好的，下面我粘贴了工作示例。
需要注意的事项：
Message=Failed to load viewstate. The control tree into which viewstate is being loaded must match the control tree that was used to save viewstate during the previous request. For example, when adding controls dynamically, the controls added during a post-back must match the type and position of the controls added during the initial request.
Source=System.Web
ErrorCode=-2147467259
在动态控件上设置此属性
EnableViewState = false
此示例的数据如下所示
品牌引擎色彩成本
大众，1.2，黑色，72 000
大众，1.2，白色，70 000
大众，1.6 TDI，红色，79 500
大众，1.6 TDI，白色，78 800
福特，1.6，黑色，57 600
福特，1.6，格林，57 100
福特，2.0 TDCi，黑色，87 300
福特，2.0 TDCi，白色，86 600
基本上是这样工作的：
- 选择汽车品牌并选择按钮（按钮是我们生成g控件的标准）
当然，您也可以使用下拉列表等进行逻辑处理。
- 在第二个屏幕上，根据您的选择，您有一个或两个下拉菜单
- 如果您有两个下拉菜单，第二个取决于第一个下拉菜单的选择，因此您有依赖和回发的示例
页面代码：
<form id="form1" runat="server">
<div>
<asp:MultiView ID="mvPanels" runat="server">
<asp:View ID="vPanel1" runat="server">
<table>
<tbody>
<tr>
<td>Pick car</td>
<td><asp:DropDownList ID="ddlBrand" runat="server" /></td>
<td><asp:Button ID="btnPanel1Next" Text="Next" runat="server"
onclick="btnPanel1Next_Click" /></td>
<td><asp:Button ID="btnPanel1NextEngineOnly" Text="Next (pick engine only)" runat="server"
onclick="btnPanel1NextEngineOnly_Click" /></td>
</tr>
</tbody>
</table>
</asp:View>
<asp:View ID="vPanel2" runat="server">
<%--<table>
<tbody>
<tr>
<td>Pick engine</td>
<td><asp:DropDownList ID="ddlEngine" AutoPostBack="true" runat="server"
onselectedindexchanged="ddlEngine_SelectedIndexChanged" /></td>
<td><asp:DropDownList ID="ddlColor" AutoPostBack="true" runat="server"
onselectedindexchanged="ddlColor_SelectedIndexChanged" /></td>
<td><asp:Button ID="btnPanel2Prev" Text="Prev" runat="server"
onclick="btnPanel2Prev_Click" /><asp:Button ID="btnPanel2Next" Text="Next"
runat="server" Enabled="False" onclick="btnPanel2Next_Click" /></td>
</tr>
</tbody>
</table>--%>
</asp:View>
<asp:View ID="vPanel3" runat="server">
<table>
<tbody>
<tr>
<td><asp:Label ID="lblResult" runat="server" /></td>
<td><asp:Button ID="btnPanel3Prev" Text="Prev" runat="server"
onclick="btnPanel3Prev_Click" /><asp:Button ID="btnPanel3Finish"
Text="Confirm" runat="server" onclick="btnPanel3Finish_Click" /></td>
</tr>
</tbody>
</table>
</asp:View>
</asp:MultiView>
</div>
</form>
后面的代码：
public partial class Default : System.Web.UI.Page
{
public class CarConfiguration
{
public string Brand { get; set; }
public string Engine { get; set; }
public PaintColor Paint { get; set; }
public string Cost { get; set; }
}
[Serializable]
public class CarConfigurationFilter
{
public string Brand { get; set; }
public string Engine { get; set; }
public PaintColor? Paint { get; set; }
public bool EngineOnly { get; set; }
}
public enum PaintColor
{
Black,
Red,
White,
Green,
}
public List<CarConfiguration> availableCars = new List<CarConfiguration>
{
new CarConfiguration{
Brand = "VW",
Engine = "1.2",
Paint = PaintColor.Black,
Cost = "72 000",
},
new CarConfiguration{
Brand = "VW",
Engine = "1.2",
Paint = PaintColor.White,
