I have the following code and some images listed in a DataList:
protected void btnDel_Click(object sender, EventArgs e)
{
if (Id != 0)
{
BaseClass.Delete(Id1);
string path = Path.Combine(GetDirectory(Name), Name);
File.Delete(path);
}
}
public void BindImages()
{
path = BaseClass.GetAllImages(PId);
for (int i = 0; i < path.Count; i++)
{
ArrayList lst = path[i];
tb.Rows.Add(Convert.ToInt32(lst[0]), lst[1].ToString(),
lst[2].ToString(), i);
}
dlst1.DataSource = tb;
dlst1.DataBind();
}
When I click on the delete button for an image the image is removed but when I rebind the DataList the images are being duplicated.
I am binding the DataList in my PageLoad method.
You have to use IsPostBack boolean property in the Page_Load handler.
protected void page_load()
{
if(!IsPostBack)
{
BindImages();
}
}
Related
I am using visual studio 2010 and crystal report 13.0
The report viewer displays the first page properly. But the next page button is not working. If i click on next page button then it shows loading message and stays there only.None of the report viewer controls are working.
please help me out
I found the solution.
Manually add the Page_Init() event and wire it up in the InitializeCompnent() with
this.Init += new System.EventHandler(this.Page_Init).
Move the contents of Page_Load to Page_Init().
Add if (!IsPostBack) condition in PageInIt.
protected void Page_Init(object sender, EventArgs e)
{
if (!IsPostBack)
{
ReportDocument crystalReportDocument = new ReportDocumment();
crystalReportDocument.SetDataSource(DataTableHere);
_reportViewer.ReportSource = crystalReportDocument;
Session["ReportDocument"] = crystalReportDocument;
}
else
{
ReportDocument doc = (ReportDocument)Session["ReportDocument"];
_reportViewer.ReportSource = doc;
}
}
Instead of manually identifying the moment to bind, you could use the CrystalReportViewer AutoDataBind property in combination with the DataBinding event.
Autobind definition:
// Summary:
// Boolean. Gets or sets whether automatic data binding to a report source is
// used. If the value is set to True, the DataBind() method is called after
// OnInit() or Page_Init().
[Category("Data")]
[DefaultValue(false)]
[DesignerSerializationVisibility(DesignerSerializationVisibility.Visible)]
public bool AutoDataBind { get; set; }
You could use this property in the following manner:
In the ASPX:
<CR:CrystalReportViewer ID="_reportViewer" runat="server" AutoDataBind="true" OnDataBinding="_reportViewer_DataBinding" />
And in the ASPX.CS:
protected void _reportViewer_DataBinding(object sender, EventArgs e)
{
if (!IsPostBack)
{
ReportDocument crystalReportDocument = new ReportDocumment();
crystalReportDocument.SetDataSource(DataTableHere);
_reportViewer.ReportSource = crystalReportDocument;
Session["ReportDocument"] = crystalReportDocument;
}
else
{
ReportDocument doc = (ReportDocument)Session["ReportDocument"];
_reportViewer.ReportSource = doc;
}
}
Done! Shift your Page load Event to Page Init Event.
