最近一个问题一直困扰着我。我希望你能帮助我。
我想在用户点击按钮后创建一个表格。在第一个单元格的每一行，我想添加一个按钮。不幸的是，表格按钮无法触发事件。你能告诉我怎么做或我的错误在哪里吗？我使用this article创建了以下示例代码。
<asp:PlaceHolder ID="placeHolderForTable" runat="server">
</asp:PlaceHolder>
<asp:Button ID="btnCreateTbl" runat="server" Text="Create Table"/>
<asp:Label ID="lblResult" runat="server" />
代码：
private struct ControlInfo
{
public string ID;
public string Type;
public int Border;
public HtmlTableRow[] TblRows;
public HtmlTableCell[] TblCells;
public int Width;
public int Height;
}
protected void Page_Load(object sender, EventArgs e)
{
btnCreateTbl.Click+=new EventHandler(BtnClick);
if (this.IsPostBack) this.RecreatePersistedControls();
}//end Page_Load
//Call CreateControl for each persisted control
private void RecreatePersistedControls()
{
ArrayList al = (ArrayList)this.Session["DynamicControls"];
if (al != null)
foreach (ControlInfo ci in al)
this.CreateControl(ci);
}//end RecreatePersisterdControls method
//Create control specified by ControlInfo structure
private Control CreateControl(ControlInfo ci)
{
Control ctl = null;
switch (ci.Type)
{
case "Button":
ctl = new Button();
ctl.ID = ci.ID;
((Button)ctl).Text = "Edit";
((Button)ctl).Click+=new EventHandler(this.DoNothing);
if (this.placeHolderForTable.FindControl("tblResult") != null)
{
for (int r = 0; r < ci.Height; r++)
{
if (this.placeHolderForTable.FindControl("tblResult").FindControl("tr" + (r + 1)) != null && (r+1).ToString()==ci.ID[7].ToString())
if (this.placeHolderForTable.FindControl("tblResult").FindControl("tr" + (r + 1)).FindControl("td" + (r + 1) + "1") != null)
if(this.placeHolderForTable.FindControl("tblResult").FindControl("tr" + (r + 1)).FindControl("td" + (r + 1) + "1").FindControl(ctl.ID)==null)
this.placeHolderForTable.FindControl("tblResult").FindControl("tr" + (r + 1)).FindControl("td" + (r + 1) + "1").Controls.Add(ctl);
}
}
break;
case "HtmlTable":
ctl = new HtmlTable();
ctl.ID = ci.ID;
((HtmlTable)ctl).Border = ci.Border;
for (int r = 0; r < ci.Height; r++)
{
HtmlTableRow row = ci.TblRows[r];
row.ID = "tr" + (r + 1);
for (int c = r * ci.Width; c < r * ci.Width+2; c++)
{
ci.TblCells[c].ID="td"+(r+1)+(c%2+1);
row.Cells.Add(ci.TblCells[c]);
}
((HtmlTable)ctl).Rows.Add(row);
}
if(this.placeHolderForTable.FindControl(ctl.ID)==null)
this.placeHolderForTable.Controls.Add(ctl);
break;
default:
return null;
}
return ctl;
}//end CreateControl method
//Create ControlInfo structure and persist it to Session
private ControlInfo PersistControl(string id, string type, int border, HtmlTableRow[] tblRows, HtmlTableCell[] tblCells, int width,
int height)
{
ControlInfo ci = new ControlInfo();
ci.ID = id;
ci.Type = type;
ci.Border = border;
ci.TblRows = tblRows;
ci.TblCells = tblCells;
ci.Width = width;
ci.Height = height;
ArrayList al = (ArrayList)this.Session["DynamicControls"];
if (al == null) al = new ArrayList();
al.Add(ci);
this.Session["DynamicControls"] = al;
return ci;
}//end PersistControl method
private void BtnClick(object sender, EventArgs e)
{
int cellIx=0,rowIx=0;
HtmlTableRow tr1 = new HtmlTableRow();
