Generic list's items are all the same
0
Im populating a List with my object (Event).
The object has a field called DocumentDate that is what I wish to update in each item.
But after the loop, all items in the list are the same! I want to know why:
The code:
private List<Events> CreateEventsBetween(string start, string end, string repeatState, Event defaultEvent)
{
var states = Resources.GetStringArray(Resource.Array.repeat_states);
DateTime.TryParse(start, out DateTime dtStart);
DateTime.TryParse(end, out DateTime dtEnd);
List<Event> events = new List<Event>();
if (repeatState == states[0])
while(dtStart<= dtEnd)
{
var e = defaultEvent;
e.DocumentDate = dtStart;
events.Add(e);
dtStart= dtStart.AddDays(i);
}
...
...
...
return events;
}
Here every item in the list of events have the same DocumentDate's, when they should have different ones
c# list loops
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
add a comment |
0
Im populating a List with my object (Event).
The object has a field called DocumentDate that is what I wish to update in each item.
But after the loop, all items in the list are the same! I want to know why:
The code:
private List<Events> CreateEventsBetween(string start, string end, string repeatState, Event defaultEvent)
{
var states = Resources.GetStringArray(Resource.Array.repeat_states);
DateTime.TryParse(start, out DateTime dtStart);
DateTime.TryParse(end, out DateTime dtEnd);
List<Event> events = new List<Event>();
if (repeatState == states[0])
while(dtStart<= dtEnd)
{
var e = defaultEvent;
e.DocumentDate = dtStart;
events.Add(e);
dtStart= dtStart.AddDays(i);
}
...
...
...
return events;
}
Here every item in the list of events have the same DocumentDate's, when they should have different ones
c# list loops
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
Instead of the while loop, you could also assign the events in a single line usingSystem.Linq, for example:var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();
– Rufus L
Nov 15 '18 at 17:24
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49
add a comment |
0
0
0
Im populating a List with my object (Event).
The object has a field called DocumentDate that is what I wish to update in each item.
But after the loop, all items in the list are the same! I want to know why:
The code:
private List<Events> CreateEventsBetween(string start, string end, string repeatState, Event defaultEvent)
{
var states = Resources.GetStringArray(Resource.Array.repeat_states);
DateTime.TryParse(start, out DateTime dtStart);
DateTime.TryParse(end, out DateTime dtEnd);
List<Event> events = new List<Event>();
if (repeatState == states[0])
while(dtStart<= dtEnd)
{
var e = defaultEvent;
e.DocumentDate = dtStart;
events.Add(e);
dtStart= dtStart.AddDays(i);
}
...
...
...
return events;
}
Here every item in the list of events have the same DocumentDate's, when they should have different ones
c# list loops
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
Im populating a List with my object (Event).
The object has a field called DocumentDate that is what I wish to update in each item.
But after the loop, all items in the list are the same! I want to know why:
The code:
private List<Events> CreateEventsBetween(string start, string end, string repeatState, Event defaultEvent)
{
var states = Resources.GetStringArray(Resource.Array.repeat_states);
DateTime.TryParse(start, out DateTime dtStart);
DateTime.TryParse(end, out DateTime dtEnd);
List<Event> events = new List<Event>();
if (repeatState == states[0])
while(dtStart<= dtEnd)
{
var e = defaultEvent;
e.DocumentDate = dtStart;
events.Add(e);
dtStart= dtStart.AddDays(i);
}
...
...
...
return events;
}
Here every item in the list of events have the same DocumentDate's, when they should have different ones
c# list loops
c# list loops
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
edited Nov 16 '18 at 12:28
Erick Santander
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
asked Nov 15 '18 at 16:56
Erick SantanderErick Santander
5911
5911
Instead of the while loop, you could also assign the events in a single line usingSystem.Linq, for example:var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();
– Rufus L
Nov 15 '18 at 17:24
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49
add a comment |
Instead of the while loop, you could also assign the events in a single line usingSystem.Linq, for example:var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();
– Rufus L
Nov 15 '18 at 17:24
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49
Instead of the while loop, you could also assign the events in a single line using
System.Linq, for example: var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();– Rufus L
Nov 15 '18 at 17:24
Instead of the while loop, you could also assign the events in a single line using
System.Linq, for example: var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();– Rufus L
Nov 15 '18 at 17:24
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49
add a comment |
1 Answer
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Because all events are the same reference. You assign it at var e = defaultEvent;.
Instead you need to initialize different with new:
var e = new Event{ DocumentDate = dtStart }; // other properties as well
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
add a comment |
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Because all events are the same reference. You assign it at var e = defaultEvent;.
Instead you need to initialize different with new:
var e = new Event{ DocumentDate = dtStart }; // other properties as well
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
add a comment |
2
Because all events are the same reference. You assign it at var e = defaultEvent;.
Instead you need to initialize different with new:
var e = new Event{ DocumentDate = dtStart }; // other properties as well
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
add a comment |
2
2
2
Because all events are the same reference. You assign it at var e = defaultEvent;.
Instead you need to initialize different with new:
var e = new Event{ DocumentDate = dtStart }; // other properties as well
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
Because all events are the same reference. You assign it at var e = defaultEvent;.
Instead you need to initialize different with new:
var e = new Event{ DocumentDate = dtStart }; // other properties as well
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
edited Nov 16 '18 at 12:51
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
answered Nov 15 '18 at 16:58
RangoRango
365k46472730
365k46472730
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
add a comment |
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
the date aux was supposed to be dtStart, sorry, I was translating the code to put it in here, and forgot to change that, thanks. I was suspicious about the defaultEvent, but since I changed the date I thought it would mater, anyways, thanks again!
– Erick Santander
Nov 15 '18 at 17:16
add a comment |
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Instead of the while loop, you could also assign the events in a single line using
System.Linq, for example:var events = Enumerable.Range(0, dtEnd.Subtract(dtStart).Days).Select(i => new Event {DocumentDate = dtStart.AddDays(i)}).ToList();– Rufus L
Nov 15 '18 at 17:24
Sorry, I corrected the generic List thing, now, I don't think that would do for me, my object has other fields (about 24 or so), and I need the other fields to be equal to the defaultEvent, just changing the DocumentDate.
– Erick Santander
Nov 16 '18 at 12:32
In that case you may need to implement a deep copy method on your class if the goal is to allow callers of this method to define their own default property values. That way you can create a new instance based on the one passed in. this question has answers that describe how to implement a deep clone method on a class.
– Rufus L
Nov 16 '18 at 16:49