DataReader-turn generic

Source: Internet
Author: User

The entity class must have a field type that is consistent with the database, or an error may occur.

  /// <summary>        ///DataReader-turn generic/// </summary>        /// <typeparam name= "T" >the entity class passed in</typeparam>        /// <param name= "objreader" >DataReader Object</param>        /// <returns></returns>        Private StaticIlist<t> readertolist<t> ( ThisIDataReader objreader) {            using(objreader) {List<T> list =NewList<t>(); //get the data type passed inType Modeltype =typeof(T); //traversing DataReader Objects                 while(Objreader.read ()) {//creates an instance of the specified type by using the constructor that matches the specified argument to the highestT model = activator.createinstance<t>();  for(inti =0; i < Objreader.fieldcount; i++)                    {                        //A value that determines whether the field value is empty or does not exist                        if(!Isnullordbnull (Objreader[i])) {                            //Match Field namePropertyInfo pi = modeltype.getproperty (Objreader.getname (i), BindingFlags.GetProperty | BindingFlags.Public | BindingFlags.Instance |bindingflags.ignorecase); if(Pi! =NULL)                            {                                //a field with the same name in the bound entity objectPi. SetValue (model, Checktype (objreader[i), Pi. PropertyType),NULL); }}} list.                ADD (model); }                returnlist; }        }        /// <summary>        ///Convert a nullable type (* otherwise an error)/// </summary>        /// <param name= "value" >the value of the DataReader field</param>        /// <param name= "Conversiontype" >the type of the field</param>        /// <returns></returns>        Private Static ObjectChecktype (Objectvalue, Type conversiontype) {            if(Conversiontype.isgenerictype && conversiontype.getgenerictypedefinition (). Equals (typeof(nullable<>)))            {                if(Value = =NULL)                    return NULL; System.ComponentModel.NullableConverter Nullableconverter=NewSystem.ComponentModel.NullableConverter (Conversiontype); Conversiontype=Nullableconverter.underlyingtype; }            returnConvert.changetype (value, conversiontype); }        /// <summary>        ///determines whether the specified object is a valid value/// </summary>        /// <param name= "obj" ></param>        /// <returns></returns>        Private Static BOOLIsnullordbnull (Objectobj) {            return(obj = =NULL|| (obj isDBNull))?true:false; }

DataReader-turn generic

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