不支持创建{pt.FullName}类型的包含表达式"); 314 } 315 316 break; 317 case "in": //属于（是候选值列表之一） 318 e = BuildContainsExpression(rule, l, pt); 319 break; 320 case "