Develop Reference

WPF Set attributes back after a event is finished

so what i would like to is setting back some attributes after an Custom Event is finished.
Scenario i have a save BackupDrives Class that does collection of data and then offers a Event to be called after its done.
Changing object properties can be done by button click, what i would like is to set them back to the same value after the event is finished.
Button click does the thing :
private void bbdrives_Click(object sender, RoutedEventArgs e)
{
backup.SaveDrives += OnSavingDrives;
backup.DrivesSave();
Drive_text.Visibility = Visibility.Visible;
drives_progres.Visibility = Visibility.Visible;
drives_progres.IsIndeterminate = true;
}
Now the triggered event method is not able to change the properties back.
private void OnSavingDrives(object sender, DrivesEventArgs e)
{
Directory.CreateDirectory(....);
File.WriteAllLines(e.Something, e.List2ToSave);
File.WriteAllLines(e.Something_lse, e.List1ToSave);
Drive_text.Visibility = Visibility.Collapsed;
drives_progres.Visibility = Visibility.Collapsed;
drives_progres.IsIndeterminate = false;
}
How do i do this. Since this does not work.
And on other thig here to - when i run the GUI i need to click 2 times one the same button to start it all. Done Code Clean + Rebuild. Still the same.
---EDIT---
As for code here you go.
This is a Class for collecting method and event.
public class DrivesEventArgs : EventArgs
{
string MYDOC = Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments);
const string backup_Drives = "....";
const string backup_Letters = "...";
public List<string> List1ToSave = new List<string>();
public List<string> List2ToSave = new List<string>();
public string SAVE_DRIVE_Letter
{
get
{
string name = Path.Combine(MYDOC, backup_Letters);
return name;
}
}
public string SAVE_DRIVE_Path
{
get
{
string name = Path.Combine(MYDOC, backup_Drives);
return name;
}
}
}
public class DrivesBackup
{
private const string path = "Network";
private List<string> drives_to_save = new List<string>();
private List<string> letters_for_drives = new List<string>();
private RegistryKey reg1, reg2;
public event EventHandler<DrivesEventArgs> SaveDrives;
public void DrivesSave()
{
var data = new DrivesEventArgs();
try
{
if (drives_to_save.Count == 0)
{
reg1 = Registry.CurrentUser.OpenSubKey(path);
string[] mounted_drives = reg1.GetSubKeyNames();
foreach (var drive in mounted_drives)
{ //get all UNC Paths from mounted_drives
string[] getUNC = { path, drive };
string fullUNC = Path.Combine(getUNC);
reg2 = Registry.CurrentUser.OpenSubKey(fullUNC);
string UNCPath = reg2.GetValue("RemotePath").ToString(); //getting UNC PATH
Console.WriteLine(UNCPath);
data.List1ToSave.Add(drive.ToString());
data.List2ToSave.Add(UNCPath);
OnSaveDrives(data);
}
}
}
catch (Exception er)
{
throw er;
}
}
protected virtual void OnSaveDrives(DrivesEventArgs eD)
{
SaveDrives?.Invoke(this, eD);
}
Now here is the MAINWINDOW WPF
public partial class MainWindow : Window
{
DrivesBackup backup = new DrivesBackup();
public MainWindow()
{
InitializeComponent();
}
private void bbdrives_Click(object sender, RoutedEventArgs e)
{
backup.DrivesSave();
backup.SaveDrives += OnSavingDrives;
Drive_text.Visibility = Visibility.Visible;
drives_progres.Visibility = Visibility.Visible;
drives_progres.IsIndeterminate = true;
}
private void OnSavingDrives(object sender, DrivesEventArgs e)
{
Directory.CreateDirectory(System.IO.Path.Combine(Environment.GetFolderPath(Environment.SpecialFolder.MyDocuments), #"SEG-Backup"));
File.WriteAllLines(e.SAVE_DRIVE_Path, e.List2ToSave);
File.WriteAllLines(e.SAVE_DRIVE_Letter, e.List1ToSave);
Drive_text.Visibility = Visibility.Collapsed;
drives_progres.Visibility = Visibility.Collapsed;
drives_progres.IsIndeterminate = false;
}
}
Now i do hope this would make some things more clear.