protected void Page_Load(object sender, EventArgs e)
{
if (IsPostBack)
{
int pageIndex =((CrystalDecisions.Shared.PageRequestContext)
CrystalReportViewer1.RequestContext).PageNumber;
//Bind Report with filter and datasource
string ControID = GetPostBackControlName(this);
//get and check Crystal Report Navigation button event after Bind Report
if (ControID == null)
{
((CrystalDecisions.Shared.PageRequestContext)
CrystalReportViewer1.RequestContext).PageNumber = pageIndex;
}
}
}
public string GetPostBackControlName(Page Page)
{
Control control = null;
string ctrlname = Page.Request.Params["__EVENTTARGET"];
if (ctrlname != null && ctrlname != String.Empty)
{
control = Page.FindControl(ctrlname);
}
else
{
string ctrlStr = String.Empty;
Control c = null;
foreach (string ctl in Page.Request.Form)
{
if (ctl.EndsWith(".x") || ctl.EndsWith(".y"))
{
ctrlStr = ctl.Substring(0, ctl.Length - 2);
c = Page.FindControl(ctrlStr);
}
else
{
c = Page.FindControl(ctl);
}
if (c is System.Web.UI.WebControls.Button ||
c is System.Web.UI.WebControls.ImageButton)
{
control = c;
break;
}
}
}
if (control == null)
{
return null;
}
else
{
return control.ID;
}
}
I have gridview built dynamically at run-time bind to datatable, and button to save gridview data placed outside gridview
1- Create GridView
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
CreateGrid();
}
}
void CreateGrid()
{
int nTransID = Convert.ToInt32(Session["trans_id"]);
//
string strSQL = #"EXEC [dbo].[sp_GetTransaction] " + nTransID;
DataTable dtData = clsGlobal.GetDataTable(strSQL);
//
if (ViewState["dtTransDetail"] == null) ViewState.Add("dtTransDetail", dtData);
else ViewState["dtTransDetail"] = dtData;
//
foreach (DataColumn dc in dtData.Columns)
{
if (dc.ColumnName.Contains("!;"))
{
TemplateField tField = new TemplateField();
tField.ItemTemplate = new AddTemplateToGridView(ListItemType.Item, dc.ColumnName);
//\\ --- template contain textbox
tField.HeaderText = dc.ColumnName;
GridView1.Columns.Add(tField);
}
}
}
This is my template class:
public class AddTemplateToGridView : ITemplate
{
ListItemType _type;
string _colName;
public AddTemplateToGridView(ListItemType type, string colname)
{
_type = type;
_colName = colname;
}
void ITemplate.InstantiateIn(System.Web.UI.Control container)
{
switch (_type)
{
case ListItemType.Item:
TextBox text = new TextBox();
text.ID = "txtAmount";
text.DataBinding += new EventHandler(txt_DataBinding);
container.Controls.Add(text);
break;
}
}
void txt_DataBinding(object sender, EventArgs e)
{
TextBox textBox = (TextBox)sender;
GridViewRow container = (GridViewRow)textBox.NamingContainer;
object dataValue = DataBinder.Eval(container.DataItem, _colName);
if (dataValue != DBNull.Value)
{
textBox.Text = dataValue.ToString();
}
}
}
So i have a gridview with textboxe's all open to edit at once
The problem is, when i click on Save button "which is outside gridview" all textboxe's gone
protected void btnSave_Command(object sender, CommandEventArgs e)
{
for (int nRow = 0; nRow < GridView1.Rows.Count; nRow++)
{
for (int nCol = 0; nCol < GridView1.Columns.Count; nCol++)
{
if (GridView1.Rows[nRow].Cells[nCol].Controls.Count == 0) continue;
//\\ --- Controls.Count always = 0
//\\ --- However each cell contain textbox
//\\ --- textbox disappear after save button clicked
TextBox txt = (TextBox)GridView1.Rows[nRow].Cells[nCol].Controls[0];
}
}
}
It looks like you are not creating the GridView after a postback, and the Save button is causing a postback. You need to dynamically create the GridView on each page load. Also, I have found this documentation on the ASP.NET page lifecycle helpful on numerous occasions.
In the documentation, you will see the slightly unintuitive reason why your code isn't working as you would like - btnSave_Command is not run until after a postback and Page_Load.
namespace Dynamic_Controls.Dropdowndynamic
{
public partial class DropdowndynamicUserControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
if (ControlCount != 0)
{
Recreatecontrols();
}
}
private void Recreatecontrols()
{
// createtextboxes(ControlCount);
createtextboxes(2);
}
protected void createtextboxes(int ControlCount)
{
DynPanel.Visible = true;
for (int i = 0; i <= ControlCount; i++)
{
TextBox tb = new TextBox();
tb.Width = 150;
tb.Height = 18;
tb.TextMode = TextBoxMode.SingleLine;
tb.ID = "TextBoxID" + this.DynPanel.Controls.Count;
tb.Text = "EnterTitle" + this.DynPanel.Controls.Count;
tb.Load+=new EventHandler(tb_Load);
tb.Visible = true;
tb.EnableViewState = true;
DynPanel.Controls.Add(tb);
DynPanel.Controls.Add(new LiteralControl("<br/>"));
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
Int32 newControlCount = Int32.Parse(DropDownList1.SelectedValue);
//createtextboxes(newControlCount);
//ControlCount+=newControlCount;
createtextboxes(2);
}
protected void Button1_Click(object sender, EventArgs e)
{
readtextboxes();
}
public void readtextboxes()
{
string x = string.Empty;
for (int a = 0; a < DynPanel.Controls.Count; a++)
{
foreach (Control ctrl in DynPanel.Controls)
{
if (ctrl is TextBox)
{
x = ((TextBox)ctrl).Text;
}
x+=x+("\n");
}
Result.Text = x;
}
}
private Int32 ControlCount
{
get
{
if (ViewState["ControlCount"] == null)
{
ViewState["ControlCount"] = 0;
}
return (Int32)ViewState["ControlCount"];
}
set
{
// ViewState["ControlCount"] = value;
ViewState["ControlCount"] = 2;
}
}
private void tb_Load(object sender, EventArgs e)
{
LblInfo.Text = ((TextBox)sender).ID + "entered";
}
}
}
Are you adding these controls dynamically in Page_Load (by, I'm assuming, calling your AddRequiredControl() method)? If so, is it wrapped in a conditional which checks for IsPostBack? The likely culprit is that you're destructively re-populating the page with controls before you get to the button click handler, so all the controls would be present but empty (as in an initial load of the page).
