With the || Operator, Microsoft describes short circuit evaluation here Short Circuit Evaluation
However, I have the following code which seems to contradict this process:
if ((_opcLoaded || DoLoadOPC()) &&
(_tagsAdded || DoAddTags()) &&
DoWriteRecipe() &&
(DoResume()))
What I'm trying to prevent is the function DoAddTags from being called if _tagsAdded is true (DoAddTags sets _tagsAdded to true).
However, I'm finding that DoAddTags is called even when _tagsAdded is true. It's the same for _opcLoaded and DoLoadOPC. I've had to put a condition inside DoAddTags to check for _tagsAdded, which shouldn't be necessary.
Can someone explain why this is happening?
Here is the Complete Code
//
// Resume a Paused recipe
case MonitoredTasks.Resume:
Task.Factory.StartNew(() =>
{
MonitoredTask = MonitoredTasks.None;
if ((_opcLoaded || DoLoadOPC()) &&
**(_tagsAdded || DoAddTags())** &&
DoWriteRecipe() &&
(DoResume()))
{
MonitoredTask = MonitoredTasks.None;
RunningState = RecipeRunningStates.Running;
Status = CIPStatuses.Running;
}
else
{
MonitoredTask = MonitoredTasks.Resume;
}
});
break;
And the code for DoAddTags
/// <summary>
/// Adds all necessary tags to the OPC Server Manager
/// </summary>
/// <returns></returns>
bool DoAddTags()
{
bool result = false;
var oldActivity = Activity;
//
// Not doing anything OPC related?
if (Activity != CIPActivities.AddingOPCTags && !_tagsAdded && Activity != CIPActivities.StartingOPC)
{
lock (_locks[LOCK_OPC])
{
Activity = CIPActivities.AddingOPCTags;
Status = CIPStatuses.Initialising;
RecipeError = Errors.None;
try
{
//
// Reset connection and internal tags list
_serverManager.Reset();
//
// Now to add all OPC Tags - Area
CIPStatusTag = _serverManager.AddTag(_area.CIPStatusTag);
RecipeIDTag = _serverManager.AddTag(_area.RecipeIDTag);
RecipeInstructionIDTag = _serverManager.AddTag(_area.RecipeInstructionIDTag);
HandshakingTag = _serverManager.AddTag(_area.HandshakingTag);
GlobalInstructionIDTag = _serverManager.AddTag(_area.GlobalInstructionIDTag);
InstructionAttemptsTag = _serverManager.AddTag(_area.InstructionAttemptsTag);
//
// Area tags OK?
if (CIPStatusTag == null || RecipeIDTag == null || RecipeInstructionIDTag == null || HandshakingTag == null || GlobalInstructionIDTag == null || InstructionAttemptsTag == null)
{
RecipeError = Errors.InvalidAreaTags;
DoError(new RecipeErrorHandlerEventArgs(this) { Message = FormatMessage("CIPRecipe.DoAddTags - Invalid AREA Tags"), Sender = this });
}
else
{
VM_CIPInstruction vm = null;
bool instructionTagErrors = false;
//
// For each area instruction that is used, assig a link to the instruction
foreach (var i in _areaInstructions)
{
//
// Create a View Model for the specified area instruction : this allows us to determine the number of parameters (tags) that apply to the instruction
vm = new VM_CIPInstruction(i.Value.Instruction);
//
// Assign device reference tags
if (vm.DeviceReferencesAvailable)
{
i.Value.DeviceTag = _serverManager.AddTag(i.Value.Instruction.DeviceReferenceTag);
instructionTagErrors = i.Value.DeviceTag == null;
}
//
// For each required parameter, add tag
for (int paramNo = 1; paramNo <= vm.NoOfParams; paramNo++)
{
switch (paramNo)
{
case 1:
//
// Tag defined? Add it
if (vm.AreaInstruction.Param1Tag >= 0)
{
i.Value.Param1 = _serverManager.AddTag(i.Value.Instruction.Param1Tag);
if (i.Value.Param1 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
case 2:
//
// Tag defined? Add it
if (vm.AreaInstruction.Param2Tag >= 0)
