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dotnet windows forms
group:Fast Searches of a Thread Safe Collection of Structs
dotnet windows forms:
of which contains a bunch of properties describing a person (e.g., LastName, FirstName, EmployeeID, HomeAddress, ZipCode, etc). So each instance of the struct will describe a person - and about 900 instances (people) will be contained in the collection. Users must be able to search for a specific person by any of the properties (e.g., LastName, FirstName, EmployeeID, HomeAddress, ZipCode, etc). So the collection must be searchable by all of the properties of the contained struct instances. Please note that the comparison will be between (1) a string the user is typing into a textbox, and (2) the specified property (e.g., LastName) -- such that AS the user types, a list displayed elsewhere on the form will dynamically show ALL of the closest matches (closest to the string the user is typing AS the user types). The collection will periodically be updated on a background thread (every 15 or so minutes) - so the collection must be "thread safe." MY QUESTIONS: 1. How do I make the collection of structs searchable by *each* of its properties (LastName, FirstName, Zip, etc...). Of course only one property at a time would be searched on. I would think implementing IComparable would work - but apparently doing so would let me enable searching on only one of the properties (but I need to enable searching on ALL of the properties). 2. How do I make the collection "thread safe" so that the collection can be updated by a background thread while users may be searching for a person in the collection. Note: people [in the collection] will almost never be deleted - so phantom matches are not really a concern. Just looking for high-level direction on this. Thank you very much!
Thanks William... can you expand just a bit? I'm not clear on [... Predicate
delegates... ]. -Jeff [quoted text, click to view] "William Stacey [MVP]" <william.stacey@gmail.com> wrote in message news:uaLv6TvUGHA.5496@TK2MSFTNGP11.phx.gbl... > Lock the list during reads and writes. Use List<struct> and Find() using > different Predicate delegates for your different search needs. > > -- > William Stacey [MVP] > > "Jeff S." <A@B.COM> wrote in message > news:%231y7IKvUGHA.5500@TK2MSFTNGP12.phx.gbl... > | In a Windows Forms application I plan to have a collection of structs - > each > | of which contains a bunch of properties describing a person (e.g., > LastName, > | FirstName, EmployeeID, HomeAddress, ZipCode, etc). So each instance of > the > | struct will describe a person - and about 900 instances (people) will be > | contained in the collection. > | > | Users must be able to search for a specific person by any of the > properties > | (e.g., LastName, FirstName, EmployeeID, HomeAddress, ZipCode, etc). So > the > | collection must be searchable by all of the properties of the contained > | struct instances. > | > | Please note that the comparison will be between (1) a string the user is > | typing into a textbox, and (2) the specified property (e.g., > LastName) -- > | such that AS the user types, a list displayed elsewhere on the form will > | dynamically show ALL of the closest matches (closest to the string the > user > | is typing AS the user types). > | > | The collection will periodically be updated on a background thread > (every > 15 > | or so minutes) - so the collection must be "thread safe." > | > | MY QUESTIONS: > | 1. How do I make the collection of structs searchable by *each* of its > | properties (LastName, FirstName, Zip, etc...). Of course only one > property > | at a time would be searched on. I would think implementing IComparable > would > | work - but apparently doing so would let me enable searching on only one > of > | the properties (but I need to enable searching on ALL of the > properties). > | > | 2. How do I make the collection "thread safe" so that the collection can > be > | updated by a background thread while users may be searching for a person > in > | the collection. Note: people [in the collection] will almost never be > | deleted - so phantom matches are not really a concern. > | > | Just looking for high-level direction on this. > | > | Thank you very much! > | > | > | > | > >
[quoted text, click to view]
Jeff S. <A@B.COM> wrote: > Thanks William... can you expand just a bit? I'm not clear on [... Predicate > delegates... ]. Just to check before too much detail is gone into - are you using .NET 2.0 or 1.1? You won't be able to use List<T> if you're only using 1.1. Also, do you *have* to use structs? Why are you using structs rather than classes? -- Jon Skeet - <skeet@pobox.com> http://www.pobox.com/~skeet Blog: http://www.msmvps.com/jon.skeet
And you almost certainly shouldn't be using use structs for a Person class.
