Not found anything that directly answers my problem, so hopefully someone can shed some light on it.
I have two Composite Controls, lets call them BudgetTable and BudgetTableItem, where BudgetTable contains a list of BudgetTableItem.
So far everything works so long as I add new RowItems in the HTML View - when I add one programmatically it appears, but doesn't survive postback.
I can only assume I'm doing something boneheaded with ViewState, and would appreciate any pointers!
Thanks in advance.
The HTML:
<hea:BudgetTable runat="server" ID="btTest" MaximumFundingAvailable="7000" CssClass="bob">
<Items>
<hea:BudgetTableItem runat="server" Description="Test1" />
<hea:BudgetTableItem runat="server" Description="Test2" />
<hea:BudgetTableItem runat="server" Description="Test3" />
</Items>
</hea:BudgetTable>
The code behind:
[PersistenceMode(PersistenceMode.InnerProperty)]
[ParseChildren(true)]
public class BudgetTableItem : CompositeControl {
private TextBox _description = new TextBox();
private TextBox _cost = new TextBox();
private CheckBox _heaFunded = new CheckBox();
/*public delegate void AddRow();
public delegate void RemoveRow(BudgetTableItem item);
public event AddRow AddNewRow;
public event RemoveRow RemoveNewRow;*/
public string ItemName {
get {
var viewstate = ViewState["ItemName"];
return (viewstate is string) ? (string)viewstate : "default";
}
set {
ViewState["ItemName"] = value;
}
}
public bool ShowRemoveRow {
get {
var viewstate = ViewState["ShowRemoveRow"];
return (viewstate != null && viewstate is bool) ? (bool)viewstate : false;
}
set {
ViewState["ShowRemoveRow"] = value;
}
}
public bool ShowAddRow {
get {
var viewstate = ViewState["ShowAddRow"];
return (viewstate != null && viewstate is bool) ? (bool)viewstate : false;
}
set {
ViewState["ShowAddRow"] = value;
}
}
public string Description {
get {
return _description.Text;
}
set {
_description.Text = value;
}
}
public decimal Cost {
get {
decimal cost =0;
decimal.TryParse(_cost.Text, out cost);
return cost;
}
set {
_cost.Text = value.ToString();
}
}
public bool HeaFunded {
get {
return _heaFunded.Checked;
}
set {
_heaFunded.Checked = value;
}
}
protected override void CreateChildControls() {
Controls.Clear();
HtmlTableCell tableCell1 = new HtmlTableCell();
HtmlTableCell tableCell2 = new HtmlTableCell();
HtmlTableCell tableCell3 = new HtmlTableCell();
HtmlTableCell tableCell4 = new HtmlTableCell();
tableCell1.Attributes.Add("class", "col1");
tableCell2.Attributes.Add("class", "col2");
tableCell3.Attributes.Add("class", "col3");
tableCell4.Attributes.Add("class", "col4");
tableCell1.Controls.Add(_description);
tableCell2.Controls.Add(_cost);
tableCell3.Controls.Add(_heaFunded);
/*if (ShowAddRow || ShowRemoveRow) {
Button addNewButton = new Button();
addNewButton.Text = (ShowAddRow) ? "Add Row" : "Remove";
if (ShowAddRow) {
addNewButton.Click += new EventHandler(addNewButton_Click);
}
if (ShowRemoveRow) {
addNewButton.Click += new EventHandler(removeButton_Click);
}
tableCell4.Controls.Add(addNewButton);
}
else{*/
tableCell4.InnerHtml = " ";
//}
Controls.Add(tableCell1);
Controls.Add(tableCell2);
Controls.Add(tableCell3);
Controls.Add(tableCell4);
}
/*void addNewButton_Click(object sender, EventArgs e) {
if (AddNewRow != null) {
AddNewRow();
}
}*/
/*void removeButton_Click(object sender, EventArgs e) {
if (RemoveNewRow != null) {
RemoveNewRow(this);
}
}*/
protected override void RecreateChildControls() {
EnsureChildControls();
}
public override void RenderBeginTag(HtmlTextWriter writer) {
writer.Write("<tr>");
}
public override void RenderEndTag(HtmlTextWriter writer) {
writer.Write("</tr>");
}
}
Controls, custom or otherwise that require a ViewState and wish to receive events should be created in Init.