How to inject Javascript at Document Start using C# on Xamarin Android

I'm trying to port an app from Swift (iOS only) to C# in Visual Studio - and it's going (slightly) well. I'm having some Android troubles though (many of them - but only one for this question!)
The page loads correctly in the webview of the Android version of the app - but the Javascript doesn't execute until after the page has rendered, the result being that the App Store advert is displayed briefly before it disappears.
My iOS app works correctly - the source code for the iOS version is here:
public class PortalViewRenderer : ViewRenderer<PortalView, WKWebView>, IWKScriptMessageHandler, IWKNavigationDelegate {
private class NavigationDelegate : WKNavigationDelegate {
private readonly WeakReference<PortalViewRenderer> _webView;
public NavigationDelegate(PortalViewRenderer webView) {
_webView = new WeakReference<PortalViewRenderer>(webView);
}
public override void DidFinishNavigation(WKWebView webView, WKNavigation navigation) {
}
public override void DidStartProvisionalNavigation(WKWebView webView, WKNavigation navigation) {
NSUrl currentURL = webView.Url;
var current = Connectivity.NetworkAccess;
if (current != NetworkAccess.Internet) {
if (!(currentURL.AbsoluteString.Contains("file://"))) {
string noConnectionPath = Path.Combine(NSBundle.MainBundle.BundlePath, "Common/NoInternet.html");
webView.LoadRequest(new NSUrlRequest(NSUrl.FromString(noConnectionPath)));
}
}
}
public override void DidFailNavigation(WKWebView webView, WKNavigation navigation, NSError error) {
}
public override void DecidePolicy(WKWebView webView, WKNavigationAction navigationAction, Action<WKNavigationActionPolicy> decisionHandler) {
NSUrl url = navigationAction.Request.Url;
if (url != null) {
if (url.Host == "<website url>" || url.AbsoluteString.Contains("file://")) {
decisionHandler(WKNavigationActionPolicy.Allow);
} else if (url.AbsoluteString.Contains("<website url>/mydavylamp/timeout")) {
decisionHandler(WKNavigationActionPolicy.Cancel);
webView.LoadRequest(new NSUrlRequest(NSUrl.FromString(Element.Uri)));
} else {
UIApplication.SharedApplication.OpenUrl(url);
}
}
}
}
WKUserContentController userController;
protected override void OnElementChanged (ElementChangedEventArgs<PortalView> e) {
base.OnElementChanged (e);
var javaScriptFunction = System.IO.File.ReadAllText("Common/HideAppStoreAds.js");
if (Control == null) {
userController = new WKUserContentController();
var script = new WKUserScript(new NSString(javaScriptFunction), WKUserScriptInjectionTime.AtDocumentStart, false);
userController.AddUserScript(script);
userController.AddScriptMessageHandler(this, "invokeAction");
var config = new WKWebViewConfiguration { UserContentController = userController };
var webView = new WKWebView(Frame, config);
webView.BackgroundColor = UIKit.UIColor.FromRGB(0x11, 0x25, 0x43);
webView.ScrollView.BackgroundColor = webView.BackgroundColor;
webView.CustomUserAgent = "headbanger.davylamp.ios";
webView.ScrollView.ScrollEnabled = true;
webView.ScrollView.Bounces = false;
webView.AllowsBackForwardNavigationGestures = false;
webView.ContentMode = UIKit.UIViewContentMode.ScaleToFill;
webView.NavigationDelegate = new NavigationDelegate(this);
SetNativeControl(webView);
}
if (e.OldElement != null) {
userController.RemoveAllUserScripts();
userController.RemoveScriptMessageHandler("invokeAction");
var portalView = e.OldElement as PortalView;
portalView.Cleanup();
}
if (e.NewElement != null) {
Control.LoadRequest(new NSUrlRequest(NSUrl.FromString(Element.Uri)));
}
}
public void DidReceiveScriptMessage (WKUserContentController userContentController, WKScriptMessage message) {
Element.InvokeAction (message.Body.ToString ());
}
}
The Android version is as follows (it doesn't do so much yet, because I haven't worked out how to set policies etc. yet) but my main concern is that I can't get the Javascript to run at the correct time (as set on the iOS version using WKUserScriptInjectionTime which doesn't seem to have an Android equivalent)
public class JavascriptWebViewClient : WebViewClient {
string _javascript;
public JavascriptWebViewClient(string javascript) {
_javascript = javascript;
}
public override void OnPageFinished(WebView view, string url) {
base.OnPageFinished(view, url);
view.EvaluateJavascript(_javascript, null);
}
}
public class PortalViewRenderer : ViewRenderer<PortalView, Android.Webkit.WebView> {
Context _context;
public PortalViewRenderer(Context context) : base(context) {
_context = context;
}
protected override void OnElementChanged(ElementChangedEventArgs<PortalView> e) {
string javascriptFunction;
Android.Content.Res.AssetManager assets = _context.Assets;
using (StreamReader sr = new StreamReader(assets.Open("Common/HideAppStoreAds.js"))) {
javascriptFunction = sr.ReadToEnd();
}
base.OnElementChanged(e);
if (Control == null) {
var webView = new Android.Webkit.WebView(_context);
webView.Settings.JavaScriptEnabled = true;
webView.SetWebViewClient(new JavascriptWebViewClient($"javascript: {javascriptFunction}"));
SetNativeControl(webView);
}
if (e.OldElement != null) {
Control.RemoveJavascriptInterface("jsBridge");
var portalView = e.OldElement as PortalView;
portalView.Cleanup();
}
if (e.NewElement != null) {
Control.LoadUrl($"{Element.Uri}");
}
}
}
The (common) Javascript is as follows:
var styleTag = document.createElement("style");
styleTag.textContent = '.mobile-apps {display:none;}';
document.documentElement.appendChild(styleTag);
I've googled for the magic spell, but I can't seem to find any guides on how to build a webview for Android in C# - and particularly not for iOS developers!
As always, any help that anyone can provide will be gratefully received.