Also, just a note, if you're storing each control in _txt in your loop, why not refer to that variable instead of re-casting on each line. The code in your loop seems to be doing a lot of work for little return.
You need to recreate any dynamically created controls on or before Page_Load or they won't contain postback data.
I'm not entirely clear what happens on DropdownList changed - are you trying to preserve anything that has been entered already based on the textboxes previously generated?
In any event (no pun intended) you need to recreate exactly the same textboxes in or before Page_Load that were there present on the postback, or there won't be data.
A typical way to do this is save something in ViewState that your code can use to figure out what to recreate - e.g. the previous value of the DropDownList. Override LoadViewState and call the creation code there in order to capture the needed value, create the textboxes, then in the DropDownList change event, remove any controls that may have been created in LoadViewState (after of course dealing with their data) and recreate them based on the new value.
edit - i can't figure out how your code works now, you have AddRequiredControl with parameters but you call it with none. Let's assume you have a function AddRequiredControls that creates all textboxes for a given DropDownList1 value, and has this signature:
void AddRequiredControls(int index)
Let's also assume you have a PlaceHolder called ControlsPlaceholder that will contain the textboxes. Here's some pseudocode:
override void LoadViewState(..) {
base.LoadViewState(..);
if (ViewState["oldDropDownIndex"]!=null) {
AddRequiredControls((int)ViewState["oldDropDownIndex"]);
}
}
override OnLoad(EventArgs e)
{
// process data from textboxes
}
void DropDownList1_SelectedIndexChanged(..) {
ControlsPlaceholder.Controls.Clear();
AddRequiredControls(DropDownList1.SelectedIndex);
ViewState["oldDropDownIndex"]=DropDownList1.SelectedIndex;
}
I Add Control Dynamiclly but; easc Postback event my controls are gone. I Can not see again my controls.
So How can I add control ?
Because you must recreate your controls on every postback,
see this article
Add the controls in the Page's Init event and they will be preserved in viewstate when posting back. Make sure they have a unique ID.
See this link...
ASP.NET Add Control on postback
A very trivial example..
public partial class MyPage : Page
{
TextBox tb;
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
tb = new TextBox();
tb.ID = "testtb";
Page.Form.Controls.Add(tb);
}
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);
//tb.Text will have whatever text the user entered upon postback
}
}
You should always assign a unique ID to the UserControl in its ID property after control is loaded. And you should always recreate UserControl on postback.
To preserve posback data (i.e. TextBox'es) you must load UserControl in overriden LoadViewState method after calling base.LoadViewState - before postback data are handled.
