c# - CSV Helper not writing to file -
i've been stuck trying csv helper write file. when run action downloads file proper name , else, never writes it.
public async task<stream> getdownloadstreamasync(int id) { var memorystream = new memorystream(); var streamwriter = new streamwriter(memorystream); var streamreader = new streamreader(memorystream); var csvhelper = new csvhelper.csvwriter(streamwriter); csvhelper.writerecord(new eventregistrant { firstname = "max" }); await memorystream.flushasync(); memorystream.position = 0; return memorystream; }
the action:
public async task<actionresult> downloadregistrantscsv(int id) { var @event = await _service.getasync(id, true); if (@event == null) return httpnotfound(); var stream = await _service.getdownloadstreamasync(id); return file(stream, "application/txt", "test" + ".csv"); } i've tried using documentation csv helper , can't write. here's i've got that...
// copyright 2009-2015 josh close , contributors // file part of csvhelper , dual licensed under ms-pl , apache 2.0. // see license.txt details or visit http://www.opensource.org/licenses/ms-pl.html ms-pl , http://opensource.org/licenses/apache-2.0 apache 2.0. // http://csvhelper.com using system; using system.collections; using system.collections.generic; using system.componentmodel; using system.globalization; using system.io; using system.web.script.serialization; using csvhelper.configuration; using csvhelper.typeconversion; namespace csvhelper.example { class program { private const string columnseparator = ":"; static void main(string[] args) { //readrawfieldsbyindex(); //readrawfieldsbyname(); //readfieldsbyindex(); //readrecordsnoattributes(); //readrecordswithattributes(); //readallrecords(); //writerawfields(); //writefields(); writerecordsnoattributes(); //writerecordswithattributes(); writeallrecords(); console.readkey(); } public static void readrawfieldsbyindex() { console.writeline("raw fields index:"); using (var reader = new csvreader(new streamreader(getdatastream(true, true)))) { while (reader.read()) { console.write(reader.getfield(0) + columnseparator); console.write(reader.getfield(1) + columnseparator); console.write(reader.getfield(2) + columnseparator); console.writeline(reader.getfield(3)); } } console.writeline(); } public static void readrawfieldsbyname() { console.writeline("raw fields name:"); using (var reader = new csvreader(new streamreader(getdatastream(true, true)))) { while (reader.read()) { console.write(reader.getfield("string column") + columnseparator); console.write(reader.getfield("int column") + columnseparator); console.write(reader.getfield("guid column") + columnseparator); console.write(reader.getfield("does not exist column") + columnseparator); console.writeline(reader.getfield("custom type column")); } } console.writeline(); } public static void readfieldsbyindex() { console.writeline("fields index:"); var customtypetypeconverter = new customtypetypeconverter(); using (var reader = new csvreader(new streamreader(getdatastream(true, true)))) { while (reader.read()) { console.write(reader.getfield<string>(0) + columnseparator); console.write(reader.getfield<int>("int column") + columnseparator); console.write(reader.getfield<guid>(2) + columnseparator); console.writeline(reader.getfield<customtype>(3, customtypetypeconverter)); } } console.writeline(); } public static void readrecordsnoattributes() { console.writeline("records no attributes:"); using (var reader = new csvreader(new streamreader(getdatastream(true, false)))) { while (reader.read()) { console.writeline(reader.getrecord<customobject>()); } } console.writeline(); } public static void readrecordswithattributes() { console.writeline("records attributes:"); using (var reader = new csvreader(new streamreader(getdatastream(true, true)))) { reader.configuration.registerclassmap<customobjectwithmappingmap>(); while (reader.read()) { console.writeline(reader.getrecord<customobjectwithmapping>()); } } console.writeline(); } public static void readallrecords() { console.writeline("all records:"); using (var reader = new csvreader(new streamreader(getdatastream(true, false)))) { var records = reader.getrecords<customobject>(); foreach (var record in records) { console.writeline(record); } } console.writeline(); } public