Cost = "70 000",
},
new CarConfiguration{
Brand = "VW",
Engine = "1.6 TDI",
Paint = PaintColor.Red,
Cost = "79 500"
},
new CarConfiguration{
Brand = "VW",
Engine = "1.6 TDI",
Paint = PaintColor.White,
Cost = "78 800",
},
new CarConfiguration{
Brand = "Ford",
Engine = "1.6",
Paint = PaintColor.Black,
Cost = "57 600"
},
new CarConfiguration{
Brand = "Ford",
Engine = "1.6",
Paint = PaintColor.Green,
Cost = "57 100"
},
new CarConfiguration{
Brand = "Ford",
Engine = "2.0 TDCi",
Paint = PaintColor.Black,
Cost = "87 300"
},
new CarConfiguration{
Brand = "Ford",
Engine = "2.0 TDCi",
Paint = PaintColor.White,
Cost = "86 600"
},
};
CarConfigurationFilter filter
{
get { return (CarConfigurationFilter)ViewState["Filter"]; }
set { ViewState["Filter"] = value; }
}
//If you have multiview in control you need to create this in event before event PageLoad like LoadViewState, LoadControlState, LoadControlState
protected override void OnPreLoad(EventArgs e)
{
if (IsPostBack && mvPanels.ActiveViewIndex == 1)
{
CreateControlsOnPanel2(true, !filter.EngineOnly);
}
base.OnPreLoad(e);
}
protected override void OnLoad(EventArgs e)
{
if (!IsPostBack)
{
ddlBrand.DataSource = availableCars.Select(x => x.Brand).Distinct();
ddlBrand.DataBind();
filter = new CarConfigurationFilter();
mvPanels.ActiveViewIndex = 0;
}
base.OnLoad(e);
}
protected void btnPanel1Next_Click(object sender, EventArgs e)
{
filter.Brand = ddlBrand.SelectedValue;
filter.EngineOnly = false;
CreateControlsOnPanel2(true, true);
mvPanels.ActiveViewIndex++;
}
protected void btnPanel1NextEngineOnly_Click(object sender, EventArgs e)
{
filter.Brand = ddlBrand.SelectedValue;
filter.EngineOnly = true;
CreateControlsOnPanel2(true, false);
mvPanels.ActiveViewIndex++;
}
void CreateControlsOnPanel2(bool enginePickerEnabled, bool colorPickerEnabled)
{
var btnPanel2Prev = new Button();
btnPanel2Prev.ID = "btnPanel1Prev";
btnPanel2Prev.EnableViewState = false;
btnPanel2Prev.Text = "Prev";
btnPanel2Prev.Click += btnPanel2Prev_Click;
var btnPanel2Next = new Button();
btnPanel2Next.ID="btnPanel2Next";
btnPanel2Next.Text = "Next";
btnPanel2Next.EnableViewState = false;
btnPanel2Next.Enabled = false;
btnPanel2Next.Click += btnPanel2Next_Click;
if (enginePickerEnabled)
{
var ddlEngine = new DropDownList();
ddlEngine.ID = "ddlEngine";
ddlEngine.AutoPostBack = true;
ddlEngine.EnableViewState = false;
var engines = availableCars.Where(x => x.Brand == filter.Brand).Select(found => found.Engine).Distinct().ToList();
engines.Insert(0, String.Empty);
ddlEngine.DataSource = engines;
ddlEngine.DataBind();
if (!String.IsNullOrEmpty(filter.Engine))
{
ddlEngine.SelectedValue = filter.Engine;
if (!colorPickerEnabled)
btnPanel2Next.Enabled = true;
}
else
ddlEngine.SelectedIndex = 0;
ddlEngine.SelectedIndexChanged += ddlEngine_SelectedIndexChanged;
vPanel2.Controls.Add(ddlEngine);
}
//remember to add ID to all dynamic controls or there might be an error on postback
if (colorPickerEnabled)
{
var ddlColor = new DropDownList();