Add controls in runtime and save on postback:
int NumberOfControls = 0;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
ViewState["b1"] = 0;
}
else
{
if ((int)ViewState["b1"] > 0)
{
CreateBtn();
}
}
}
protected void btn1_Click(object sender, EventArgs e)
{
NumberOfControls = (int)ViewState["b1"];
Button b1 = new Button();
// b1.Attributes.Add("onclick", "x()");
b1.Text = "test2";
b1.ID = "b1_" + ++NumberOfControls;
b1.Click +=new System.EventHandler(btn11);
Panel1.Controls.Add(b1);
ViewState["b1"] = NumberOfControls;
}
protected void CreateBtn()
{
for (int i = 0; i < (int)ViewState["b1"];i++)
{
Button b1 = new Button();
// b1.Attributes.Add("onclick", "x()");
b1.Text = "test2";
b1.ID = "b1_" + i;
b1.Click += new System.EventHandler(btn11);
Panel1.Controls.Add(b1);
}
}
protected void btn11(object sender, System.EventArgs e)
{
Response.Redirect("AboutUs.aspx");
}
In my asp.net application i have created checkboxes at runtime. I want to disable the checked checkbox when i click on a button. How do I achieve this? Here is my code:
protected void Page_Load(object sender, EventArgs e)
{
for (int i = 0; i < 12; i++)
{
tr = new TableRow();
tr.BorderStyle = BorderStyle.Groove;
for (int j = 0; j < 18; j++)
{
tc = new TableCell();
tc.BorderStyle = BorderStyle.Groove;
ch = new CheckBox();
tc.Controls.Add(ch);
tr.Cells.Add(tc);
}
Table1.Rows.Add(tr);
}
if(!IsPostBack)
{
form1.Controls.Add(ch);
mRoleCheckBoxList.Add("RoleName", ch);
}
}
protected void Button1_Click(object sender, EventArgs e)
{
IDictionaryEnumerator RoleCheckBoxEnumerator = mRoleCheckBoxList.GetEnumerator();
while (RoleCheckBoxEnumerator.MoveNext())
{
CheckBox RoleCheckBox = (CheckBox)RoleCheckBoxEnumerator.Value;
string BoxRoleName = (string)RoleCheckBox.Text;
if (RoleCheckBox.Checked == true)
{
RoleCheckBox.Enabled = false;
break;
}
}
}
One rule-of-thumb while dealing with dynamically generated user controls is that you have to add them to the container on EVERY POSTBACK.
Just modify your code to generate the controls on every postback, and your code will start working like a charm!
EDIT
I am unsure what the ch variable is. I have assumed that its a checkbox. If I am correct, then all you have to do is to modify these lines
if(!IsPostBack)
{
form1.Controls.Add(ch);
mRoleCheckBoxList.Add("RoleName", ch);
}
to this
//if(!IsPostBack)
{
form1.Controls.Add(ch);
mRoleCheckBoxList.Add("RoleName", ch);
}
EDIT 2
This is the code for generating 10 checkboxes dynamically -
protected void Page_Init(object sender, EventArgs e)
{
CheckBox c = null;
for (int i = 0; i < 10; i++)
{
c = new CheckBox();
c.ID = "chk" + i.ToString();
c.Text = "Checkbox " + (i + 1).ToString();
container.Controls.Add(c);
}
}
Check the checkboxes when the page renders on the client side, click the button. This will cause a postback and the checkboxes will be generated again. In the click event of the button, you'll be able to find the checkboxes like this -
protected void Button1_Click(object sender, EventArgs e)
{
CheckBox c = null;
for (int i = 0; i < 10; i++)
{
c = container.FindControl("chk" + i.ToString()) as CheckBox;
//Perform your relevant checks here, and disable the checkbox.
}
}
I hope this is clear.
Maybe
RoleCheckBox.Parent.Controls.Remove(RoleCheckBox);
You are not getting a proper reference to your checkboxes - mRoleCheckBoxList is not mentioned as part of your checkbox creation.
Try the following in your button event handler:
foreach (TableRow row in Table1.Rows)
foreach (TableCell cell in row.Cells)
{
CheckBox check = (CheckBox)cell.Controls[0];
if (check.Checked) check.Enabled = false;
}
Always when creating dynamic controls in .Net create them here:
protected override void CreateChildControls()
{
base.CreateChildControls();
this.CreateDynamicControls();
} //eof method
and in the PostBack find the them either from the event trigger or from a non-dynamic control:
/// <summary>
/// Search for a control within the passed root control by the control id passed as string
/// </summary>
/// <param name="root">the upper control to start to search for</param>
/// <param name="id">the id of the control as string</param>
/// <returns></returns>
public virtual Control FindControlRecursively(Control root, string id)
{
try
{
if (root.ID == id)
{
return root;
} //eof if
foreach (Control c in root.Controls)
{
Control t = this.FindControlRecursively( c, id);
if (t != null)
{
return t;
} //eof if
} //eof foreach
} //eof try
catch (Exception e)
{
return null;
} //eof catch
return null;
} //eof method