I try to update twice with same data but it throw exception
public void UpdateOnSubmit<T>(T data) where T : class
{
lock (_lockObj)
{
using (DataModel dx = new DataModel(this._adapter.ConnectionString))
{
dx.GetTable<T>().Attach(data);
dx.Refresh(RefreshMode.KeepCurrentValues, data);
dx.SubmitChanges();
}
}
}
the exception is
An attempt has been made to Attach or Add an entity that is not new, perhaps having been loaded from another DataContext. This is not supported.
First update is success but not in second. Thanks in advance
Regards,
Brian
Okay seem like i've found the solution again. I Just set DeferredLoadingEnabled to false and it work like a charm.
public void UpdateOnSubmit<T>(T data) where T : class
{
lock (_lockObj)
{
using (DataModel dx = new DataModel(this._adapter.ConnectionString))
{
dx.DeferredLoadingEnabled = false;
dx.GetTable<T>().Attach(data);
dx.Refresh(RefreshMode.KeepCurrentValues, data);
dx.SubmitChanges();
}
}
}
Related
I need to print a picture on client side. I used this as a template. My PrintUI looks like this:
#Override
protected void init(VaadinRequest request) {
Item item = ..get item ..
StreamResource imageStream = ... build image dynamically ...
Image image = new Image(item.getName(), imageStream);
image.setWidth("100%");
setContent(image);
setWidth("100%");
// Print automatically when the window opens
JavaScript.getCurrent().execute("setTimeout(function() {print(); self.close();}, 0);");
}
This works so far in IE but in chrome it opens the printing preview showing an empty page. The problem is that the image is loaded in some way that chrome does not wait for it and starts the printing preview immideatly.
To verify this, I tried: (setting a 5sec timeout)
JavaScript.getCurrent().execute("setTimeout(function() {print(); self.close();}, 0);");
Then it works in IE and Chrome, but its of course an ugly hack, and if the connection is slower than 5sec, then again it will fail.
In pure JS it would work like this, but Im not sure how to reference the element from vaadin in cient-side js. Any ideas?
You can use AbstractJavascriptExtension.
Example extension class:
#JavaScript({ "vaadin://scripts/connector/wait_for_image_load_connector.js" })
public class WaitForImageLoadExtension extends AbstractJavaScriptExtension {
private List<ImageLoadedListener> imageLoadedListeners = new ArrayList<>();
public interface ImageLoadedListener {
void onImageLoaded();
}
public void extend(Image image) {
super.extend(image);
addFunction("onImageLoaded", new JavaScriptFunction() {
#Override
public void call(JsonArray arguments) {
for (ImageLoadedListener imageLoadedListener : imageLoadedListeners) {
if (imageLoadedListener != null) {
imageLoadedListener.onImageLoaded();
}
}
}
});
}
public void addImageLoadedListener(ImageLoadedListener listener) {
imageLoadedListeners.add(listener);
}
}
and javascript connector (placed in wait_for_image_load_connector.js) with the waiting method you have linked:
window.your_package_WaitForImageLoadExtension = function() {
var connectorId = this.getParentId();
var img = this.getElement(connectorId);
if (img.complete) {
this.onImageLoaded();
} else {
img.addEventListener('load', this.onImageLoaded)
img.addEventListener('error', function() {
alert('error');
})
}
}
Then you can do something like that:
Image image = new Image(item.getName(), imageStream);
WaitForImageLoadExtension ext = new WaitForImageLoadExtension();
ext.extend(image);
ext.addImageLoadedListener(new ImageLoadedListener() {
#Override
public void onImageLoaded() {
JavaScript.eval("print()");
}
});
In your case, when calling print() is the only thing you want to do after the image is loaded, you can also do it without server-side listener by just calling it in the connector:
if (img.complete) {
print();
} else {
img.addEventListener('load', print)
img.addEventListener('error', function() {
alert('error');
})
}
Let's go straight to an example. Let's say we have:
Update(){
if (value.Equals("circular")) moveGameObjectInACircularWay();
else if (value.Equals("linear")) moveGameObjectInALinearWay();
}
I think that is not very elegant solution. Unity needs to perform a comparison every frame. That does not sound very optimal to me. I'm just guessing it should be some other way to implement the same like:
Start () {
if (value.Equals("circular")) movement += moveGameObjectInACircularWay;
else if (value.Equals("linear")) movement += moveGameObjectInALinearWay;
}
Update () {
movement();
}
I guess the solution is related with delegates. That's why my proposed solution looks like delegates. I don't understand what delegates are well yet.