{
i.Value.Param2 = _serverManager.AddTag(i.Value.Instruction.Param2Tag);
if (i.Value.Param2 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
case 3:
//
// Tag defined? Add it
if (vm.AreaInstruction.Param3Tag >= 0)
{
i.Value.Param3 = _serverManager.AddTag(i.Value.Instruction.Param3Tag);
if (i.Value.Param3 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
case 4:
//
// Tag defined? Add it and then check quality
if (vm.AreaInstruction.Param4Tag >= 0)
{
i.Value.Param4 = _serverManager.AddTag(i.Value.Instruction.Param4Tag);
if (i.Value.Param4 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
case 5:
//
// Tag defined? Add it and then check quality
if (vm.AreaInstruction.Param5Tag >= 0)
{
i.Value.Param5 = _serverManager.AddTag(i.Value.Instruction.Param5Tag);
if (i.Value.Param5 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
case 6:
//
// Tag defined? Add it and then check quality
if (vm.AreaInstruction.Param6Tag >= 0)
{
i.Value.Param6 = _serverManager.AddTag(i.Value.Instruction.Param6Tag);
if (i.Value.Param6 == null)
{
instructionTagErrors = true;
}
}
else
{
instructionTagErrors = true;
}
break;
}
}
if (instructionTagErrors)
{
RecipeError = Errors.InvalidInstructionTags;
DoError(new RecipeErrorHandlerEventArgs(this) { Message = FormatMessage(String.Format("CIPRecipe.DoAddTags - Invalid Instruction {0} Tags", vm.Name)), Sender = this });
break;
}
}
//
// Any problems adding tags?
if (RecipeError == Errors.None)
{
Activity = CIPActivities.StartingOPC;
//
// Once all tags added, start OPC Server
result = _serverManager.Start();
if (!result)
{
Status = CIPStatuses.AddTagsFailed;
RecipeError = Errors.OPC;
DoError(new RecipeErrorHandlerEventArgs(this) { Message = FormatMessage("CIPRecipe.DoAddTags - Start of OPC failed"), Sender = this });
}
else
{
**_tagsAdded = true;**
Status = CIPStatuses.TagsAdded;
}
}
else
{
Status = CIPStatuses.AddTagsFailed;
}
}
}
catch (Exception ex)
{
RecipeError = Errors.Exception_AddTags;
DoError(new RecipeErrorHandlerEventArgs(this) { Message = FormatMessage("CIPRecipe.DoAddTags"), Exception = ex, Sender = this });
}
finally
{
Activity = oldActivity;
}
}
}
return Status == CIPStatuses.TagsAdded;
}
I've highlighted the relevant lines with **
On the first pass DoAddTags is executed and _tagsAdded set to TRUE- I've placed a breakpoint here, so I know it is being set. Shortly afterwards (with or without the former breakpoint) DoAddTags is again entered (on the first line) despite_doAddTags == true.
I've even set a breakpoint on the code "(_tagsAdded || DoAddTags())". _tagsAdded == true, yet DoAddTags is still entered.
So what I'm seeing is, and all the Watches/Debugging info is consistent with is that DoAddTags is being called whilst _tagsAdded == true
This code won't display the behavior you describe, the short-circuiting works just as described.
What actually happens: _tagsAdded is initially false, so DoAddTags() is called, which sets _tagsAdded to true.
Then the debugger kicks in, you inspect _tagsAdded and see it's true.
Instead step through your code using F11 and inspect or watch all relevant variables.
Related
I'm coding a trading system using C#.Most of my logic is if some conditions occur at the same time,enter buy.
But in some scenario,I need an exclude logic:if some conditions occur at the same time not buy.
I tried to set a variable named Falling1 = true; and set Falling1=false; while the not buy conditions occur at the same time.