The answer, for my use case, seems to be as follows.
The Android documentation (https://developer.android.com/reference/android/webkit/WebViewClient) for onPageCommitVisible says that:
This callback can be used to determine the point at which it is safe to make a recycled WebView visible, ensuring that no stale content is shown. It is called at the earliest point at which it can be guaranteed that WebView#onDraw will no longer draw any content from previous navigations. The next draw will display either the WebView#setBackgroundColor of the WebView, or some of the contents of the newly loaded page.
To my mind, this means that the HTML has loaded (although not necessarily any other resources) and the page might start to be rendered (although, crucially, it won't be rendered until this callback completes.)
I used the following code:
public override void OnPageCommitVisible(WebView view, string url) {
view.EvaluateJavascript(_javascript, null);
base.OnPageCommitVisible(view, url);
}
and it seems to work correctly. I hope that this helps anyone else.

You need just to override OnPageCommitVisible method:
public override void OnPageCommitVisible(AWebView view, string url)
{
//Insert javascript injection first
view.EvaluateJavascript(_javascript, null);
base.OnPageCommitVisible(view, url);
}
It fires Certainly.
Have a good code!

Dynamic created event in c#

I have a dynamical create button object where I want it to send an event to the mainform when I click on a button inside this object.
I have the code like this :
class Class1
{
internal class FObj_BtnRow
{
private Button[] _Btnmembers;
internal event EventHandler<SelValue_EArgs>[] e_BtnMember; //subscribe to a change
internal class SelValue_EArgs : EventArgs//events args (selected value)
{//return arguments in events
internal SelValue_EArgs(Boolean ivalue) { refreshed = ivalue; }//ctor
internal Boolean refreshed { get; set; }//accessors
}
private Boolean[] _ActONOFFValue; //Pump=0, valveInput = 1, Shower = 3, Washtool = 4 , WashWPcs = 5
private Boolean ActONOFFValue(int number)
{
_ActONOFFValue[number] = !_ActONOFFValue[number];
{
if (e_BtnMember[number] != null && number == 0) e_BtnMember[number](this, new SelValue_EArgs(_ActONOFFValue[number]));
}
return _ActONOFFValue[number];
}
public FObj_BtnRow(String[] TxtBtn, String UnitName)//ctor
{
_Btnmembers = new Button[TxtBtn.Length];
e_BtnMember = new EventHandler<SelValue_EArgs>[TxtBtn.Length];
for (int i = 0; i < TxtBtn.Length / 2; i++)
{
_Btnmembers[i].Click += new EventHandler(_Btnmembers_Click);
}
}
protected virtual void _Btnmembers_Click(object sender, EventArgs e)
{
int index = Array.IndexOf(_Btnmembers, (Button)sender);
ActONOFFValue(index);
}
}
}
But in the line : internal event EventHandler[] e_BtnMember;
the compiler told me that I should use a delegate. I don't understand good this remark, could you help me?
At the end the mainform should only subscribe to the event button click it wants.
And then in main we could use it to now when a button in the object multibutton row is clicked... like this:
public void main()
{
String[] txtbtn = new String[] { "btn1", "btn2", "btn3" };
FObj_BtnRow thisbtnrow = new FObj_BtnRow(txtbtn);
thisbtnrow.e_BtnMember[0] += new EventHandler<FObj_BtnRow.SelValue_EArgs> (btnmember0haschanged);
}
public void btnmember0haschanged(object sender, FObj_BtnRow.SelValue_EArgs newvalue)
{
bool thisnewvalue = newvalue.refreshed;
}
Can you help me?
Thanks in advance!!