From MSDN "A delegate in C# is similar to a function pointer in C or C++. Using a delegate allows the programmer to encapsulate a reference to a method inside a delegate object." (https://msdn.microsoft.com/en-us/library/aa288459(v=vs.71).aspx) In short is a pointer to a method. What you want to do is the following:
using UnityEngine;
using System.Collections;
public delegate void MovementDelegate();
public class Movement : MonoBehaviour {
MovementDelegate movementFunction=null;
public string value = "linear";
void Start () {
if (value.Equals("circular")) movementFunction = moveGameObjectInACircularWay;
else if (value.Equals("linear")) movementFunction = moveGameObjectInALinearWay;
}
// Update is called once per frame
void Update()
{
if (movementFunction != null)
{
movementFunction();
}
}
void moveGameObjectInACircularWay()
{
Debug.Log("do circular movement here");
}
void moveGameObjectInALinearWay()
{
Debug.Log("do linear movement here");
}
}
The functions you declare must have the same signature as the delegate signature. If you want to add parameters to it, ex. an int, decalre your delegate as
public delegate void MovementDelegate(int speed);
and your implementation functions as
void moveGameObjectInACircularWay(int speed)
void moveGameObjectInALinearWay(int speed)
and change the call to
movementFunction(yourIntHere)
UPDATED!: Thanks to Joe Blow suggestion here is another solution:
public class Movement : MonoBehaviour
{
Action<int> movementFunction = null;
public string value = "linear";
void Start()
{
if (value.Equals("circular")) movementFunction = moveGameObjectInACircularWay;
else if (value.Equals("linear")) movementFunction = moveGameObjectInALinearWay;
}
// Update is called once per frame
void Update()
{
if (movementFunction != null)
{
movementFunction(2);
}
}
void moveGameObjectInACircularWay(int speed)
{
Debug.Log("do circular movement here "+ speed);
}
void moveGameObjectInALinearWay(int speed)
{
Debug.Log("do linear movement here " + speed);
}
}
My favorite answer has been written by Joe Blow in the comments:
Unity is components based. We better switch to Component-Based Thinking instead working with delegates.
So make two (or more) different scripts, and put those on the game object in question. Then, turn on and off these components as you wish.
So we would have to scripts added to our game object: MoveGameObjectInACircularWay.cs and MoveGameObjectInALinearWay.cs. Then a MainGameObjectScript.cs also added to our game object with the following code:
void Start () {
GetComponent()<MoveGameObjectInACircularWay>.active = true;
GetComponent()<MoveGameObjectInALinearWay>.active = false;
}
I'm already seeking all day for a solution. I'm a MVVM-beginner and I have the following problem.
This is the code of my viewmodelLocator:
static ViewModelLocator()
{
ServiceLocator.SetLocatorProvider(() => SimpleIoc.Default);
if (ViewModelBase.IsInDesignModeStatic)
{
// Create design time view services and models
SimpleIoc.Default.Register<IDataService, DesignDataService>();
}
else
{
// Create run time view services and models
//SimpleIoc.Default.Register<IDataService,DataService>();
SimpleIoc.Default.Register<IDataService, OleDbDataService>();
}
SimpleIoc.Default.Register<A>();
SimpleIoc.Default.Register<B>();
}
public A a {
get { return ServiceLocator.Current.GetInstance<A>(); }
}
public B b {
get
{
return ServiceLocator.Current.GetInstance<B>();
}
}
After updating data from A, I want to open B and i do it in the following way:
private void A_Button_Click(object sender, RoutedEventArgs e)
{
var bWindow = new bView();
bWindow.Show();
this.Close();
}
This works, but B uses data from A, and the updated data is not shown until I close my program and open it again. I've read that it has something to do with the Viewmodellocator and messages but as I am rather new to this, I don't exactly now how and/or where I need to do some "cleaning up".