And then in my buy logic I need Falling1=true;.
namespace NinjaTrader.NinjaScript.Strategies
{
public class JJcrossCode : Strategy
{
private bool Falling1;
protected override void OnStateChange()
{
if (State == State.SetDefaults)
{
Description = #"Enter the description for your new custom Strategy here.";
Name = "JJcrossCode";
Falling1 = true;
}
else if (State == State.Configure)
{
}
else if (State == State.DataLoaded)
{
SetProfitTarget(#"Short", CalculationMode.Ticks, 20);
}
}
protected override void OnBarUpdate()
{
if (BarsInProgress != 0)
return;
if (CurrentBars[0] < 7)
return;
// Set 1
if (Open[0] > Close[0] && High[0] < High[1] && Low[0] < Low[1])
{
Falling1 = false;
}
// Set 2
// 01-crossabovelower
if (((CrossAbove(JurbolBBmacd1.Macd, JurbolBBmacd1.BollingerLower, 3))
&& (RSI1.Avg[0] < 67)&& (Falling1=true)
{
EnterLong(Convert.ToInt32(Size), #"Long");
}
}
}
The issue is that it seems the system can't recognize && (Falling1=true) in // 01-crossabovelower,I guess there are some structure issues in my code.
you want
&& (Falling1==true)
The way you wrote it you are doing an assignment
I am currently working on a search for a website and I am stuck with a problem, which doesn't even seem that hard to solve. I'm just not able to figure the solution out myself.
Situation: In the current state of my search I can sort the events to dates (I can select October for instance and it will only show the events which happen during october), for categories (The events each have categories) and even search text. Now when I select october as a month and festival as a category, I get all events occuring in october AND all festivals. I want only the festivals which occur in october. Any ideas on how I could achieve this?
This is what I've got so far:
var validEvents = new List<Item>();
var allEvents = ((LinkField)this.controlItem.Fields["Event Container"]).TargetItem.Children.ToList(); // getting the events
if (this.ddlMonths.SelectedIndex != 0 || this.ddlCategories.SelectedIndex != 0 || this.searchQuery.Text != string.Empty)
{
foreach (var currentEvent in allEvents)
{
var isValid = false;
// 1. Check for months
if (this.ddlMonths.SelectedIndex != 0)
{
// .. validation if event should be displayed
if (startDate <= monthDates[1].Date && endDate >= monthDates[0].Date)
{
isValid = true;
}
}
// 2. Check for categories
if (this.ddlCategories.SelectedIndex != 0)
{
foreach (var eventCategory in ((MultilistField) currentEvent.Fields["Categories"]).GetItems())
{
if (eventCategory["Category"].ToLower() == this.ddlCategories.SelectedValue.ToLower())
{
isValid = true;
}
}
}
// 3. Check for search query
if (this.searchQuery.Text != string.Empty)
{
var searchText = this.searchQuery.Text;
if (currentEvent["Title"].Contains(searchText) || currentEvent["Text"].Contains(searchText))
{
isValid = true;
}
}
if (isValid)
{
validEvents.Add(currentEvent);
}
}
}
Using LINQ you can combine search conditions as follows
var allEvents = ...;
IEnumerable<Item> events = allEvents;
if (ddlMonths.SelectedIndex != 0)
events = events.Where(condition1);
if (ddlCategories.SelectedIndex != 0)
events = events.Where(condition2);
if (searchQuery.Text != string.Empty)
events = events.Where(condition3);
var validEvents = events.ToList();
I would put
var isValid = true;
in line 8, then if any of the conditions is NOT met set it to false. And also skip any following check if isValid is already false.
Hope it helps!
EDIT - Complete code:
var validEvents = new List<Item>();
var allEvents = ((LinkField)this.controlItem.Fields["Event Container"]).TargetItem.Children.ToList(); // getting the events
if (this.ddlMonths.SelectedIndex != 0 || this.ddlCategories.SelectedIndex != 0 || this.searchQuery.Text != string.Empty)
{
foreach (var currentEvent in allEvents)
{
var isValid = true;
// 1. Check for months
if (this.ddlMonths.SelectedIndex != 0)
{
// .. validation if event should be displayed
if (!(isValid && startDate <= monthDates[1].Date && endDate >= monthDates[0].Date))
{
isValid = false;
}
}
// 2. Check for categories
if (this.ddlCategories.SelectedIndex != 0)
{
foreach (var eventCategory in ((MultilistField) currentEvent.Fields["Categories"]).GetItems())
{
if (!(isValid && eventCategory["Category"].ToLower() == this.ddlCategories.SelectedValue.ToLower()))
{
isValid = false;
}
}
}
// 3. Check for search query
if (this.searchQuery.Text != string.Empty)
{
var searchText = this.searchQuery.Text;
if (!(isValid && currentEvent["Title"].Contains(searchText) || currentEvent["Text"].Contains(searchText)))
{
isValid = true;
}
}
if (isValid)
{
validEvents.Add(currentEvent);
}
}
}
i have a form with more than one NumericUpDown as controls to input answer. i want every input is true for an operation (multiplication, sum etc), NumericUpDown for that operation will be disable. i have used the code below (just for sum operation), but i think its not efficient because i have to make a method to check every operation.
