I want to say that my code works correctly but i don't know why it is working like that. So to make it clear, here is my code:
List<NewsFlash> newsfl = tsm.getNewsFlashes();
foreach (NewsFlash item in newsfl)
{
item.smartform.dtDate = item.smartform.dtDate.ToShortDateString();
}
//Get all the newsFlash items and bind to the repeater
rptNewsFlash.DataSource = newsfl;
rptNewsFlash.DataBind();
Like you can see, I am looping the list newsfl and I am editing item.smartform.dtDate. What is weird for me is, when I edit item.smartform.dtDate, then the property dtDate in the list newsfl is also changed. This is what I want, but it is kind of weird I think, because item within the foreach loop has nothing to do with the list newsfl?
Hope you understand my question.
Thanks
Each item in the foreach is just a reference to the item at a specific index within newsfl - so when your loop is done, you've updated all the item's in the list, and those items hang onto those changes. This makes sense because each item is not a copy of the original, it is the original.
So, imagine item and newsfl[n] as two doors to the same room, you end up in the same place - and it doesn't matter which door I arrive through, if I start moving furniture around, it is also moved for anyone who comes in through either door.
On another note, if this didn't happen, then what would you expect to happen? Since you make changes to item, surely you want to keep them?
In the line foreach (NewsFlash item in newsfl) you take a reference, called item, to each of the entries in newsfl. This doesn't create a copy of the item, just a reference to the item in the list.
That way if you update a value on item, the entry in newfl will also be updated.
Why shouldn't it be changed? The object "item" in your foreach loop is exactly the same object as the one in your "newsfl" list. Actually the object "item" only points to the correct object in the list.
Related
I am currently working on a rogue-like game in GameMaker Studio 2 and i would like to have an item spawner where no items are repeated.
I have tried multiple different ideas of what i think would work, such as giving items and id variable and only spawning items which hasn't had it's id called, although it doesn't seem to work.
The code I have right now is basic, but that is because it's the only way I've been able to spawn an item, there is repeating items with what i have and i would like to stop that from happening.
Here is the Create code of the object:
// Items
var items = choose(
obj_homing,
obj_tracking,
obj_bounce,
obj_double_xp,
obj_shotgun,
obj_orbit,
obj_firefaster,
obj_scattershot,
obj_damageboost,
obj_explosive
);
instance_create_layer(x, y, "Items", choose(items));
I haven't had any actually crashes in the game, although the errors i have faced are multiple of the same object spawning twice when i would like items to not repeat.
One option is to modify the items array after each call to remove the spawned item, and re-initialize it as full only at the start of each game or when the array is empty.
The problem I'm seeing in looking through the Game Maker Language Documentation is that I cannot find a way to delete an object from an existing array and resize the array.
You're placing choose on both defining the var, and when creating the layer.
Now, I don't know exactly what choose does, but I assume it's choosing randomly a selection from the array.
So Items would only return a single chosen item from the array, maybe it's better to remove the choose function from the Items, and only decide that when creating the object.
So the Items should become an array:
var items = [
obj_homing,
obj_tracking,
obj_bounce,
obj_double_xp,
obj_shotgun,
obj_orbit,
obj_firefaster,
obj_scattershot,
obj_damageboost,
obj_explosive
];
Just save the random instance in a variable, then when you create a random instance, check if equals to the instance that you have created previously, and if it is, call again the function until the previous instance is different from the new generated instance.
If you want to spawn every item only once, how about changing the current spawned object in the array to "noone".
And at every spawn cycle, you would check, if the selected item is noone and if so, select the next item (array[i++]).
Also do not forget to randomize the seed, somewhere in the beginning of your game with randomize().
I'm in need of a little help in here . I'm getting results that come from virtual property , but one row displays in multiple rows in view. How to display a record inside a row , and not in multiple records
#foreach (var item in Model.Event.Id)
appears to be your problem. You're looping over the event ID, which since it's a string, will be treated like an array of characters. Therefore it prints one character from the ID on each line, and then, because of the rest of the code, repeats all the other details of that event on each line.
Since you only appear to have one single Event in your Model, it seems that you do not need any kind of loop here at all.
However it's not entirely clear what your intentions are - perhaps you intended to loop over something else in your model which is not shown. If so, please clarify the question and possibly the answer could be expanded.
We have a hierarchical watch app.
The root controller is a table of menu items. That list of items is controlled by a server. The data is retrieved and stored in core data. The menu is populated the first time going into the app.
But I want this table to stay current. My thought was to add code to willActivate to check if there was changes, and reload the table. In my reload logic I call the same function I called the first time, which sets the menuTable.setNumberOfRows and creates each row. Looking at what I'm putting in the logs, it is going through this logic with a different count of rows and new labels. But the app on the watch shows the table with the old data.
How can I get this table to reload with the new information?
I've had this problem too and as rmp says, it still seems to be a bug in watchOS 1.0.1. The problem appears when you try to reload your tableView after run willActivate() and nothing will happen.
