【发布时间】：2014-06-26 20:48:51
【问题描述】：
我能够根据 DropDownlist 选择的输入生成动态 Web 控件。我需要实现一个按钮单击事件，该事件应该遍历来自这些动态 Web 控件的所有输入并在 JQGrid 表中显示结果。
要求：如何使用 SavedViewState() 和 LoadViewState() 保留来自这些动态 Web 控件的所有输入文本。我是动态 Web 控件和视图状态的新手。需要帮助
我已经给出了完整的示例代码。
我的 C# 代码：
private void BindDropDownLists()
{
column_list_for_filter.ConnectionString = connection;
string item = "--Select--";
column_list_for_filter.SelectCommand = "SELECT DATA_TYPE + '_' + convert(varchar(10), ROW_NUMBER() OVER(ORDER BY DATA_TYPE))as DATA_TYPE, COLUMN_NAME FROM INFORMATION_SCHEMA.COLUMNS WHERE (TABLE_NAME = 'RESULT' AND COLUMN_NAME IN ('Column1','Column2','Column3','Column4'))";
DropDownList5.DataTextField = "COLUMN_NAME";
DropDownList5.DataValueField = "DATA_TYPE";
DropDownList5.DataBind();
DropDownList5.Items.Insert(0, item);
}
protected void createdynamiccontrols_decimal()
{
int i = DropDownList5.SelectedIndex;
++i;
TableRow row = new TableRow();
row.ID = "TableRow_";
TableCell cell1 = new TableCell();
cell1.ID = "TableCell_";
DropDownList Range_DDL_Decimal = new DropDownList();
Range_DDL_Decimal.ID = "RandeDDL_Decimal" + i.ToString();
Range_DDL_Decimal.Items.Insert(0, new ListItem("--Select--", "--Select--"));
Range_DDL_Decimal.Items.Insert(1, new ListItem("Equal", "Equal"));
Range_DDL_Decimal.Items.Insert(2, new ListItem("NotEqual", "NotEqual"));
Range_DDL_Decimal.Items.Insert(3, new ListItem("greater than", "greater than"));
Range_DDL_Decimal.Items.Insert(4, new ListItem("lesser than", "lesser than"));
Range_DDL_Decimal.Items.Insert(5, new ListItem("greater than or equal to", "greater than or equal to"));
Range_DDL_Decimal.Items.Insert(6, new ListItem("lesser than or equal to", "lesser than or equal to"));
Range_DDL_Decimal.Items.Insert(7, new ListItem("Contains", "Contains"));
Range_DDL_Decimal.Items.Insert(8, new ListItem("Is Null", "Is Null"));
Range_DDL_Decimal.Items.Insert(9, new ListItem("Is Not Null", "Is Not Null"));
Range_DDL_Decimal.Items.Insert(10, new ListItem("Between", "Between"));
Range_DDL_Decimal.AutoPostBack = true;
Range_DDL_Decimal.SelectedIndexChanged += new System.EventHandler(Range_DDL_Decimal_SelectedIndexChanged);
cell1.Controls.Add(Range_DDL_Decimal);
//// Add the TableCell to the TableRow
row.Cells.Add(cell1);
dynamic_filter_table.Rows.Add(row);
dynamic_filter_table.EnableViewState = true;
ViewState["dynamic_filter_table"] = true;
}
protected void Range_DDL_Decimal_SelectedIndexChanged(object sender, EventArgs e)
{
int j = DropDownList5.SelectedIndex;
++j;
TableCell cell2 = new TableCell();
TextBox tb1 = new TextBox();
TextBox tb2 = new TextBox();
Label lbl1 = new Label();
Label lbl2 = new Label();
// Set a unique ID for each TextBox added
tb1.ID = "lowerbound_" + j.ToString();
tb2.ID = "upperbound_" + j.ToString();
lbl1.Text = "LowerBound:";
lbl1.Font.Size = FontUnit.Point(10);
lbl1.Font.Bold = true;
lbl1.Font.Name = "Arial";
lbl2.Text = "UpperBound:";
lbl2.Font.Size = FontUnit.Point(10);
lbl2.Font.Bold = true;
lbl2.Font.Name = "Arial";
cell2.Controls.Add(lbl1);
cell2.Controls.Add(tb1);
cell2.Controls.Add(lbl2);
cell2.Controls.Add(tb2);
TableRow rowtwo = dynamic_filter_table.FindControl("TableRow_") as TableRow;
rowtwo.Cells.Add(cell2);
dynamic_filter_table.Rows.Add(rowtwo);
dynamic_filter_table.EnableViewState = true;
ViewState["dynamic_filter_table"] = true;
}
protected override object SaveViewState()
{
/***1. Retain DDL 1 selected text
2. Retain DDL 2 selected text DDL2 generated by DDL 1
3. Retain Tb1.text and tb2.text generated by DDL2 ***/
//How to Proceed
}
protected override void LoadViewState(object savedState)
{
//How to Proceed
}
protected void Button1_Click(object sender, EventArgs e)
{
int j = DropDownList5.SelectedIndex;
++j;
Panel6.Visible = true;
JQGrid9.Visible = true;
//Find Control not working
TextBox lowerboundd = dynamic_filter_table.FindControl("lowerbound_" + j.ToString()) as TextBox;
TextBox upperbound = dynamic_filter_table.FindControl("upperbound_" + j.ToString()) as TextBox;
con.Open();
// **How to pass values to this query from savedstate**
SqlDataAdapter da = new SqlDataAdapter("SELECT * FROM RESULT WHERE " + DropDownList5.Text + DDL2.Text + " >= " + lowerboundd.Text + " AND " + DropDownList5.Text + " <= " + upperbound.Text, con);
DataSet ds = new DataSet();
da.Fill(ds);
con.Close();
Session["DataforSearch"] = ds.Tables[0];
}
protected void Page_Load(object sender, EventArgs e)
{
Panel6.Visible = false;
JQGrid9.Visible = false;
if (Session["DataforSearch"] != null)
{
Panel6.Visible = true;
JQGrid9.Visible = true;
JQGrid9.DataSource = Session["DataforSearch"] as string;
}
if (!IsPostBack)
{
BindDropDownLists();
}
else
{
if (!String.IsNullOrEmpty(DropDownList5.SelectedValue))
{
if (DropDownList5.SelectedValue.Contains("decimal"))
{
createdynamiccontrols_decimal();
}
else if (DropDownList5.SelectedValue.Contains("varchar"))
{
createdynamiccontrols_varchar();
}
else if (DropDownList5.SelectedValue.Contains("datetime"))
{
createdynamiccontrols_datetime();
}
else if (DropDownList5.SelectedValue.Contains("int"))
{
createdynamiccontrols_int();
}
}
}
}
protected void Page_PreInit(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindDropDownLists();
}
else
{
if (!String.IsNullOrEmpty(DropDownList5.SelectedValue))
{
if (DropDownList5.SelectedValue.Contains("decimal"))
{
createdynamiccontrols_decimal();
}
else if (DropDownList5.SelectedValue.Contains("varchar"))
{
createdynamiccontrols_varchar();
}
else if (DropDownList5.SelectedValue.Contains("datetime"))
{
createdynamiccontrols_datetime();
}
else if (DropDownList5.SelectedValue.Contains("int"))
{
createdynamiccontrols_int();
}
}
}
【问题讨论】：
-
您可以保留/保存第一次创建它们的步骤/选定值，然后您需要在 Page Init 上重新创建它们。
-
@Aristos 你能帮我在上面添加几行代码吗？
-
found 一种方法，这里还有其他方法
标签： c# asp.net dynamic viewstate web-controls