I solved the problem by myself, thanks for your advices.
Code
class Class1
{
internal class FObj_BtnRowtest
{
private Button[] _Btnmembers;
public delegate void del_Btnmember(Boolean value);
public del_Btnmember[] btnvaluechanged;
internal class SelValue_EArgs : EventArgs//events args (selected value)
{//return boolean arguments in events
internal SelValue_EArgs(Boolean ivalue) { refreshed = ivalue; }//ctor
internal Boolean refreshed { get; set; }//accessors
}
private Boolean[] _ActONOFFValue;
private Boolean ActONOFFValue(int number)
{
_ActONOFFValue[number] = !_ActONOFFValue[number];
return _ActONOFFValue[number];
}
public FObj_BtnRowtest(int numofbtn, String UnitName)//ctor
{
_Btnmembers = new Button[numofbtn];
btnvaluechanged = new del_Btnmember[numofbtn];
_ActONOFFValue = new bool[numofbtn];
for (int i = 0; i < numofbtn / 2; i++)
{
_Btnmembers[i].Click += new EventHandler(_Btnmembers_Click);
}
}
protected virtual void _Btnmembers_Click(object sender, EventArgs e)
{
int index = Array.IndexOf(_Btnmembers, (Button)sender);
if (btnvaluechanged[index] != null) btnvaluechanged[index](ActONOFFValue(index));
}
}
}
And then in main
thisrow = new Class1.FObj_BtnRowtest(4,"thisunittest");//4 buttons
thisrow.btnvaluechanged[0] += new Class1.FObj_BtnRowtest.del_Btnmember(valuetesthaschanged);//to subscribe to btn0 change
using delegates make it easier. and yes we do need those kinds of stuffs to make code clearer and faster to developp.
Thanks all!!

Overloaded constructor not initializing in another page

I'm working on a project to develop a UWP app.
I'm getting the above mentioned error when I click a button intended to navigate to another frame.
Here's the code of the first frame:
private void Search_Click(object sender, RoutedEventArgs e)
{
Submit();
}
void Submit()
{
DateTime? pickupdate;
pickupdate = PickupDate.Date.DateTime;
DateTime? retdate;
retdate = ReturnDate.Date.DateTime;
Reservation res = new Reservation(pickupdate.Value.ToString("dd-MM-yyyy"), retdate.Value.ToString("dd-MM-yyyy"));
Frame.Navigate(typeof(Reservation));
}
And the code for the second frame:
public Reservation(string pickup, string _return)
{
InitializeComponent();
PickupDateDisplay.Text = pickup;
ReturnDateDisplay.Text = _return;
}
UPDATE:
Ok so I overloaded the Reservation() constructor and now the code for the second frame looks like this:
public Reservation()
{
InitializeComponent();
}
public Reservation(string pickupdate,string retdate)
{
InitializeComponent();
PickupDateDisplay.Text = pickupdate;
ReturnDateDisplay.Text = retdate;
}
Now I don't get any errors on runtime but the PickupDateDisplay.Text and ReturnDateDisplay.Text does not change

