I'm approaching to Metro App world in this days, please be gentle.
Here's the problem:
a page receives a string from another page
protected override void OnNavigatedTo(NavigationEventArgs e)
{
Title.Text = e.Parameter.ToString();
}
and I need to pass this string to an User Control of the receiving page.
How can I pass a parameter from a page to an UserControl of another page?
Like this:
Add a property to your user control:
public string MyText { get; set; }
Give your user control a name.
<src:TopBarControl x:Name="MyTopBarControl" />
Then use your NavigatedTo method:
protected override void OnNavigatedTo(NavigationEventArgs e)
{
var _TextParam = e.Parameter.ToString();
this.MyTopBarControl.MyText = _TextParam;
}
This will feed your User Control what it needs.
You could also bind to it by setting the parameter to some public property of the page. If you attempt this approach, please remember to make the User Control's property a Dependency property and not a CLR property. I wrote an article on binding if you want a better explaination http://blog.jerrynixon.com/2012/10/xaml-binding-basics-101.html
Best of luck!
Assuming usercontrol is part of navigated page, you have to do set Property of User Control on OnNavigatedTo override.
Example:
class MyUserControl : UserControl
{
public object Parameter {get;set;}
}
Suppose this user control is part of MyPage
class MyPage : Page
{
private MyUserControl myUserControl; // It is only for illustrations, Otherwise it goes to .designer.cs
protected override void OnNavigatedTo(NavigationEventArgs e)
{
Title.Text = e.Parameter.ToString();
myUserControl.Parameter = e.Parameter; // This is how to set the parameter in usercontrol.
}
}
Related
using xamarin forms & PCL.
i want to validate the Picker using the Behavior to ensure that user picked an item from the Picker.
my behavior class is
public class PickerValidationBehaviour :Behavior<Picker>
{
private Picker _associatedObject;
public string PropertyName { get; set; }
protected override void OnAttachedTo(Picker bindable)
{
base.OnAttachedTo(bindable);
_associatedObject = bindable;
if (_associatedObject.SelectedIndex < 0 )
{
HandleValidation();
}
}
private void HandleValidation()
{
}
private void _associatedObject_SelectedIndexChanged(object sender, EventArgs e)
{
}
protected override void OnDetachingFrom(Picker bindable)
{
base.OnDetachingFrom(bindable);
_associatedObject = null;
}
}
}
and i was stuck because i want execute the validation before user action, such that the submit button will be hidden until the user fill the form.
and beside if there is any easy efficient way that i can perform the validation please mention it.
I think this scenario you should put logic in VM instead of using behavior.
Cause behavior can change some UI element, like color something and most of them are the element itself's property.
In your case, you want to change another element in Page. There is a problem, how to access another element in your page.
If you binding SelectedIndex in you VM, and when property changed you can raise another property which controls the submit button. That will be easier then do it in behavior.
I have gridview bind in user control and want to access that gridview from user control in page and use export to excel.
I created property in usercontrol to access but I am not able to access it.
How can I access gridview from usercontrol in my page?
Why don't you write ExportToExcel method into the user control or just make a property which is public and return the refference to the grid:
public GridView MyGrid
{
get{ return this.GridView1;}
}
I like using interface.
You can create an interface and implement it on the web page. And using a interface object in usercontrol, you can call the interface method.
eg,
Interface
public interface IExport
{
void Export();
}
Your web page
public partial class _Default : System.Web.UI.Page, IExport
{
protected void Page_Load(object sender, EventArgs e)
{
UC11.MyExport = this;
//UC11 will be whatever name of your usercontrol
}
public void Export()
{
//your export code
}
}
And your usercontorl
public partial class UC1 : System.Web.UI.UserControl
{
public IExport MyExport { get; set; }
protected void Page_Load(object sender, EventArgs e)
{
MyExport.Export();
}
}
Hope this helps
if you use Master page for your aspx pages you can access your page GridView in your user control in this way
Page mypage= this.Page;
GridView mypageGridview = (GridView)mypage.Master.FindControl("ContentPlaceHolder1").FindControl("YourGridView");
if you have not master page
Page mypage= this.Page;
GridView mypageGridview = (GridView)mypage.FindControl("YourGridView");
Alright, I am trying to accomplish this: When a user clicks a button that is on a ascx web user control with text boses, it first displays a DIV that is hidden, this div contains a ascx web user control. Basically I want that web user control to grab what they typed in the boxes on the first web user control, and then apply to a SQL search from what the users type in the text boxes on the first page. Is this possible or do I need to rethink my strategy on this? I am programming in c# for the SQL statements.
It is possible.
You can define properties of the control which accepts the text input, and expose the values using direct field access, variables, or session variables; you can then use FindControl from within the newly displayed control, and, if found, utilise the now exposed properties to gather the values required.
For instance, your input control code-behind might look something like this:
partial class MyControl : UserControl
{
public string MyFieldValue
{
get { return MyFieldTextBox.Text; }
}
}
And in the next control, to use it, a little like this:
partial class MyControl : UserControl
{
protected void Page_Load(object sender, EventArgs e)
{
var myControl = Page.FindControl("MyControlInstanceName") as MyControl;
if (myControl != null)
{
var myFieldValue = myControl.MyFieldValue;
}
}
}
Is the 2nd user control embedded in the 1st or not?