private void IsSumTrue() {
if (add1 + add2 == sum.Value)
{
sum.Enabled = false;
}
}
private void IsDifferenceTrue()
{
if (add1 - add2 == difference.Value)
{
difference.Enabled = false;
}
}
private void IsProductTrue()
{
if (add1 * add2 == product.Value)
{
product.Enabled = false;
}
}
private void IsQuotientTrue()
{
if (add1 / add2 == quotient.Value)
{
quotient.Enabled = false;
}
}
anyone have idea how to make it more efficient with just a method for all operation?
below is my idea, but to check the value is true for every NumericUpDown i don't know how.
private void DisableIfValueIsTrue()
{
foreach(Control control in this.Controls)
{
NumericUpDown value = control as NumericUpDown;
// if(value [NEED HELP]
}
}
Considering your situtaion, you can set a tag for each NumericUpDown in design mode like this:
sum.Tag=1;
square.Tag=2;
etc
Then define some int variables:
int iSum=add1+add2;
int iSquare= //Whatever you want
etc
And finally loop through your controls this way:
foreach (NumericUpDown control in this.Controls.OfType<NumericUpDown>())
{
int intCondition = Convert.ToInt32(control.Tag) == 1
? iSum
: Convert.ToInt32(control.Tag) == 2
? iSquare
: Convert.ToInt32(control.Tag) == 3
? i3
: i4; //You should extend this for your 8 controls
control.Enabled = intCondition == control.Value;
}
OK! Second way I offer
Since you will have to always check 8 different conditions, you could simply forget about looping through the controls and just change your method like this:
private void DisableIfValueIsTrue()
{
sum.Enabled = add1 + add2 != sum.Value;
difference.Enabled= add1 - add2 != difference.Value;
product.Enabled= add1 * add2 != product.Value;
quotient.Enabled= (add2 !=0) && (add1 / add2 != quotient.Value);
//etc
}
I came across this while doing some research and would like to give my solution I used for my situation and hope it helps people. I needed minimum and maximum numbers for a calculation, so mine are named appropriately and I correlated these with some CheckBoxes. I used null in beginning of minimum and end of maximum to account for empty. I also had to create an event handler SubscribeToEvents() shown below.