Http is stateless. Your entire page with all its controls is recreated on every postback. Controls that you add in the design view, are added to your designer.cs file, and created for you. When you add controls yourself, you must write code to recreate the controls on every PostBack that occurs later.
You can use the session to remember which controls were added by code and add them on later PostBacks.
Related
I have created a custom web server control that will have a bool property 'RenderAsLabel' so that I can convert textboxes to labels, for Read-only forms. I was wondering if there is any reason why this code should not be safe, or work as intended. Upon initial testing it seems fine, but I just want to make sure I'm not doing something that will end up causing issues.
namespace OrmControlLibrary
{
[DefaultProperty("Text")]
[ToolboxData("<{0}:OrmTextBox ID='' runat=server ></{0}:OrmTextBox>")]
public class OrmTextBox : TextBox
{
private Label lbl;
public virtual bool RenderAsLabel
{
get
{
if (ViewState["OrmTextBox"] == null)
{
return false;
}
else
{
return (bool)ViewState["OrmTextBox"];
}
}
set
{
ViewState["OrmTextBox"] = value;
}
}
protected override void Render(HtmlTextWriter w)
{
if (RenderAsLabel)
{
SetLabelProperties();
lbl.RenderControl(w);
}
else
{
base.Render(w);
}
}
private void SetLabelProperties()
{
lbl = new Label();
lbl.ID = this.ID;
lbl.CssClass = this.CssClass;
lbl.Text = this.Text;
}
}
}
I'm trying to develop a Custom ASP.Net Server Control, which can be manipulated at the client. To save the changes after a Postback there is a hidden field. On the OnLoad event I retrieve the value to write the Property, but it seems too late, because the controls are already built. I know I could manipulate the controls on the PreRender event, but to me it seems there is a better way to handle this. Anyone an idea?
public class Control : CompositeControl {
private bool mProperty;
private HiddenField hiddenField;
public virtual bool Property {
get {
return mProperty;
}
set {
mProperty = value;
}
}
protected override void CreateChildControls() {
Controls.Clear();
CreateControlHierarchy();
ClearChildViewState();
}
protected virtual void CreateControlHierarchy() {
CreateHiddenField();
CreateContent();
}
protected virtual void CreateHiddenField() {
hiddenField = new HiddenField();
hiddenField.ID = "hiddenField";
hiddenField.Value = Property.ToString().ToLower();
Controls.Add(hiddenField);
}
protected virtual void CreateContent() {
contentPanel = new Panel();
contentPanel.ID = "content";
contentPanel.Vsiible = Property;
Controls.Add(contentPanel);
}
protected override void OnLoad(EventArgs e) {
base.OnLoad(e);
if(Page.IsPostback) {
Property = Convert.ToBoolean(Page.Request.Form[hiddenField.UniqueId]);
}
}
}
Edit Possible Solution:
I got rid of the OnLoad event and edited the property like so:
public virtual bool Property {
get {
if (Page.IsPostBack) {
EnsureChildControls();
return Convert.ToBoolean(Page.Request.Form[hiddenField.UniqueID]);
}
return mProperty;
}
set {
mProperty = value;
}
}
Is that a good approach?
