[英]How to add new Row in DevExpress Gridview from DataTable on Button Click
[英]Gridview always add new row when click button?
我在单击按钮时编写了在gridview中创建新行的代码。 行数由文本框中的值创建。 例如:当我在文本框中输入值2时,当然会添加两行,但是当我再次单击按钮时,仍会添加第三行。 请在这里检查我的代码:
ASPX
<asp:TextBox ID="txtVisitor" runat="server"></asp:TextBox>
<asp:UpdatePanel ID="UpdatePanel1" runat="server">
<ContentTemplate>
<asp:GridView ID="Gridview1" runat="server" ShowFooter="true" AutoGenerateColumns="false">
<Columns>
<asp:BoundField DataField="RowNumber" HeaderText="Row Number" />
<asp:TemplateField HeaderText="Header 1">
<ItemTemplate>
<asp:TextBox ID="txtDate" runat="server"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Header 2">
<ItemTemplate>
<asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
</ItemTemplate>
</asp:TemplateField>
<asp:TemplateField HeaderText="Header 3">
<ItemTemplate>
<asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
</ItemTemplate>
<FooterStyle HorizontalAlign="Right" />
<FooterTemplate>
<asp:Button ID="ButtonAdd" runat="server" Text="Add New Row" OnClick="ButtonAdd_Click" />
</FooterTemplate>
</asp:TemplateField>
</Columns>
</asp:GridView>
</ContentTemplate>
</asp:UpdatePanel>
Code_Behind
protected void ButtonAdd_Click(object sender, EventArgs e)
{
int visitors = Convert.ToInt32(txtVisitor.Text);
AddNewRowToGrid(visitors);
}
private void SetInitialRow()
{
DataTable dt = new DataTable();
DataRow dr = null;
dt.Columns.Add(new DataColumn("RowNumber", typeof(string)));
dt.Columns.Add(new DataColumn("Column1", typeof(string)));
dt.Columns.Add(new DataColumn("Column2", typeof(string)));
dt.Columns.Add(new DataColumn("Column3", typeof(string)));
dr = dt.NewRow();
dr["RowNumber"] = 1;
dr["Column1"] = string.Empty;
dr["Column2"] = string.Empty;
dr["Column3"] = string.Empty;
dt.Rows.Add(dr);
//dr = dt.NewRow();
//Store the DataTable in ViewState
ViewState["CurrentTable"] = dt;
Gridview1.DataSource = dt;
Gridview1.DataBind();
}
private void AddNewRowToGrid(int visitors)
{
if (ViewState["CurrentTable"] != null)
{
DataTable dtCurrentTable = (DataTable)ViewState["CurrentTable"];
DataRow drCurrentRow;
if (dtCurrentTable.Rows.Count > 0)
{
int rowindex = 0;
for (int i = 1; i < visitors; i++)
{
//extract the TextBox values
TextBox box1 = (TextBox)Gridview1.Rows[rowindex].Cells[1].FindControl("txtDate");
TextBox box2 = (TextBox)Gridview1.Rows[rowindex].Cells[2].FindControl("TextBox2");
TextBox box3 = (TextBox)Gridview1.Rows[rowindex].Cells[3].FindControl("TextBox3");
drCurrentRow = dtCurrentTable.NewRow();
drCurrentRow["RowNumber"] = i + 1;
drCurrentRow["Column1"] = box1.Text;
drCurrentRow["Column2"] = box2.Text;
drCurrentRow["Column3"] = box3.Text;
dtCurrentTable.Rows.Add(drCurrentRow);
drCurrentRow = null;
rowindex++;
}
//add new row to DataTable
//Store the current data to ViewState
ViewState["CurrentTable"] = dtCurrentTable;
//Rebind the Grid with the current data
Gridview1.DataSource = dtCurrentTable;
Gridview1.DataBind();
}
}
else
{
Response.Write("ViewState is null");
}
}
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
SetInitialRow();
}
}
这是您的代码的问题1:
//extract the TextBox values
TextBox box1 = (TextBox)Gridview1.Rows[rowindex].Cells[1].FindControl("txtDate");
TextBox box2 = (TextBox)Gridview1.Rows[rowindex].Cells[2].FindControl("TextBox2");
TextBox box3 = (TextBox)Gridview1.Rows[rowindex].Cells[3].FindControl("TextBox3");
这种逻辑是有缺陷的,甚至不是必需的,因为绑定网格时,它将循环访问作为DataSource
提供的集合,并使用您在标记中定义的TemplateFields
创建每一行。
直到绑定到数据源(在本例中为DataTable
之前,这些行才真正添加到GridView中,如下所示:
Gridview1.DataSource = dt;
Gridview1.DataBind();
步骤1是从AddNewRowToGrid
方法中删除FindControl
行。
我什至不确定您要在代码中完成什么。
这是您的代码的问题1:
for (int i = dtCurrentTable.Rows.Count; i < visitors; i++)
{
//extract the TextBox values
TextBox box1 = (TextBox)Gridview1.Rows[rowindex].Cells[1].FindControl("txtDate");
TextBox box2 = (TextBox)Gridview1.Rows[rowindex].Cells[2].FindControl("TextBox2");
TextBox box3 = (TextBox)Gridview1.Rows[rowindex].Cells[3].FindControl("TextBox3");
drCurrentRow = dtCurrentTable.NewRow();
drCurrentRow["RowNumber"] = i + 1;
drCurrentRow["Column1"] = box1.Text;
drCurrentRow["Column2"] = box2.Text;
drCurrentRow["Column3"] = box3.Text;
dtCurrentTable.Rows.Add(drCurrentRow);
drCurrentRow = null;
rowindex++;
}
您将i设置为1将其替换为gridview的行数以从其开始
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