In my load event for my form:
SubscribeToEvents();
_checkBoxs = new[] { cbXLight, cbLight, cbMedium, cbHeavy, cbXHeavy, cbXXHeavy, cbXXXHeavy };
_minimumsNumericUpDowns = new[] { null, nLightMin, nMediumMin, nHeavyMin, nXHeavyMin, nXXHeavyMin, nXXXHeavyMin };
_maximumsNumericUpDowns = new[] { nXLightMax, nLightMax, nMediumMax, nHeavyMax, nXHeavyMax, nXXHeavyMax, null };
then I created a method:
private void DisableNumericUpDowns()
{
// disable everything:
foreach (var n in _minimumsNumericUpDowns)
{
if (n != null)
n.Enabled = false;
}
foreach (var n in _maximumsNumericUpDowns)
{
if (n != null)
n.Enabled = false;
}
}
The event handler:
private bool _eventsSubscribed;
private void SubscribeToEvents()
{
if (_eventsSubscribed)
return;
_eventsSubscribed = true;
cbXXHeavy.CheckedChanged += CheckBox_NumericState;
cbXHeavy.CheckedChanged += CheckBox_NumericState;
cbXLight.CheckedChanged += CheckBox_NumericState;
cbHeavy.CheckedChanged += CheckBox_NumericState;
cbLight.CheckedChanged += CheckBox_NumericState;
cbMedium.CheckedChanged += CheckBox_NumericState;
cbXXXHeavy.CheckedChanged += CheckBox_NumericState;
}
Now I can used this to check when they are enabled and if they are greater than or less than 0 if needed in the method CheckBox:
private void CheckBox_NumericState(object sender, EventArgs e)
{
// disable everything
DisableNumericUpDowns();
// see if more than one checkbox is checked:
var numChecked = _checkBoxs.Count((cb) => cb.Checked);
// enable things if more than one item is checked:
if (numChecked <= 1) return;
// find the smallest and enable its max:
var smallest = -1;
for (var i = 0; i < _checkBoxs.Length; i++)
{
if (!_checkBoxs[i].Checked) continue;
if (_maximumsNumericUpDowns[i] != null)
{
_maximumsNumericUpDowns[i].Enabled = true;
}
smallest = i;
break;
}
// find the largest and enable its min:
var largest = -1;
for (var i = _checkBoxs.Length - 1; i >= 0; i--)
{
if (!_checkBoxs[i].Checked) continue;
if (_minimumsNumericUpDowns[i] != null)
{
_minimumsNumericUpDowns[i].Enabled = true;
}
largest = i;
break;
}
// enable both for everything between smallest and largest:
var tempVar = largest - 1;
for (var i = (smallest + 1); i <= tempVar; i++)
{
if (!_checkBoxs[i].Checked) continue;
if (_minimumsNumericUpDowns[i] != null)
{
_minimumsNumericUpDowns[i].Enabled = true;
}
if (_maximumsNumericUpDowns[i] != null)
{
_maximumsNumericUpDowns[i].Enabled = true;
}
}
}
So I can check each state as required:
I want to check if Extra Light is check:
// Extra Light
if (!cbXLight.Checked) return;
if (nXLightMax.Enabled == false)
{
_structCategoryType = XLight;
CheckStructureSheets();
}
else
{
if (nXLightMax.Value > 0)
{
_dMax = nXLightMax.Value;
_structCategoryType = XLight;
CheckStructureSheets();
}
else
{
MessageBox.Show(#"Extra Light Max cannot be zero (0)");
}
}
and next light checks both:
// Light
if (cbLight.Checked)
{
if (nLightMin.Enabled == false && nLightMax.Enabled == false)
{
_structCategoryType = Light;
CheckStructureSheets();
}
else
{
if (nLightMin.Enabled && nLightMin.Value > 0)
{
if (nXLightMax.Enabled && nLightMin.Enabled && nLightMax.Enabled == false)
{
_dMin = nLightMin.Value;
_structCategoryType = Light;
CheckStructureSheets();
}
else
{
if (nLightMax.Value > 0)
{
_dMin = nLightMin.Value;
_dMax = nLightMax.Value;
_structCategoryType = Light;
CheckStructureSheets();
}
else
{
MessageBox.Show(#"Light Max cannot be zero (0)");
return;
}
}
}
else if (nLightMin.Enabled == false && nLightMax.Enabled)
{
if (nLightMax.Value > 0)
{
_dMax = nLightMax.Value;
_structCategoryType = Light;
CheckStructureSheets();
}
else
{
MessageBox.Show(#"Light Max cannot be zero (0)");
}
}
else
{
MessageBox.Show(#"Light Min cannot be zero (0)");
return;
}
}
}
Hope this helps someone.