static void writerawfields() { console.writeline("write raw fields"); using (var memorystream = new memorystream()) using (var streamwriter = new streamwriter(memorystream)) using (var streamreader = new streamreader(memorystream)) using (var writer = new csvwriter(streamwriter)) { writer.writefield("string column"); writer.writefield("int column"); writer.writefield("guid column"); writer.writefield("custom type column"); writer.nextrecord(); writer.writefield("one"); writer.writefield((1).tostring()); writer.writefield(guid.newguid().tostring()); writer.writefield((new customtype { first = 1, second = 2, third = 3 }).tostring()); writer.nextrecord(); memorystream.position = 0; console.writeline(streamreader.readtoend()); } console.writeline(); } public static void writefields() { console.writeline("write fields"); using (var memorystream = new memorystream()) using (var streamwriter = new streamwriter(memorystream)) using (var streamreader = new streamreader(memorystream)) using (var writer = new csvwriter(streamwriter)) { writer.writefield("string column"); writer.writefield("int column"); writer.writefield("guid column"); writer.writefield("custom type column"); writer.nextrecord(); writer.writefield("one"); writer.writefield(1); writer.writefield(guid.newguid()); writer.writefield(new customtype { first = 1, second = 2, third = 3 }); writer.nextrecord(); memorystream.position = 0; console.writeline(streamreader.readtoend()); } console.writeline(); } public static void writerecordsnoattributes() { console.writeline("write records no attributes:"); var records = new list<customobject> { new customobject { customtypecolumn = new customtype { first = 1, second = 2, third = 3, }, guidcolumn = guid.newguid(), intcolumn = 1, stringcolumn = "one", }, new customobject { customtypecolumn = new customtype { first = 4, second = 5, third = 6, }, guidcolumn = guid.newguid(), intcolumn = 2, stringcolumn = "two", }, }; using (var memorystream = new memorystream()) using (var streamwriter = new streamwriter(memorystream)) using (var streamreader = new streamreader(memorystream)) using (var writer = new csvwriter(streamwriter)) { foreach (var record in records) { writer.writerecord(record); } memorystream.position = 0; console.writeline(streamreader.readtoend()); } console.writeline(); } public static void writerecordswithattributes() { console.writeline("write records attributes:"); var records = new list<customobjectwithmapping> { new customobjectwithmapping { customtypecolumn = new customtype { first = 1, second = 2, third = 3, }, guidcolumn = guid.newguid(), intcolumn = 1, stringcolumn = "one", }, new customobjectwithmapping { customtypecolumn = new customtype { first = 4, second = 5, third = 6, }, guidcolumn = guid.newguid(), intcolumn = 2, stringcolumn = "two", }, }; using (var memorystream = new memorystream()) using (var streamwriter = new streamwriter(memorystream)) using (var streamreader = new streamreader(memorystream)) using (var writer = new csvwriter(streamwriter)) { foreach (var record in records) { writer.writerecord(record); } memorystream.position = 0; console.writeline(streamreader.readtoend()); } console.writeline(); } public static void writeallrecords() { console.writeline("write records attributes:"); var records = new list<customobjectwithmapping> { new customobjectwithmapping { customtypecolumn = new customtype { first = 1, second = 2, third = 3, }, guidcolumn = guid.newguid(), intcolumn = 1, stringcolumn = "one", }, new customobjectwithmapping { customtypecolumn = new customtype { first = 4, second = 5, third = 6, }, guidcolumn = guid.newguid(), intcolumn = 2, stringcolumn = "two", }, }; using (var memorystream = new memorystream()) using (var streamwriter = new streamwriter(memorystream)) using (var streamreader = new streamreader(memorystream)) using (var writer = new csvwriter(streamwriter)) { writer.configuration.registerclassmap<customobjectwithmappingmap>(); writer.writerecords(records ienumerable); memorystream.position = 0; console.writeline(streamreader.readtoend()); } console.writeline(); } public static memorystream getdatastream(bool hasheader, bool hasspacesinheadernames) { var stream = new memorystream(); var writer = new streamwriter(stream); if (hasheader) { var header = hasspacesinheadernames ? "string column,int column,guid column,custom type column" : "stringcolumn,intcolumn,guidcolumn,customtypecolumn"; writer.writeline(header); } writer.writeline("one,1,{0},1|2|3", guid.newguid()); writer.writeline("two,2,{0},4|5|6", guid.newguid()); writer.writeline("\"this, has comma\",2,{0},7|8|9", guid.newguid()); writer.writeline("\"this has \"\"'s\",4,{0},10|11|12", guid.newguid()); writer.flush(); stream.position = 0; return stream; } public class customtype { public int first { get; set; } public int second { get; set; } public int third { get; set; } public override string tostring() { var serializer = new javascriptserializer(); return serializer.serialize(this); } } public class customtypetypeconverter : itypeconverter { public string converttostring(typeconverteroptions options, object value) { var obj = (customtype)value; return string.format("{0}|{1}|{2}", obj.first, obj.second, obj.third); } public object convertfromstring(typeconverteroptions options, string text) { var values = ((string)text).split('|'); var obj = new customtype { first = int.parse(values[0]), second = int.parse(values[1]), third = int.parse(values[2]), }; return obj; } public bool canconvertfrom(type type) { throw new notimplementedexception(); } public bool canconvertto(type type) { throw new notimplementedexception(); } } public class customobject { public customtype customtypecolumn { get; set; } public guid guidcolumn { get; set; } public int intcolumn { get; set; } public string stringcolumn { get; set; } public override string tostring() { var serializer = new javascriptserializer(); return serializer.serialize(this); } } public class customobjectwithmapping { public customtype customtypecolumn { get; set; } public guid guidcolumn { get; set; } public int intcolumn { get; set; } public string stringcolumn { get; set; } public string ignoredcolumn { get; set; } //public override string tostring() //{ // var serializer = new javascriptserializer(); // return serializer.serialize(this); //} } public sealed class customobjectwithmappingmap : csvclassmap<customobjectwithmapping> { public customobjectwithmappingmap() { map(m => m.customtypecolumn).name("custom type column").index(3).typeconverter<customtypetypeconverter>(); map(m => m.guidcolumn).name("guid column").index(2); map(m => m.intcolumn).name("int column").index(1); map(m => m.stringcolumn).name("string column").index(0); } } } } can point me might missing or doing wrong?
if have datatable can convert comma separated value list of strings this...
/// <summary> /// creates comma separated value string datatable. /// </summary> public static string tocsv(datatable table) { stringbuilder csv = new stringbuilder(); for(int = 0; < table.columns.count ;i++) // process column headers { if (i > 0) csv.append(","); csv.append(_formattocsvfield(table.columns[i].columnname)); } if (table.columns.count > 0) csv.append("\r\n"); (int = 0; < table.rows.count; i++) // process row data { (int j = 0; j < table.columns.count; j++) // process each field in data row. { if (j > 0) csv.append(","); csv.append(_formattocsvfield(table.rows[i][j].tostring())); } csv.append("\r\n"); } return csv.tostring(); } private static string _formattocsvfield(string unformattedfield) { return "\"" + unformattedfield.replace("\"", "\"\"") + "\""; } or if didn't have datatable; take take created comma separated value (csv) list of string "row1 column 1, row1 column2, row1 column3, \r\n, row2, colum1... etc..."
and save csv file, this...
//your csv string string whattowrite = "row1 column 1, row1 column2, row1 column3, \r\n"; //convert csv string byte[] byte[] putwhattowriteintobytes = encoding.getencoding("iso-8859-1").getbytes(whattowrite); //write byte[] csv readable excel string filename = "whatyouwanttocallyourfile" + ".csv"; response.contenttype = "application/vnd.openxmlformats-officedocument.spreadsheetml.sheet"; response.addheader("content-disposition", filename.tostring()); response.clear(); response.binarywrite(putwhattowriteintobytes); response.end(); its hard follow code. trying write csv...get that; check if good. write file. determine if writing empty string, or if writing losing string
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