If not, you can make anything available upwards between user controls by simply adding public properties to your user controls. This means they can then be accessed from the page level or the containing user control. For example, if I have UCA, UCB, UCC
UCA contains UCB and UCC is hidden.
UCB has the following property
public string UserEnteredName
{
get { return NameTextBox.Text; }
}
UCC has the following property and method
public string UserEnteredName { get; set; }
public BindResults()
{
UserEnteredLiteral.Text = UserEnteredName;
}
Then tie it together with UCA:
protected MyButton_Click(object sender, EventArgs e)
{
UCC.UserEnteredName = UCB.UserEnteredName;
... some logic herre.
UCC.BindResults();
}
You can also raise an event from UCB that can be responded to in UCA if your button or submit action exists in UCB.
How can I pass user control properties to the page AND make these properties available to all methods on the page (and not just to one method that is fired on a control action, e.g. onControlClick)
I have a set up of essentially 3 pages:
user control (ascx/cs)
class (cs) - that contains user control properties
host page (aspx/cs) - references the user control
The user control consists of 3 interrelated dropdowns. I'm having success passing these dropdown values through a class onto the page via an event that is fired when a user clicks on the dropdown menu. So this way the host page is continously aware of the values in the user control. However, I want the page to use the control's properties (stored in a class) on all of its methods - how do I make this user control class available to all?
Also I'm using ASP.NET and C# by the way.
Here's the Code (not sharing the full code here - just the snippets of a similar code block)
On the ASPX for Menu Host Page:
<linked:LinkMenu2 id="Menu1" runat="server" OnLinkClicked="LinkClicked" />
Host Page (cs):
protected void dropdownclicked(object sender, ddtestEventArgs e)
{
if (e.Url == "Menu2Host.aspx?product=Furniture")
{
lblClick.Text = "This link is not allowed.";
e.Cancel = true;
}
else
{
// Allow the redirect, and don't make any changes to the URL.
}
}
Host Page (aspx)
<asp:dropdowncustom ID="dddone" runat="server" OnddAppClicked="dropdownclicked" />
Control (cs)
public partial class usercontrol_tests_dropdown1 : System.Web.UI.UserControl
{
public event ddtestEventHandler ddAppClicked;
}
public void selectapp_SelectedIndexChanged(object sender, EventArgs e)
{
ddtestEventArgs args = new ddtestEventArgs(selectlink.SelectedValue);
ddAppClicked(this, args);
}
Class:
public class ddtestEventArgs : EventArgs
{
// Link
private string link;
public string Link
{
get { return link; }
set { link = value; }
}
public ddtestEventArgs(string link)
{
Link = link;
}
}
public delegate void ddtestEventHandler(object sender, ddtestEventArgs e);
Hopefully this is what you're after. The best way to do it is to expose your controls as public properties from your user control. So, in your user control, for each drop down list add a property:
public DropDownList DropDown1
{
get { return dropDownList1; }
}
public DropDownList DropDown2
{
get { return dropDownList2; }
}
You can do the same for any other properties you want to access on the host page:
public string DropDown1SelectedValue
{
get { return dropDownList1.SelectedValue; }
set { dropDownList1.SelectedValue = value; }
}
Then, from your host page you can access the properties through the user control:
string value = UserControl1.DropDown1SelectedValue;
or
string value = UserControl1.DropDownList1.SelectedValue;
Here's a couple of other answered questions that you might find useful as I think (if I've understood correctly) this is what you're doing:
Getting data from child controls loaded programmatically
How to change the value of a control in a MasterPage.
Lets say i have this usercontrol
public class test : UserControl {
public int Count { get; set; }
public test() {
Count = 3;
}
public override DataBind() {
aRepeater.DataSource = dal.GetObjects(Count);
base.DataBind();
}
}
and i use it on my page like this
<my:test runat="server" Count="<# something %>" />
my problem now is that i am not able to get the value of Count in my usercontrol before after the call to base.DataBind(). I guess its something with databinding values to itself. The workaround sofar has therefor been
public override DataBind() {
base.DataBind(); // to bind values to self
aRepeater.DataSource = dal.GetObjects(Count);
base.DataBind(); // to bind new values that is dependent on the the first bind
}
It works, but it just doesn't seem right. My question is therefor whats the best practices is for this scenario.
Just override OnDataBinding method, not DataBind:
protected override void OnDataBinding(EventArgs e) {
base.OnDataBinding(e);
aRepeater.DataSource = dal.GetObjects(Count);
}
DataBind method essentially consists of two steps: 1) OnDataBinding(), 2) DataBind() for each child control.
It makes sense, because Count="<# something %>" occurs at DataBind(). I think you should handle all the data binding at DataBind() in this case (and not to use page binding methods). Of course this is only a matter of beautifying the code - nothing more.
Do you have to set the Count property of your user control in you .ascx file? How about not having a Count property at all or setting Count in the code behind of the page that includes the user control?
<my:test runat="server" id="test1" />
Code behind:
//User control code behind. GetCount() returns an int.
public override DataBind() {
aRepeater.DataSource = dal.GetObjects(GetCount());
base.DataBind();
}
or
//Page that has the user control.
protected void Page_Load(object sender, EventArgs e)
{
this.test1.Count = 5;
}
//User control code behind.
public override DataBind()
{
aRepeater.DataSource = dal.GetObjects(this.Count);
base.DataBind();
}