Tim
thanks for #AlexJoliq and #BrettCaswell. just want to inform that before Alex edited his answer from using "==" to "!=", i (thought) already solved the problem. but i don't know where is the more effective and efficient way, alex's or mine.
below is my code for DisableIfValueIsTrue():
if (add1 + add2 == sum.Value) sum.Enabled = false;
if (add1 - add2 == difference.Value) difference.Enabled = false;
if (add1 * add2 == product.Value) product.Enabled = false;
if (add1 / add2 == quotient.Value) quotient.Enabled = false;
I'm trying to save a simple app setting ("LanguagePairId") this way:
if (rdbtnEnglishPersian.IsChecked == true) // because "IsChecked" is a nullable bool, the "== true" is necessary
{
langPairId = 1;
}
else if (rdbtnEnglishGerman.IsChecked == true)
{
langPairId = 2;
}
else if (rdbtnEnglishSpanish.IsChecked == true)
{
langPairId = 3;
}
else if (rdbtnGermanSpanish.IsChecked == true)
{
langPairId = 4;
}
else if (rdbtnGermanPersian.IsChecked == true)
{
langPairId = 5;
}
else if (rdbtnSpanishPersian.IsChecked == true)
{
langPairId = 6;
}
AppSettings.Default.LanguagePairId = langPairId;
LanguagePairId is being assigned the expected value (if rdbtnEnglishSpanish is checked, it is assigned 3, etc.)
But trying to read the app setting value on app startup:
int langPairId;
public MainWindow()
{
InitializeComponent();
RecheckTheLastSelectedRadBtn();
}
private void RecheckTheLastSelectedRadBtn()
{
langPairId = AppSettings.Default.LanguagePairId;
switch (langPairId)
{
case 1:
rdbtnEnglishPersian.IsChecked = true;
break;
. . .
...fails -- AppSettings.Default.LanguagePairId is seen as 0 on restaring the app. Why? What must I do to get the value to be saved and restored?
I don't see a call to AppSettings.Default.Save() anywhere.
Without that, your changes to the settings won't be saved.
Try adding it immediately after you set the property. E.g.:
AppSettings.Default.LanguagePairId = langPairId;
AppSettings.Default.Save();
This line of (C#) code
if (!currentLap.S1.HasValue)
is giving me
System.NullReferenceException: Object reference not set to an instance of an object.
provided I'm sure that currentLap variable is instantiated (because it's being used a few lines before and it is a local variable) and it has following property:
private double? _s1;
[DefaultValue(null)]
[JsonConverter(typeof(ShortDoubleConverter))]
public double? S1
{
get { return _s1; }
set { _s1 = value; }
}
how can it possibly throw NullReferenceException? Can it be something to do with optimization on Release mode?
Thanks,
Stevo
EDIT:
here is full method code.
public void Update(DriverData driverData)
{
LapInfo currentLap = this.CurrentLap;
if (currentLap != null &&
this.LastDriverData != null &&
driverData.TotalLaps != this.LastDriverData.TotalLaps &&
driverData.InPits &&
driverData.Speed < 10 &&
!this.LastDriverData.InPits)
{
currentLap.Escaped = true;
}
this.LastDriverData = driverData;
if ((currentLap == null || currentLap.Lap != driverData.LapNumber) &&
!this.Laps.TryGetValue(driverData.LapNumber, out currentLap))
{
currentLap = new LapInfo() { Lap = driverData.LapNumber, Parent = this, Class = driverData.Class };
this.Laps.Add(driverData.LapNumber, currentLap);
int lapsCount = 0, completedDriverLaps = 0, cleanLaps = 0;
this.TotalLaps = driverData.TotalLaps;
//if it's not the first lap
if (driverData.TotalLaps > 0)
{
//previous lap
if (this.CurrentLap == null || !this.CurrentLap.Escaped)
{
this.CompletedLaps++;
if (this.CurrentLap == null || !this.CurrentLap.MaxIncident.HasValue)
this.CleanLaps++;
}
}
foreach (DriverLapsInfo laps in this.Parent.LapsByVehicle.Values)
{
lapsCount += laps.TotalLaps;
completedDriverLaps += laps.CompletedLaps;
cleanLaps += laps.CleanLaps;
}
