net中的GridView有多清晰?

I doing a web page in asp.net and in a module have select a Excel archive with FileUpLoad and click in a button import. Hitherto I'm fine. But in the moment than I want select other Excel archive and click in the button import, don't clear the GridView and show error. I attempt with this because I see in other questions similar to this.

我在asp.net中做一个网页，在一个模块中，我选择了一个Excel存档文件，并在一个按钮导入中进行上传。到目前为止我很好。但此时我想选择其他Excel归档文件并单击按钮导入，不清除GridView并显示错误。我尝试用这个，因为我看到了其他类似的问题。

With this I load the Grid

我用这个加载网格

Conn = string.Format(Conn, DireccionArchivo, MostrarHDR);
OleDbConnection ConnExcel = new OleDbConnection(Conn);
OleDbCommand CmdExcel = new OleDbCommand();
OleDbDataAdapter Oda = new OleDbDataAdapter();
DataTable Dt = new DataTable();
CmdExcel.Connection = ConnExcel;

ConnExcel.Open();
CmdExcel.CommandText = "SELECT * From ["Page1$"]";
Oda.SelectCommand = CmdExcel;
Oda.Fill(Dt);
ConnExcel.Close();

grdResultados.Caption =  Path.GetFileName(DireccionArchivo);
grdResultados.DataSource = Dt;
grdResultados.DataBind();

And with this I want to clear the GridView and last y called of new the method of load the GridView

有了这个，我想清除GridView最后y调用了新加载GridView的方法

DataTable ds = new DataTable();
ds = null;
grdResultados.DataSource = ds;
grdResultados.DataBind();

The error than show me is in the grdResultados.DataBind(); when called the second time.

显示的错误在grdresultado.net . databind()中;第二次叫的时候。

7 个解决方案

#1

Just use null value:

只使用null值:

grdResultados.DataSource = null;
grdResultados.DataBind();

#2

I resolved the problem, in the moment than clear the GridView with

我解决了这个问题，在那一刻用GridView清除了这个问题

DataTable ds = new DataTable();
ds = null;
grdResultados.DataSource = ds;
grdResultados.DataBind();

this clear the GridView but dont clear the names of columns, and this was the error, also have to clean the names of the columns. To remove the columns:

这样就清除了GridView，但不清除列的名称，这就是错误所在，还必须清除列的名称。删除列:

for (int i = 0; grdResultados.Columns.Count > i; )
{
    grdResultados.Columns.RemoveAt(i);
}

and in the method of load th GridView must be generate the columns automatically with this property:

在加载GridView的方法中，必须使用该属性自动生成列:

grdResultados.AutoGenerateColumns = true;

I leave this in case anyone else has the same problem

我把它留给别人，免得别人也有同样的问题。

#3

int gvHasRows = grdResultados.Rows.Count;
if (gvHasRows > 0)
{
    grdResultados.Columns.Clear();
    grdResultados.DataBind();
}

First check that there is data in the Gridview before trying to clear. Rows has no Clear function.

在尝试清除之前，首先检查Gridview中是否有数据。行没有明确的函数。

#4

try this

试试这个

grdResultados.DataSource = null;

或

grdResultados.Rows.Clear();

then rebind the gridview

然后重装gridview

#5

If you use a Session clear the session Example:

如果使用会话，请清除会话示例:

DataTable ds = new DataTable();
ds = null;
GV.DataSource = ds;
GV.DataBind();

for (int i = 0; GV.Columns.Count > i; )
{
    GV.Columns.RemoveAt(i);
}

ViewState["CurrentData"] = null;

#6

Make an empty data table with just your column names and re bind

创建一个只有列名的空数据表并重新绑定

#7

You can simply do this:

你可以这样做:

GridView1.SelectedIndex = -1;

#1