ddlColor.ID = "ddlColor";
ddlColor.AutoPostBack = true;
ddlColor.EnableViewState = false;
ddlColor.SelectedIndexChanged += ddlColor_SelectedIndexChanged;
vPanel2.Controls.Add(ddlColor);
if (!String.IsNullOrEmpty(filter.Engine))
{
var colors = availableCars.Where(x => x.Brand == filter.Brand && x.Engine == filter.Engine).Select(found => found.Paint.ToString()).Distinct().ToList();
colors.Insert(0, String.Empty);
ddlColor.DataSource = colors;
if (filter.Paint.HasValue)
{
ddlColor.SelectedValue = filter.Paint.Value.ToString();
btnPanel2Next.Enabled = true;
}
}
else
{
ddlColor.DataSource = null;
ddlColor.SelectedIndex = 0;
}
ddlColor.DataBind();
}
vPanel2.Controls.Add(btnPanel2Prev);
vPanel2.Controls.Add(btnPanel2Next);
}
protected void ddlEngine_SelectedIndexChanged(object sender, EventArgs e)
{
var ddlEngine = sender as DropDownList;
var btnPanel2Next = (Button)vPanel2.FindControl("btnPanel2Next");
if (!String.IsNullOrEmpty(ddlEngine.SelectedValue))
{
filter.Engine = ddlEngine.SelectedValue;
var colors = availableCars.Where(x => x.Brand == filter.Brand && x.Engine == filter.Engine).Select(found => found.Paint.ToString()).Distinct().ToList();
colors.Insert(0, String.Empty);
filter.Paint = null;
var ddlColor = (DropDownList)vPanel2.FindControl("ddlColor");
if (ddlColor != null)
{
ddlColor.DataSource = colors;
ddlColor.DataBind();
ddlColor.SelectedIndex = 0;
btnPanel2Next.Enabled = false;
}
else
btnPanel2Next.Enabled = true;
}
else
{
var ddlColor = (DropDownList)vPanel2.FindControl("ddlColor");
if (ddlColor != null)
{
ddlColor.Items.Clear();
ddlColor.SelectedIndex = -1;
}
filter.Engine = null;
btnPanel2Next.Enabled = false;
}
}
protected void ddlColor_SelectedIndexChanged(object sender, EventArgs e)
{
var ddlColor = (DropDownList)vPanel2.FindControl("ddlColor");
var btnPanel2Next = (Button)vPanel2.FindControl("btnPanel2Next");
if (!String.IsNullOrEmpty(ddlColor.SelectedValue))
{
filter.Paint = (PaintColor)Enum.Parse(typeof(PaintColor), ddlColor.SelectedValue);
btnPanel2Next.Enabled = true;
}
else
{
filter.Paint = null;
btnPanel2Next.Enabled = false;
}
}
protected void btnPanel2Prev_Click(object sender, EventArgs e)
{
filter.Engine = null;
filter.Paint = null;
mvPanels.ActiveViewIndex--;
}
protected void btnPanel2Next_Click(object sender, EventArgs e)
{
mvPanels.ActiveViewIndex++;
var selectedConfiguration = availableCars.Where(x => x.Brand == filter.Brand && x.Engine == filter.Engine
&& (!filter.Paint.HasValue || x.Paint == filter.Paint)).Distinct().FirstOrDefault();
if (selectedConfiguration != null)
lblResult.Text = String.Format("You have selected {0} {1} {2} for {3} PLN", selectedConfiguration.Brand,
selectedConfiguration.Engine, selectedConfiguration.Paint, selectedConfiguration.Cost);
}
protected void btnPanel3Prev_Click(object sender, EventArgs e)
{
mvPanels.ActiveViewIndex--;
CreateControlsOnPanel2(true, !filter.EngineOnly);
}
protected void btnPanel3Finish_Click(object sender, EventArgs e)
{
}
}
如果您有任何其他问题，我很乐意为您提供帮助