How to display gif while GridView Process ASP.NET - asp.net

I have an application that displays various data in an ASP.NET GridView. The values ​​are displayed as a selection of combobox. When I select comobo box, the reload process is taking about 8 seconds. I would like to display a gif of load before starting the process and end it cancel the display image. I tried to use a thread for this, but it did not work very well. Could someone help me?
protected void Page_Load(object sender, EventArgs e)
{
//My Image
imageLoad.Visible = true;
Assembly myAsm = Assembly.Load("PainelBordo");
AssemblyName aName = myAsm.GetName();
Version version = aName.Version;
BusinessLogicLayer bll = new BusinessLogicLayer();
LoadDDLWRTG(CreateDataTableWRTGList());
LoadDataPBList();
TimerRefresh.Interval = Convert.ToInt32(ConfigurationManager.AppSettings["TimerInterval"].ToString());
lblUpdateDate.Text = "Refresh " + bll.DateUpdateFormat(DateTime.Now);
// My image
imageLoad.Visible = false;
}
Combobox SelectedIndexChanged.
protected void ddlWRTGroup_SelectedIndexChanged(object sender, EventArgs e)
{
Page_Load(sender, e);
}

Drag and drop a Button(btnInvoke) and Label(lblText) control inside the UpdatePanel. Also add a <div id="divImage"> inside the UpdatePanel. This div will contain a .gif image that depicts progress and is initially set to invisible style="display:none". On the button click, perform a time consuming task. In our case, we have set a delay of 3 seconds by using Thread.Sleep(3000)
C#
protected void btnInvoke_Click(object sender, EventArgs e)
{
System.Threading.Thread.Sleep(3000);
lblText.Text = "Processing completed";
}
Took from here

Related

How to update CheckBoxes on the client side after making changes on the server side?

I have a DropDownList and a CheckBox on my web form. After the DropDownList is clicked and this event is posted back to the server. DropDownList_SelectedIndexChanged event is called on the server side. Inside that event handler, I have CheckBox.Checked = true, But I couldn't make the page on the client side to reflect this change (CheckBox.Checked = true). How do I achieve this? Or am I in the wrong direction to use the DropDownList's event handler to update the CheckBox because the page firstly reloads and then DropDownList_SelectedIndexChanged is called?
Page load method:
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
this.DropDownList1.Items.Clear();
AddItemsToDropDownList();
}
}
DropDownList selected index changed event handler:
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
var selected = this.DropDownList1.SelectedItem.Text;
CheckBox checkBox = GetCheckBoxToBeSetByText(selected);
checkBox.Checked = true;
}
OK. Found the issue. Actually there is nothing wrong with the code in my original post. But to make a smallest sample when I posted, I removed some "extra" code. The below is the "complete" code (OK, fine, I still removed some code). As you can see, I put the CheckBox into a static Dictionary. Each time the SelectedIndexChanged event handler is called, it's modifying the CheckBox in that static Dictionary, which means it's modifying the CheckBox object created from the last session? (still not clear here) Looks like each time when a postback message is received, a new set of CheckBox objects are created. Bear with me if this is known to everybody here already because I only have two days of experience on this web development thing up to today.
private static Dictionary<Environment, CheckBox> EnvironmentsCheckBoxes;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
EnvironmentsCheckBoxes = new Dictionary<Environment,CheckBox>();
EnvironmentsCheckBoxes.Add(Environment.Dev1, this.Dev1_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.Dev2, this.Dev2_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.QA, this.QA_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.QA2, this.QA2_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.Demo, this.Demo_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.Prod, this.Prod_CheckBox);
EnvironmentsCheckBoxes.Add(Environment.UAT, this.UAT_CheckBox);
}
}
protected void DropDownList1_SelectedIndexChanged(object sender, EventArgs e)
{
var selected = this.DropDownList1.SelectedItem.Text;
if (selected == "Dev1")
{
EnvironmentsCheckBoxes[Environment.Dev1].Checked = true;
}
else if (selected == "Dev2")
{
...
}
...
}

