如何检查单元格是否为空 (Excel\VisualC#)

How to check if a cell is empty (Excel\VisualC#)

提问by Daniele

this might be an easy question for you and I saw a lot of topics about it, but none of them gave me the answer I need. My aim is to check line per line in the Sheet1in order to discover how many rows are, so i put a do\while that should stop once it reaches a blank cell

这对你来说可能是一个简单的问题，我看到了很多关于它的话题，但没有一个给我需要的答案。我的目标是检查每行的行Sheet1以发现有多少行，所以我放了一个 do\while，一旦它到达一个空白单元格就应该停止

Example:

例子：

row1 data
row2 data
row3 data
row4 data
row5 data

row6 data
row7 data

row1 数据
row2 数据
row3 数据
row4 数据
row5 数据

row6 数据
row7 数据

In this case I need only the first 5 rows, so the do\while check is intended to stop once it reaches the blank cell. This doesn't happens, because the check doesn't loop (it stops after completing a circle like it finds a blank cell even if it is filled with data).

在这种情况下，我只需要前 5 行，因此 do\while 检查旨在在到达空白单元格后停止。这不会发生，因为检查不会循环（它在完成一个圆圈后停止，就像它找到一个空白单元格，即使它填充了数据）。

string str;
int rCnt = 11; //the data I need is after the 10th row in excel
int cCnt = 1;
int valori = 1;

Excel.Application xlApp = new Excel.Application();
Excel.Workbook xlWorkbook = xlApp.Workbooks.Open(label4.Text, 0, false, 5, "", "", 
                                                 false, Excel.XlPlatform.xlWindows, 
                                                 "", true, false, 0, true, false, 
                                                 false);
Excel.Sheets xlsheet = xlWorkbook.Worksheets;
string sheet1 = "Sheet1";
Excel.Worksheet xlWorksheet = (Excel.Worksheet)xlsheet.get_Item(sheet1);
Excel.Range xlCell;   

do
{
    rCnt++;
    str = "A" + rCnt;
    xlCell = (Excel.Range)xlWorksheet.get_Range(str, str);
} while (xlCell.Value2 == null);

I tried changing Value2to Valueor Textand trying to set == "" instead of null.

我尝试更改Value2为ValueorText并尝试设置 == "" 而不是 null。

回答by matzone

If you want the loop stop when reach blank cell then .. Try to change

如果您希望在到达空白单元格时循环停止，则 .. 尝试更改

while (xlCell.Value2 == null);

with

和

while (! IsNull(xlCell.Value2));

回答by Grant Bagwell

The issue mainly comes from when you don't know what sort of data to expect. When I work with Excel reads I often do something similar to:

这个问题主要来自于您不知道期望什么样的数据。当我使用 Excel 读取时，我经常做类似的事情：

var _cell = range.Cells[1, 2].Value2;
if (_cell.GetType() != typeof(Double))

In your instance if you always are getting a string returned then you should be able to assume the cast:

在您的实例中，如果您总是返回一个字符串，那么您应该能够假设演员阵容：

string _str = (string)(range.Cells[str, str] as Excel.Range).Value2;

and then check that is not empty.

然后检查它不为空。

回答by thedrs

Simple way to check a cell is empty:

检查单元格为空的简单方法：

 if (sheet.Cells[4,3] == null || sheet.Cells[4,3].Value2 == null || sheet.Cells[4,3].Value2.ToString() == "")
   MessageBox.Show(“cell on row 4 col 3 is empty”);

回答by Joshua Ferdinand

do
{
    rCnt++;
    str = Sheet.Cells[rCnt, 5].Value;
} while (str != null);

回答by Jarus Rev

This is working for me:

这对我有用：

using Excel = Microsoft.Office.Interop.Excel;to read excelsheet:

通过Excel = Microsoft.Office.Interop.Excel;阅读excelsheet：

var excelApp = new Excel.Application();
Excel.Workbook excelWorkbook = excelApp.Workbooks.Open(path, 0, false, 5, "", "", false, XlPlatform.xlWindows, "", true, false, 0, true, false, false);

Excel.Worksheet excelWorksheet = (Excel.Worksheet)excelWorkbook.Sheets[2];

Excel.Range excelRange = excelWorksheet.UsedRange;
int rowCount = excelRange.Rows.Count;
int colCount = excelRange.Columns.Count;
string wwdEmpty = Convert.ToString(excelRange.Cells[5, 14].value2);
// this is working code with NULL Excell cell 

回答by Alatey

You can use the "Text" property of the selected cell. It can be converted to a string type via "as". The result string can already be checked as usual in C#, like not-empty

您可以使用所选单元格的“文本”属性。它可以通过“as”转换为字符串类型。结果字符串已经可以像往常一样在 C# 中检查，比如非空

string TempText = excelWorksheet.Cells[1, 1].Text as string;
if (!string.IsNullOrWhiteSpace(TempText)){
// actions
}