One suggestion is to set the post back value both on Property and on control, because the property is used only when the control is created.
protected override void OnLoad(EventArgs e) {
base.OnLoad(e);
if(Page.IsPostback) {
if(hiddenField != null)
hiddenField.Value = Page.Request.Form[hiddenField.UniqueId].ToString();
Property = Convert.ToBoolean(Page.Request.Form[hiddenField.UniqueId].ToString());
}
}
I achieved what I wanted to do, by implementing a ValueChanged EventHandler for the hidden field and edit the setter of the property to take care of all dependencies.
public class Control : CompositeControl {
private bool mProperty;
private HiddenField hiddenField;
public virtual bool Property {
get {
return mProperty;
}
set {
mProperty = value;
if (contentPanel != null) contentPanel.Visible = value;
if (hiddenField != null && hiddenField.Value != value.ToString().ToLower()) hiddenField.Value = value.ToString().ToLower();
}
}
protected override void CreateChildControls() {
Controls.Clear();
CreateControlHierarchy();
ClearChildViewState();
}
protected virtual void CreateControlHierarchy() {
CreateHiddenField();
CreateContent();
}
protected virtual void CreateHiddenField() {
hiddenField = new HiddenField();
hiddenField.ID = "hiddenField";
hiddenField.Value = Property.ToString().ToLower();
hiddenField.ValueChanged += hiddenField_ValueChanged;
Controls.Add(hiddenField);
}
protected virtual void CreateContent() {
contentPanel = new Panel();
contentPanel.ID = "content";
contentPanel.Vsiible = Property;
Controls.Add(contentPanel);
}
void hiddenField_ValueChanged(object sender, EventArgs e) {
Property = Convert.ToBoolean(hiddenField.Value);
}
protected override void OnInit(EventArgs e) {
EnsureChildControls();
base.OnInit(e);
}
}
I have a method that changes the text of the controls on my site.
These changes should be visible right when the user loads the page.
But the changes are first visible after the next postback.
I tried to call it in Page_PreInit, Page_Init, Page_PreLoad and and all the other methods described here.
But none of them worked.
Some code:
The class with the methods: (partly)
namespace MyNamespace {
public class ControlTextCorrection {
Page _page;
public ControlTextCorrection(Page page) {
_page = page;
}
public void Correct() {
HtmlEncodeControls(_page);
}
private void HtmlEncodeControls(Page page) {
Control control = (Control)page;
HtmlEncodeControls(control);
}
private void HtmlEncodeControls(Control parentControl) {
if (!parentControl.HasControls()) {
return;
}
foreach (Control control in parentControl.Controls) {
if (control.HasControls()) {
HtmlEncodeControls(control);
}
if (control is Label) {
Label label = (Label)control;
label.Text = HtmlTextCorrection(label.Text);
}
else if (control is CheckBox) {
CheckBox checkBox = (CheckBox)control;
checkBox.Text = HtmlTextCorrection(checkBox.Text);
}
//Correction for more controls...
}
}
protected string HtmlTextCorrection(string text) {
bool encode = true;
while (encode) {
string newText = _page.Server.HtmlDecode(text);
if (newText == text) {
encode = false;
}
text = newText;
}
text = _page.Server.HtmlEncode(text);
return text;
}
}
}
Example for calling the method:
protected void Page_PreLoad(object sender, EventArgs e) {
ControlTextCorrection correction = new ControlTextCorrection(this.Page);
correction.Correct();
}
So, where (when) should i call it so that the changes are visible at the first sight of the site?
I've created a custom WebControl that implements a simple message box that can display at the top of a web page. Similar to how YouTube displays messages on their pages. My problem is passing the Click event from any button I add to the box down to the ASPX page.
Below is the code for the WebControl. I think I have handling the click events right, but when I add this code to my page, the click event never gets called, although Page_Load does.