Can anyone please help me with this? Thanks in advance.
hopefully you can help me. First of all, let me explain what my problem is.
I have two ViewModels. The first one has e.g. stored information in several textboxes.
For example
private static string _tbxCfgLogfile;
public string TbxCfgLogfile
{
get { return _tbxCfgLogfile; }
set
{
_tbxCfgLogfile = value;
NotifyOfPropertyChange(() => TbxCfgLogfile);
}
}
The other ViewModel has a Button where i want to save this data from the textboxes.
It does look like this
public bool CanBtnCfgSave
{
get
{
return (new PageConfigGeneralViewModel().TbxCfgLogfile.Length > 0 [...]);
}
}
public void BtnCfgSave()
{
new Functions.Config().SaveConfig();
}
How can i let "CanBtnCfgSave" know that the condition is met or not?
My first try was
private static string _tbxCfgLogfile;
public string TbxCfgLogfile
{
get { return _tbxCfgLogfile; }
set
{
_tbxCfgLogfile = value;
NotifyOfPropertyChange(() => TbxCfgLogfile);
NotifyOfPropertyChange(() => new ViewModels.OtherViewModel.CanBtnCfgSave);
}
}
It does not work. When i do remember right, i can get the data from each ViewModel, but i cannot set nor Notify them without any effort. Is that right? Do i have to use an "Event Aggregator" to accomplish my goal or is there an alternative easier way?
Not sure what you are doing in your viewmodels - why are you instantiating viewmodels in property accessors?
What is this line doing?
return (new PageConfigGeneralViewModel().TbxCfgLogfile.Length > 0 [...]);
I can't be sure from your setup as you haven't mentioned much about the architecture, but sincce you should have an instance of each viewmodel, there must be something conducting/managing the two (or one managing the other)
If you have one managing the other and you are implementing this via concrete references, you can just pick up the fields from the other viewmodel by accessing the properties directly, and hooking the PropertyChanged event of the child to notify the parent
class ParentViewModel : PropertyChangedBase
{
ChildViewModel childVM;
public ParentViewModel()
{
// Create child VM and hook up event...
childVM = new ChildViewModel();
childVM.PropertyChanged = ChildViewModel_PropertyChanged;
}
void ChildViewModel_PropertyChanged(object sender, System.ComponentModel.PropertyChangedEventArgs e)
{
// When any properties on the child VM change, update CanSave
NotifyOfPropertyChange(() => CanSave);
}
// Look at properties on the child VM
public bool CanSave { get { return childVM.SomeProperty != string.Empty; } }
public void Save() { // do stuff }
}
class ChildViewModel : PropertyChangedBase
{
private static string _someProperty;
public string SomeProperty
{
get { return _someProperty; }
set
{
_someProperty = value;
NotifyOfPropertyChange(() => SomeProperty);
}
}
}
Of course this is a very direct way to do it - you could just create a binding to CanSave on the child VM if that works, saving the need to create the CanSave property on the parent
Are there any events that Visual Studio raises while debugging that I could subscribe to in the code? Specifically, I'd like to know when a debugger is detached or stops. Thanks
In a separate thread you could check the Debugger.IsAttached method and generate events accordingly.
EDIT: I just whipped this up, see if it works.
public class DebuggerEvents {
public delegate void DebuggingStatusChanged(EventArgs e);
public event DebuggingStatusChanged DebuggerAttached;
public event DebuggingStatusChanged DebuggerUnattached;
private readonly Thread workerThread;
public DebuggerEvents() {
var threadStart = new ThreadStart(BackgoundWorker);
workerThread = new Thread(threadStart);
workerThread.Start();
}
private void BackgoundWorker() {
bool currentStateflag = Debugger.IsAttached;
while (true) {
if (Debugger.IsAttached && !currentStateflag){
DebuggerAttached(new EventArgs());
currentStateflag = true;
}
if (!Debugger.IsAttached && currentStateflag){
DebuggerUnattached(new EventArgs());
currentStateflag = false;
}
Thread.Sleep(100);
}
}
}
Try this:
System.Diagnostics.Debugger.IsAttached
Also look up conditional compilation symbols and pay attention to the DEBUG symbol.