[英]How to make use of memorystream instead of filestream
因此,我想做的就是從我的數據庫中讀取Select存儲過程,將數據保存在csv文件中,並確保用戶可以通過Web應用程序下載數據。 通過將文件臨時保存到程序文件夾中並使用文件流,可以得到請求的結果。 我現在想做的是跳過將文件保存到計算機上的部分,並將其臨時保存到RAM內存中。 據我了解,我必須利用內存流而不是文件流,但是我真的不明白我該怎么做。 據我了解,我不是使用文件而是將數據轉換為字節,而是將數據轉換為字節,然后在FileStreamResult中使用它。 我在這里正確嗎?
當我從過程中讀取並保存到csvfile時的方法:
public static String StoreApproved ()
{
string path1 = HttpRuntime.AppDomainAppPath + "Report.csv";
SqlConnection sqlConnection1 = new SqlConnection("CONNECTIONSTRING");
SqlCommand cmd = new SqlCommand();
SqlDataReader reader;
cmd.CommandText = "ExportApproved";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = sqlConnection1;
sqlConnection1.Open();
reader = cmd.ExecuteReader();
List<ModelStoreProcedureApproved> TestList = new List<ModelStoreProcedureApproved>();
ModelStoreProcedureApproved test ;
while (reader.Read())
{
test = new ModelStoreProcedureApproved();
// test.Id = int.Parse(reader["IdTimeTracker"].ToString());
test.Month = reader["Month"].ToString();
test.EmailUser = reader["Email"].ToString();
test.Project = reader["Name"].ToString();
test.Approved = reader["Description"].ToString();
test.Month = reader["Month"].ToString();
test.Year = reader["Year"].ToString();
TestList.Add(test);
}
File.Create(path1).Close();
var i = TestList.FirstOrDefault();
using (TextWriter fileReader = new StreamWriter(path1))
{
var csv = new CsvWriter(fileReader);
csv.Configuration.Encoding = Encoding.UTF8;
foreach (var value in TestList)
{
csv.WriteRecord(value);
}
fileReader.Close();
}
sqlConnection1.Close();
return path1;
}
控制器代碼:
public ActionResult ExportToCSV()
{
string path = Repositories.UserRepository.StoreApproved();
var fileStream = new FileStream(path,
FileMode.Open,
FileAccess.Read);
return new FileStreamResult(fileStream, "text/csv") { FileDownloadName = "export.csv" };
}
有人可以告訴我最好的方法是什么嗎? 我已閱讀其他使用BinaryFormatter進行序列化和反序列化的帖子
您可以這樣:
public static byte[] StoreApproved ()
{
string path1 = HttpRuntime.AppDomainAppPath + "Report.csv";
SqlConnection sqlConnection1 = new SqlConnection("CONNECTIONSTRING");
SqlCommand cmd = new SqlCommand();
SqlDataReader reader;
cmd.CommandText = "ExportApproved";
cmd.CommandType = CommandType.StoredProcedure;
cmd.Connection = sqlConnection1;
sqlConnection1.Open();
reader = cmd.ExecuteReader();
List<ModelStoreProcedureApproved> TestList = new List<ModelStoreProcedureApproved>();
ModelStoreProcedureApproved test ;
while (reader.Read())
{
test = new ModelStoreProcedureApproved();
// test.Id = int.Parse(reader["IdTimeTracker"].ToString());
test.Month = reader["Month"].ToString();
test.EmailUser = reader["Email"].ToString();
test.Project = reader["Name"].ToString();
test.Approved = reader["Description"].ToString();
test.Month = reader["Month"].ToString();
test.Year = reader["Year"].ToString();
TestList.Add(test);
}
var i = TestList.FirstOrDefault();
var mem = new MemoryStream();
using (TextWriter fileReader = new StreamWriter(mem))
{
var csv = new CsvWriter(fileReader);
csv.Configuration.Encoding = Encoding.UTF8;
foreach (var value in TestList)
{
csv.WriteRecord(value);
}
}
sqlConnection1.Close();
return mem.ToArray();
}
public ActionResult ExportToCSV()
{
byte[] bytes = Repositories.UserRepository.StoreApproved();
Stream stream = new MemoryStream(bytes);
return new FileStreamResult(stream, "text/csv") { FileDownloadName = "export.csv" };
}
由於您也使用Asp.Net MVC,因此建議您將關注點清晰地分開。 與其在同一方法中讀取和創建內存流,不如先讀取/獲取所需的數據集合,然后將數據從該方法中返回。 然后在action方法中,您可以根據需要用所需的格式(綁定到UI或返回文件等)裝飾它
盡管這不是您問題的直接答案,並且如果您要尋找的只是使用內存流,那么可以使用許多示例,例如此處顯示的示例以及您接受的答案等。
希望這對您有所幫助。
using (var ms = new MemoryStream())
{
using (var writer = new StreamWriter(ms))
using (var csv = new CsvWriter(writer))
{
csv.WriteRecords({A list here});
}
ms.ToArray() // here is your actual data in memory stream
}
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