Here's the code in the APSX page:
<rt:ConfirmationBox ID="ConfirmationBox1" runat="server" BoxType="Info" BoxButtons="OkayCancel" OnOkayClicked="ConfirmationBoxOkayClicked"
Text="Click OK to close." />
Here's the code in the code behind page:
protected void ConfirmationBoxOkayClicked(object sender, EventArgs e)
{
ConfirmationBox1.BoxButtons = ConfirmationBoxButtons.None;
ConfirmationBox1.BoxType = ConfirmationBoxType.Success;
ConfirmationBox1.Text = "You clicked OK!";
}
Here's the WebControl code:
public enum ConfirmationBoxType
{
Hidden,
Success,
Warn,
Error,
Info
}
public enum ConfirmationBoxButtons
{
None,
Okay,
Cancel,
OkayCancel
}
[DefaultProperty("Text")]
[ToolboxData("<{0}:ConfirmationBox ID=\"ConfirmationBox1\" runat=server></{0}:ConfirmationBox>")]
public class ConfirmationBox : WebControl
{
private static readonly ILog Log = LogManager.GetLogger(typeof(ConfirmationBox));
private Button _okayButton;
private Button _cancelButton;
public event EventHandler OkayClicked;
public event EventHandler CancelClicked;
public virtual void OnOkayClicked(object sender, EventArgs eventArgs)
{
if (OkayClicked != null)
OkayClicked(sender, eventArgs);
}
public virtual void OnCancelClicked(object sender, EventArgs eventArgs)
{
if (CancelClicked != null)
CancelClicked(sender, eventArgs);
}
protected override void OnPreRender(EventArgs e)
{
_okayButton = new Button {ID = "ConfirmBoxOkayButton", CssClass = "button", Text = "OK"};
_okayButton.Click += new EventHandler(OnOkayClicked);
_cancelButton = new Button {ID = "ConfirmBoxCancelButton", CssClass = "button", Text = "Cancel"};
_cancelButton.Click += new EventHandler(OnCancelClicked);
}
[Bindable(true)]
[Category("Appearance")]
[DefaultValue("")]
[Localizable(true)]
public string Text
{
get
{
var s = (String)ViewState["Text"];
return (s ?? String.Empty);
}
set
{
ViewState["Text"] = value;
}
}
[Bindable(true)]
[Category("Appearance")]
[DefaultValue("Hidden")]
public ConfirmationBoxType BoxType
{
get
{
return (ConfirmationBoxType)ViewState["BoxType"];
}
set
{
ViewState["BoxType"] = value;
}
}
[Bindable(true)]
[Category("Appearance")]
[DefaultValue("None")]
public ConfirmationBoxButtons BoxButtons
{
get
{
return (ConfirmationBoxButtons)ViewState["BoxButtons"];
}
set
{
ViewState["BoxButtons"] = value;
}
}
protected override HtmlTextWriterTag TagKey
{
get
{
return HtmlTextWriterTag.Div;
}
}
protected override void AddAttributesToRender(HtmlTextWriter writer)
{
writer.AddAttribute(HtmlTextWriterAttribute.Id, "alerts");
base.AddAttributesToRender(writer);
}
protected override void RenderContents(HtmlTextWriter writer)
{
if (Site != null && Site.DesignMode)
{
writer.Write("[" + ID + "]");
}
else
{
if (BoxType == ConfirmationBoxType.Hidden)
return;
var theme = HttpContext.Current.Profile["UserTheme"].ToString();
writer.AddAttribute(HtmlTextWriterAttribute.Id, "confirmBox");
writer.AddAttribute(HtmlTextWriterAttribute.Class, "rt-alert " + RenderBoxType());
writer.RenderBeginTag(HtmlTextWriterTag.Div);
writer.AddAttribute(HtmlTextWriterAttribute.Src, string.Format("{0}/{1}/pixel.gif", ResolveUrl("~/App_Themes"), (string.IsNullOrEmpty(theme)) ? "Default" : theme));
writer.AddAttribute(HtmlTextWriterAttribute.Class, "icon");
writer.AddAttribute(HtmlTextWriterAttribute.Alt, "Alert icon");
writer.RenderBeginTag(HtmlTextWriterTag.Img);
writer.RenderEndTag();
writer.AddAttribute(HtmlTextWriterAttribute.Class, "rt-alert-content");
writer.RenderBeginTag(HtmlTextWriterTag.Div);
writer.Write(Text);
writer.RenderEndTag();
writer.AddAttribute(HtmlTextWriterAttribute.Type, "button");
writer.AddAttribute(HtmlTextWriterAttribute.Class, "close");
writer.AddAttribute(HtmlTextWriterAttribute.Onclick, "$(\"#alerts\").hide()");