HtmlTableCell td11 = new HtmlTableCell();
tr1.Cells.Add(td11);
HtmlTableCell td12 = new HtmlTableCell();
td12.InnerText = "td12";
tr1.Cells.Add(td12);
HtmlTableRow tr2 = new HtmlTableRow();
HtmlTableCell td21 = new HtmlTableCell();
tr2.Cells.Add(td21);
HtmlTableCell td22 = new HtmlTableCell();
tr2.Cells.Add(td22);
td22.InnerText = "td22";
HtmlTableRow []arrRows=new HtmlTableRow[2];
arrRows[rowIx++]=tr1;
arrRows[rowIx++]=tr2;
HtmlTableCell []arrCells=new HtmlTableCell[4];
arrCells[cellIx++]=td11;
arrCells[cellIx++]=td12;
arrCells[cellIx++]=td21;
arrCells[cellIx++]=td22;
ControlInfo ci = PersistControl("tblResult", "HtmlTable", 3, arrRows, arrCells, 2, 2);
HtmlTable tblResult = (HtmlTable)CreateControl(ci);
ci = PersistControl("btnEdit1", "Button", 0, arrRows, arrCells, 2, 2);
Button btnEdit1 = (Button)CreateControl(ci);
ci = PersistControl("btnEdit2", "Button", 0, arrRows, arrCells, 2, 2);
Button btnEdit2 = (Button)CreateControl(ci);
}
public void DoNothing(object sender, EventArgs e)
{
lblResult.Text = (sender as HtmlButton).ID + " done";
}
答案 0 :(得分：0)
动态控制是另一种野兽，我尽可能地远离它们。话虽如此，但有些情况可能是必要的。
关于事件处理程序和动态控件的事情，您必须确保连接并将控件添加到OnInit或Page_Load函数中的页面控件树，否则它们会表现得很奇怪http://support.microsoft.com/?id=317794
我对您的代码进行了一些编辑，它们在Page_Load中连接了事件处理程序。如果您有任何疑问，请参阅下文并告知我们：
// Added a ViewState persisted prop
bool WireUpControls
{
get
{
return ViewState["wireUpControls"] != null ? Convert.ToBoolean(ViewState["wireUpControls"]) : false;
}
set
{
ViewState["wireUpControls"] = value;
}
}
void CreateControlTable()
{
int cellIx = 0, rowIx = 0;
HtmlTableRow tr1 = new HtmlTableRow();
HtmlTableCell td11 = new HtmlTableCell();
tr1.Cells.Add(td11);
HtmlTableCell td12 = new HtmlTableCell();
td12.InnerText = "td12";
tr1.Cells.Add(td12);
HtmlTableRow tr2 = new HtmlTableRow();
HtmlTableCell td21 = new HtmlTableCell();
tr2.Cells.Add(td21);
HtmlTableCell td22 = new HtmlTableCell();
tr2.Cells.Add(td22);
td22.InnerText = "td22";
HtmlTableRow[] arrRows = new HtmlTableRow[2];
arrRows[rowIx++] = tr1;
arrRows[rowIx++] = tr2;
HtmlTableCell[] arrCells = new HtmlTableCell[4];
arrCells[cellIx++] = td11;
arrCells[cellIx++] = td12;
arrCells[cellIx++] = td21;
arrCells[cellIx++] = td22;
ControlInfo ci = PersistControl("tblResult", "HtmlTable", 3, arrRows, arrCells, 2, 2);
HtmlTable tblResult = (HtmlTable)CreateControl(ci);
ci = PersistControl("btnEdit1", "Button", 0, arrRows, arrCells, 2, 2);
Button btnEdit1 = (Button)CreateControl(ci);
ci = PersistControl("btnEdit2", "Button", 0, arrRows, arrCells, 2, 2);
Button btnEdit2 = (Button)CreateControl(ci);
}
// Call CreateControlTable() if we need to create the controls and wire up events
protected void Page_Load(object sender, EventArgs e)
{
btnCreateTbl.Click += new EventHandler(BtnClick);
if (WireUpControls) CreateControlTable();
//if (this.IsPostBack) this.RecreatePersistedControls();
}
protected void BtnClick(object sender, EventArgs e)
{
WireUpControls = true;
CreateControlTable();
}
public void DoNothing(object sender, EventArgs e)
{
lblResult.Text = (sender as Button).ID + " done";
}