In my case, I reload the tableView after receive a reply from a delegate and then I reload all the content just if it's necessary. To achieve this, I remove all rows from a NSIndexSet and load again.
if isNecessary {
self.table.removeRowsAtIndexes(NSIndexSet(indexesInRange: NSMakeRange(0, maxItems)))
isNecessary = false
}
I've tried a lot of tricks but none has worked for me:
Force to reload rows by table.setNumberOfRows(0, withRowType: "data")
Setting parameters to empty text before assign new values
One thing you could do is to hide tableView before removing rows, and avoid the remove animation.
It is a bug in WatchKit. Seems like Apple doesn't handle the repetitive interface object correctly.
The general principle here is: Only insert or remove necessary rows after a table is created. Do not reload the whole table like what we usually do in iOS. It just doesn't work (or trigger the bug).
So specifically, you have to:
Do this in willActivated method. This is correct.
If this is the first load, before the table is even created, do what you are now doing – load all table rows.
For all following times, don't reload the table, fetch the new data and check the desired number of rows.
Compare with the current number of rows in the table, insert to or remove from the bottom of the existing table.
Now simply re-assign the new data to all existing rows. Again, do not reload.
It should work if you follow the above steps.
I have found what works best given the current state of watchkit is to remove all rows then re-populate the table.
Try something like this:
- (void)loadTableData{
//clear the table
[mainTableView setNumberOfRows:0 withRowType:#"myTableRow"];
//set the row count again
[mainTableView setNumberOfRows:numberOfRows withRowType:#"myTableRow"];
//populate table
}
Its pretty simple. As Apple hasn't provided any method to reload the data.
You can still achieve that by simply populating the rows for the tableview.
Below is the sample code:
for index in 0..<tracksTableView.numberOfRows {
if let controller = tracksTableView.rowController(at: index) as? EditPlaylistRowController {
controller.playingTrackId = self.playingTrackID
controller.sharedTrack = trackItems[index]
}
}
Use it whenever you want to refresh the data.
NOTE:
You can still make some conditional statements inside the row controller class.
Happy to help :)
I have a simple list in Flex that is populated every N seconds by a dataprovider. My goal is to avoid scrolling the list after the dataprovider has been changed.
So, before I populate the list, I save the selectedIndex, and once the dataProvider is filled, I call:
list.selectedIndex = index;
list.scrollToIndex(index);
Trouble is that this moves the selected item of the list to the top.
The solution would be to get the index of the first element displayed in the list: but I have no idea on how to get that. Any clue?
Perhaps something like: list.getIndexFirstVisibleElement()
You haven't mentioned if you're using Flex 4, but if you are you might want to look into ensureIndexIsVisible.
You can find an example here: http://blog.flexexamples.com/2010/05/12/scrolling-to-a-specific-index-in-a-spark-list-control-in-flex-4/.
I have a problem with the AdvancedDataGrid widget. When the dataProvider is an ArrayCollection (of arrays), the nth array (within the collection) is also the nth row within the grid, and I can jump and display the i-th row by scripting
adg.selectedIndex = i;
adg.scrollToIndex(i);
now, when I add a Grouping, the dataProvider ends up being a GroupingCollection2, and now the index in the dataprovider's source does not correspond to the index in the adg anymore (which is understandable, because it's being grouped).
How can I select and display a row in grouped data efficiently? Currently, I have to traverse the adg and compare each found item with its data attributes in order to find the correct index of the row within the adg, and jump to it like above. This process is very slow. Any thoughts?
edited later:
We already used a caching object as Shaun suggests, but it still didn't compensate for the search times. In order to fully construct a sorting of a list of things (which this problem equates to, as the list is completely reordered by the grouping), you always have to know the entire set. In the end we didn't solve that problem. The project is over now. I will accept Shaun's answer if no one knows a better way in three days.
Depending on what values your comparing against you can store the objects in a dictionary with the lookup using the property/properties that would be searched for, this way you have a constant time look-up for the object (no need to look at every single item). Say for example your using a property called id on an object then you can create an AS object like
var idLookup:Object = {};
for(myObject in objects)
idLookup[myObject.id] = myObject;
//Say you want multiple properties
//idLookup[myObject.id]={};
//idLookup[myObject.id][myObject.otherProp] = myObject;
now say the user types in an id you go into the idLookup object at that id property and retrieve the object:
var myObject:Object = idLookup[userInput.text];
myAdg.expandItem(myObject, true);
now when you want to get an object by id you can just do
http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/mx/controls/AdvancedDataGrid.html#expandItem()
I haven't done any thorough testing of this directly, but use a similar concept for doing quick look-ups for advanced filtering. Let me know if this helps at all or is going in the wrong direction. Also if you could clarify a bit more in terms of what types/number of values you need to lookup and if there's the possibility for multiple matches etc. I may be able to provide a better answer.
Good luck,
Shaun