writer.RenderBeginTag(HtmlTextWriterTag.Button);
writer.Write("close");
writer.RenderEndTag();
if (BoxButtons != ConfirmationBoxButtons.None)
{
writer.AddAttribute(HtmlTextWriterAttribute.Class, "rt-alert-buttons");
writer.RenderBeginTag(HtmlTextWriterTag.Div);
if (BoxButtons == ConfirmationBoxButtons.Okay || BoxButtons == ConfirmationBoxButtons.OkayCancel)
_okayButton.RenderControl(writer);
if (BoxButtons == ConfirmationBoxButtons.Cancel || BoxButtons == ConfirmationBoxButtons.OkayCancel)
_cancelButton.RenderControl(writer);
writer.RenderEndTag();
}
writer.RenderEndTag();
}
}
private string RenderBoxType()
{
switch (BoxType)
{
case ConfirmationBoxType.Success:
return "rt-alert-success";
case ConfirmationBoxType.Warn:
return "rt-alert-warn";
case ConfirmationBoxType.Error:
return "rt-alert-error";
case ConfirmationBoxType.Info:
return "rt-alert-info";
}
return string.Empty;
}
}
Create a separate method for your custom event handler, like this:
protected virtual void OnOkayClicked(EventArgs e)
{
if (OkayClicked!= null)
OkayClicked(this, e);
}
Change the name of the button click event and make it protected, like this:
protected void OkayButton_Click(object sender, EventArgs e)
{
//call your event handler method
this.OnOkayClicked(EventArgs.Empty);
}
Test this out, and see if it makes a difference.
I've created a customize web control with the combination of a Label, TextBox and RequiredFieldValidator. To done this, I create a class Field that inherit a Table Control.
namespace WebHRIS.Controls
{
public class Field : Table
{
private Label lblField;
private TextBox tbField;
private RequiredFieldValidator rfvField;
private string _text;
private string _invalidMessage;
private string _clientScript;
private string _controlID;
public virtual string LabelText
{
get { return _text; }
set { _text = value; }
}
public virtual string InvalidMessage
{
get { return _invalidMessage; }
set { _invalidMessage = value; }
}
public virtual string ClientScript
{
get { return _clientScript; }
set { _clientScript = value; }
}
public virtual string ControlID
{
get { return _controlID; }
set { _controlID = value; }
}
protected override void OnInit(EventArgs e)
{
base.OnInit(e);
TableRow tr = new TableRow();
TableCell tc = new TableCell();
lblField = new Label();
lblField.Text = _text;
tc.Controls.Add(lblField);
tr.Cells.Add(tc);
tbField = new TextBox();
tbField.ID = _controlID + this.ID;
tc = new TableCell();
tc.Controls.Add(tbField);
tr.Cells.Add(tc);
rfvField = new RequiredFieldValidator();
rfvField.ControlToValidate = tbField.ID;
rfvField.ErrorMessage = this.InvalidMessage;
rfvField.EnableClientScript = (this.ClientScript.ToLower() != "false");
tc = new TableCell();
tc.Controls.Add(rfvField);
tr.Cells.Add(tc);
this.Rows.Add(tr);
}
protected override void Render(HtmlTextWriter writer)
{
base.Render(writer);
lblField.RenderControl(writer);
}
}
}
This is how I used this control
<%# Register TagPrefix="udc" Namespace="WebHRIS.Controls" Assembly="WebHRIS" %>
<udc:Field ID="fSample" runat="server" LabelText="Sample : " InvalidMessage="ErrorMessage"
ClientScript="false" ControlID="tb" />
Note that this is only a partial code. Now, I'm having a problem like this.
I want to eliminate the 'Sample : ' text. T.I.A
At a glance, I think you're getting the second line of text in you Render method:
protected override void Render(HtmlTextWriter writer)
{
base.Render(writer);
lblField.RenderControl(writer);
}
lblField is the Label control - I would bet that the Label is getting written a second time by the call to lblField.RenderControl(writer). Try removing that line and see if your control will render properly.