this.Parent.Parent.SetLapsCount(driverData, lapsCount, driverData.Class, completedDriverLaps, cleanLaps);
}
this.CurrentLap = currentLap;
//add incidents
if (driverData.Incidents != null)
{
foreach (IncidentScore incident in driverData.Incidents)
{
this.CurrentLap.MaxIncident = Math.Max(this.CurrentLap.MaxIncident ?? 0, incident.Strength);
this.CurrentLap.Incidents++;
this.Incidents++;
}
}
LapInfo previousLap = null;
if ((this.PreviousLap == null || this.PreviousLap.Lap != driverData.TotalLaps) &&
this.Laps.TryGetValue(driverData.TotalLaps, out previousLap))
{
this.PreviousLap = previousLap;
if (!this.PreviousLap.Date.HasValue)
{
this.PreviousLap.Date = DateTime.UtcNow;
}
}
if (currentLap.Position == 0)
currentLap.Position = driverData.Position;
if (driverData.CurrentS1 > 0)
{
**if (!currentLap.S1.HasValue)**
{
this.UpdateBestS1(driverData.BestS1);
this.Parent.Parent.UpdateBestS1(driverData.BestS1, driverData.UniqueName);
currentLap.UpdateS1(driverData.CurrentS1, driverData);
//reset the best split set at the finish line
if (this.PreviousLap != null && this.PreviousLap.SplitBest < 0)
this.PreviousLap.SplitBest = 0;
}
if (driverData.CurrentS2.HasValue && driverData.CurrentS1.HasValue && !currentLap.S2.HasValue)
{
double s2 = driverData.CurrentS2.Value - driverData.CurrentS1.Value;
this.UpdateBestS2(s2);
this.Parent.Parent.UpdateBestS2(s2, driverData.UniqueName);
currentLap.UpdateS2(s2, driverData);
}
}
if (this.PreviousLap != null)
{
if (driverData.LastLap > 0)
{
if (!this.PreviousLap.S3.HasValue && driverData.LastS2.HasValue)
{
double s3 = driverData.LastLap.Value - driverData.LastS2.Value;
this.UpdateBestS3(s3);
this.Parent.Parent.UpdateBestS3(s3, driverData.UniqueName);
this.PreviousLap.UpdateS3(s3, driverData);
}
if (!this.PreviousLap.LapTime.HasValue)
{
double? bestLap = this.Parent.Parent.BestLap;
this.PreviousLap.UpdateLapTime(driverData, 0);
this.Parent.Parent.UpdateBestLap(this.PreviousLap, driverData.BestLap, driverData);
this.UpdateBestLap(driverData.BestLap, this.PreviousLap);
this.PreviousLap.UpdateLapTime(driverData, bestLap);
}
}
else
{
if (this.PreviousLap.SplitBest.HasValue)
this.PreviousLap.UpdateBestSplit();
if (this.PreviousLap.SplitSelf.HasValue)
this.PreviousLap.UpdateSelfSplit();
}
}
if (driverData.InPits)
{
switch (driverData.Sector)
{
case Sectors.Sector1:
if (previousLap != null)
previousLap.InPits = true;
break;
case Sectors.Sector3:
currentLap.InPits = true;
break;
}
}
//lap to speed
if (currentLap.TopSpeed < driverData.Speed)
{
driverData.TopSpeedLap = driverData.Speed;
currentLap.UpdateTopSpeed(driverData.Speed);
}
else
driverData.TopSpeedLap = currentLap.TopSpeed;
//overall top speed
if (this.TopSpeed < driverData.Speed)
{
driverData.TopSpeed = driverData.Speed;
this.TopSpeed = driverData.Speed;
this.Parent.Parent.UpdateTopSpeed(this.TopSpeed, driverData);
}
else
driverData.TopSpeed = this.TopSpeed;
}
There is no way on earth the code can make it to that line and currentLap beeing null.
Or am I going crazy? :)
.HasValue will not throw if the nullable reference is null, but a.b.HasValue will if a is null.
I suspect that currentLap == null. I know you say you're sure that currentLap is not null, but I think that's the most likely explanation. Can you post more code?
Update:
Thanks for posting your code.
This doesn't throw:
void Main() {
var f = new Foo();
Console.WriteLine (f.S1);
Console.WriteLine (f.S1.HasValue);
}
class Foo {
private double? _s1 = null;
public double? S1 {
get { return _s1; }
set { _s1 = value; }
}
}
Could you try to create a minimal reproduction? (minimal code that exhibits the issue)
Maybe have a look at the previous line of code :) - debugger often highlights the next line after the one where the NullReferenceException was actually thrown.