Merge pull request #35 from ODotNet/standard2.0

fix bugs:issue32

samples/Npoi.Samples.CreateNewSpreadsheet/Issue32.cs

@@ -0,0 +1,40 @@
+
+using NPOI.HSSF.UserModel;
+using NPOI.SS.UserModel;
+using NPOI.XSSF.UserModel;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Npoi.Samples.CreateNewSpreadsheet
+{
+    public class Issue32
+    {
+        public static void Run()
+        {
+            new Issue32().ReadExcel();
+        }
+
+        public void ReadExcel()
+        {
+            //using (var file = new FileStream(@"D:\GitStorage\Npoi.Core\samples\Npoi.Samples.CreateNewSpreadsheet\template.xlsx", FileMode.Open, FileAccess.Read))
+            //{
+            //    var excel = new XSSFWorkbook(file);
+            //    var cell = excel.GetSheetAt(0).GetRow(0).GetCell(0);
+            //    Console.WriteLine(cell.NumericCellValue);
+            //}
+
+            //using (var file = new FileStream(@"D:\GitStorage\Npoi.Core\samples\Npoi.Samples.CreateNewSpreadsheet\template.xls", FileMode.Open, FileAccess.Read))
+            //{
+            //    var excel = new HSSFWorkbook(file);
+            //    var cell = excel.GetSheetAt(0).GetRow(1).GetCell(2);
+            //    Console.WriteLine(cell.NumericCellValue);
+            //}
+
+            string filePath = $@"D:\GitStorage\Npoi.Core\samples\Npoi.Samples.CreateNewSpreadsheet\template.xlsx";
+            IWorkbook workbook = WorkbookFactory.Create(filePath);            
+            workbook.Close();
+        }
+    }
+}

samples/Npoi.Samples.CreateNewSpreadsheet/Issue33.cs

@@ -0,0 +1,39 @@
+using NPOI.XSSF.UserModel;
+using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Text;
+
+namespace Npoi.Samples.CreateNewSpreadsheet
+{
+    class Issue33
+    {
+        public static void Run()
+        {
+            var issue33 = new Issue33();
+            issue33.WriteExcel();
+        }
+
+        public void WriteExcel()
+        {
+            string outputFileName = $@"D:\GitStorage\Npoi.Core\samples\Npoi.Samples.CreateNewSpreadsheet\template-{DateTime.Now.Ticks.ToString()}.xlsx";
+            using (var templateStream =new FileStream(@"D:\GitStorage\Npoi.Core\samples\Npoi.Samples.CreateNewSpreadsheet\template.xlsx", FileMode.Open, FileAccess.Read))
+            {
+                var excel = new XSSFWorkbook(templateStream);
+                var cell = excel.GetSheetAt(0).GetRow(2).GetCell(2);
+                cell.SetCellValue("Issue 33");
+
+                using (var outputStream = new FileStream(outputFileName, FileMode.Create, FileAccess.Write))
+                {
+                    excel.Write(outputStream);
+                }
+            }
+            using (var outputStream = File.OpenRead(outputFileName))
+            {
+                var excel = new XSSFWorkbook(outputStream);
+                var cell = excel.GetSheetAt(0).GetRow(2).GetCell(2);
+                Console.WriteLine(cell.ToString()); //here can console Issue 33
+            }
+        }
+    }
+}

samples/Npoi.Samples.CreateNewSpreadsheet/Program.cs

@@ -16,7 +16,9 @@ namespace Npoi.Samples.CreateNewSpreadsheet
             //ExportExcel();
             //ExportExcelHSSF();
             //ExportWord();
-            ImportExcelHSSF();
+            //ImportExcelHSSF();
+            Issue32.Run();
+            Console.Read();
         }
 
         private static void ImportExcelHSSF() {

src/NPOI.OpenXml4Net/OPC/ZipPackage.cs

@@ -343,7 +343,9 @@ namespace NPOI.OpenXml4Net.OPC
                     {
                         // Either the save operation succeed or not, we delete the
                         // temporary file
-                        File.Delete(tempfilePath);
+                        //Fixbug:https://github.com/dotnetcore/NPOI/issues/32
+                        //File.Delete(tempfilePath);
+                        fi.Delete();
                         
                             logger
                                     .Log(POILogger.WARN, "The temporary file: '"