This is happening because the Frame.Navigate method that is used for navigation uses parameter less constructor of the given page. To pass parameters to the target page you should use this overload of the method.
void Submit()
{
DateTime? pickupdate = PickupDate.Date.DateTime;
DateTime? retdate = ReturnDate.Date.DateTime;
// This is useless, this instance is not used anywhere (Frame.Navigate creates its own new instance)
// Reservation res = new Reservation(pickupdate.Value.ToString("dd-MM-yyyy"), retdate.Value.ToString("dd-MM-yyyy"));
string[] parameters = { pickupdate.Value.ToString("dd-MM-yyyy"), retdate.Value.ToString("dd-MM-yyyy") };
Frame.Navigate(typeof(Reservation), parameters);
}
Reservation page:
string[] parameters;
public Reservation()
{
Loaded += (sender, e) =>
{
PickupDateDisplay.Text = parameters[0];
ReturnDateDisplay.Text = parameters[1];
}
InitializeComponent();
}
// This ctor is useless too
// public Reservation(string pickupdate,string retdate)
// {
// InitializeComponent();
// PickupDateDisplay.Text = pickupdate;
// ReturnDateDisplay.Text = retdate;
// }
protected override void OnNavigatedTo(NavigationEventArgs e)
{
base.OnNavigatedTo(e);
parameters = (string[])e.Parameter;
}

Adding PushPins in Bing Maps

I am trying to add pushpins to a Bing Map. The push pins are got from a JSON feed. I would like to get something like this:
My code does not work for the first time alone and I cant understand why.
My map ViewModel is
public class MapViewModel : INotifyPropertyChanged
{
public static ObservableCollection<PushpinModel> pushpins = new ObservableCollection<PushpinModel>();
public static ObservableCollection<PushpinModel> Pushpins
{
get { return pushpins; }
set { pushpins = value; }
}
}
The Map xaml cs is:
//Map.xaml.cs
public partial class Map : PhoneApplicationPage
{
#define DEBUG_AGENT
private IGeoPositionWatcher<GeoCoordinate> watcher;
private MapViewModel mapViewModel;
public Map()
{
InitializeComponent();
mapViewModel = new MapViewModel();
this.DataContext = mapViewModel;
}
private void page_Loaded(object sender, RoutedEventArgs e)
{
if (watcher == null)
{
#if DEBUG_AGENT
watcher = new Shoporific.My.FakeGPS();
#else
watcher = new GeoCoordinateWatcher(GeoPositionAccuracy.Default);
#endif
}
watcher.Start();
mapViewModel.Center = watcher.Position.Location;
PushpinModel myLocation = new PushpinModel() { Location = mapViewModel.Center, Content = "My Location" };
MapViewModel.Pushpins.Add(myLocation);
myLocation.RefreshNearbyDeals();
watcher.Stop();
}
}
Finally, the PushPinModelClass:
public class PushPinModel
{
public void RefreshNearbyDeals()
{
System.Net.WebClient wc = new WebClient();
wc.OpenReadCompleted += wc_OpenReadCompleted;
wc.OpenReadAsync(" a valid uri");
}
void wc_OpenReadCompleted(object sender, System.Net.OpenReadCompletedEventArgs e)
{
var jsonStream = e.Result;
DataContractJsonSerializer ser = new DataContractJsonSerializer(typeof(Deal[]));
Deal[] deals = (ser.ReadObject(jsonStream) as Deal[]);
if (deals.Any())
{
var currentLocation = MapViewModel.Pushpins.Where(pin => pin.Content == "My Location");
MapViewModel.Pushpins = new ObservableCollection<PushpinModel>();
foreach (var deal in deals)
MapViewModel.Pushpins.Add(new PushpinModel()
{
Content = deal.Store,
Location = new GeoCoordinate(deal.Location.Latitude, deal.Location.Longtitude),
Offers = deal.Offers,
});
}
}
}
I am a bit confused that the Pushpins except "My Location" dont show up only on the first time. They appear as expected the second time onwards(If I navigate back and then move to the Map screen again).

Inside wc_OpenReadCompleted, you are re-instantiating MapViewModel.Pushpins.
Only call the constructor to an ObservableCollection once (in your case within the MainViewModel). Calling it again messes up the binding that I assume you have in your xaml page.
I believe that you should either remove that line in the PushpinViewModel or call MainViewModel.Pushpins.Clear() instead (depending on what you are trying to accomplish).