Select all items in listbox when updated via UpdatePanel

protected void Page_Load(object sender, EventArgs e)
{
if (ScriptManager.GetCurrent(this).IsInAsyncPostBack)
{
string id = ScriptManager.GetCurrent(Page).AsyncPostBackSourceElementID;
if (id == cboGroup.UniqueID)
{
foreach (ListItem i in lstTest.Items)
i.Selected = true;
}
}
}
This code runs when my cboGroup causes my UpdatePanel to refresh which has the lstTest in it and the data inside of it gets updated, but it does NOT select them all. How can I make it so when my UpdatePanel is finished refreshing all elements of the list box that it refreshed get selected?
[edit] I'm noticing now that at this point what's in the listbox is the previous values and not the new values I would need. So this seems to be before the listbox is filled with data (which is via a SqlDataSource) so it's probably overwriting this.
I was able to put my selection code in the list box's DataBound() event.
protected void lstTest_DataBound(object sender, EventArgs e)
{
SelectAllTest();
}

How do i postback?

I have this web application which is supposed to move rows up and down on button click, but it does only when I close the webpage and re run my program from Visual Studio.
protected void Page_Load(object sender, EventArgs e)
{
if (Page.IsPostBack)
{
DataView view = (DataView)SqlDataSource1.Select(
DataSourceSelectArguments.Empty);
DataTable result = view.ToTable();
}
}
Is this all I need ?
You can use the CommandName to trigger the functionality of your button clicks.
Example: http://msdn.microsoft.com/en-us/library/system.web.ui.webcontrols.linkbutton.commandargument.aspx
You need to use a button click event. You logic is currently in the page load event, that's why its only firing once
You could also remove the if postback which would also work but is not the recommended solution
protected void Page_Load(object sender, EventArgs e)
{
DataView view = (DataView)SqlDataSource1.Select(DataSourceSelectArguments.Empty);
DataTable result = view.ToTable();
}

Handle Button Click Event from User Control loaded dynamically

I have a blank user control (child) and during Page_Load i create some text boxes and a button. I also add an event to the button.
I then load that user control dynamically from a placeholder in another usercontrol (parent).
Both controls are rendered correctly but when i click on the button, the event isnt fired.
Any ideas on how to handle the event?
Child code:
protected void Page_Load(object sender, EventArgs e)
{
/*... other user controls ..*/
UpdateButton = new LinkButton();
UpdateButton.ID = "buttonid";
UpdateButton.Text = "text";
UpdateButton.Click += new EventHandler(UpdateButton_Click);
this.Controls.Add(UpdateButton);
}
protected override void Render(HtmlTextWriter writer)
{
for (int i = 0; i < this.Controls.Count; i++)
{
this.Controls[i].RenderControl(writer);
}
}
public void UpdateButton_Click(object sender, EventArgs e)
{
//Do stuff
}
Parent code:
protected void Page_Load(object sender, EventArgs e)
{
placeholder.Controls.Clear();
ChildControl uc = (ChildControl)LoadControl("~/UserControls/ChildControl.ascx");
placeholder.Controls.Add(uc);
}
If i use the child control directy (ie without the parent the control) the click event is raised and handled nicely. But when i use the parent control, the debugger wont even hit a breakpoint inside UpdateButton_Click().
Thanks in advance.
I think I know what might be happening. In your parent Page_Load you are calling placeholder.Controls.Clear(); This does what you would imagine and clears the control, including any events that have occurred. What happens when remove this line? Do you get an additional one created on each postback?

How can I create an EventHandler inside an EventHandler

I have some code which involves dynamically creating new buttons, when a user clicks on a particular button. However the EventHandlers defined for these dynamically created buttons do not execute when I click on any one of them. Here is the errant code snippet:
protected void Page_Load(object sender, EventArgs e)
{
.......
btn1.Click += new EventHandler(this.btn1_Click);
.......
}
protected void btn1_Click(object sender, EventArgs e)
{
.......
LinkButton btn2 = new LinkButton();
btn2.Click += new EventHandler(this.btn2_Click);
.........
}
protected void btn2_Click(object sender, EventArgs e)
{
.......
}
The code execution never enters btn2_Click(). Am I doing something wrong here?
Try declare LinkButton btn2 as global variable and and wire the event btn2.Click += new EventHandler(this.btn2_Click) as the controls are created.
btn2 disappears as soon as you leave the btn1 event handler. It's a local variable, and goes away as soon as it's out of scope.
Did you ever see the second button? Did you click on it? If so, then you clicked on the wrong button. This one you added never appeared on your page.
In order for a control to become visible (and to render into HTML), it must be placed inside of the Controls collection of a visible control. You're not doing anything with it.

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