Your post talks about the string that the person is "typing" into a box - this sounds like an incremental search to me - if so you would need to sort the list for the particular property instead of using predicates. [quoted text, click to view] "William Stacey [MVP]" <william.stacey@gmail.com> wrote in message news:uaLv6TvUGHA.5496@TK2MSFTNGP11.phx.gbl... > Lock the list during reads and writes. Use List<struct> and Find() using > different Predicate delegates for your different search needs. > > -- > William Stacey [MVP] > > "Jeff S." <A@B.COM> wrote in message > news:%231y7IKvUGHA.5500@TK2MSFTNGP12.phx.gbl... > | In a Windows Forms application I plan to have a collection of structs - > each > | of which contains a bunch of properties describing a person (e.g., > LastName, > | FirstName, EmployeeID, HomeAddress, ZipCode, etc). So each instance of > the > | struct will describe a person - and about 900 instances (people) will be > | contained in the collection. > | > | Users must be able to search for a specific person by any of the > properties > | (e.g., LastName, FirstName, EmployeeID, HomeAddress, ZipCode, etc). So > the > | collection must be searchable by all of the properties of the contained > | struct instances. > | > | Please note that the comparison will be between (1) a string the user is > | typing into a textbox, and (2) the specified property (e.g., > LastName) -- > | such that AS the user types, a list displayed elsewhere on the form will > | dynamically show ALL of the closest matches (closest to the string the > user > | is typing AS the user types). > | > | The collection will periodically be updated on a background thread > (every > 15 > | or so minutes) - so the collection must be "thread safe." > | > | MY QUESTIONS: > | 1. How do I make the collection of structs searchable by *each* of its > | properties (LastName, FirstName, Zip, etc...). Of course only one > property > | at a time would be searched on. I would think implementing IComparable > would > | work - but apparently doing so would let me enable searching on only one > of > | the properties (but I need to enable searching on ALL of the > properties). > | > | 2. How do I make the collection "thread safe" so that the collection can > be > | updated by a background thread while users may be searching for a person > in > | the collection. Note: people [in the collection] will almost never be > | deleted - so phantom matches are not really a concern. > | > | Just looking for high-level direction on this. > | > | Thank you very much! > | > | > | > | > >
Lock the list during reads and writes. Use List<struct> and Find() using
different Predicate delegates for your different search needs. -- William Stacey [MVP] [quoted text, click to view] "Jeff S." <A@B.COM> wrote in message | In a Windows Forms application I plan to have a collection of structs - news:%231y7IKvUGHA.5500@TK2MSFTNGP12.phx.gbl... each | of which contains a bunch of properties describing a person (e.g., LastName, | FirstName, EmployeeID, HomeAddress, ZipCode, etc). So each instance of the | struct will describe a person - and about 900 instances (people) will be | contained in the collection. | | Users must be able to search for a specific person by any of the properties | (e.g., LastName, FirstName, EmployeeID, HomeAddress, ZipCode, etc). So the | collection must be searchable by all of the properties of the contained | struct instances. | | Please note that the comparison will be between (1) a string the user is | typing into a textbox, and (2) the specified property (e.g., LastName) -- | such that AS the user types, a list displayed elsewhere on the form will | dynamically show ALL of the closest matches (closest to the string the user | is typing AS the user types). | | The collection will periodically be updated on a background thread (every 15 | or so minutes) - so the collection must be "thread safe." | | MY QUESTIONS: | 1. How do I make the collection of structs searchable by *each* of its | properties (LastName, FirstName, Zip, etc...). Of course only one property | at a time would be searched on. I would think implementing IComparable would | work - but apparently doing so would let me enable searching on only one of | the properties (but I need to enable searching on ALL of the properties). | | 2. How do I make the collection "thread safe" so that the collection can be | updated by a background thread while users may be searching for a person in | the collection. Note: people [in the collection] will almost never be | deleted - so phantom matches are not really a concern. | | Just looking for high-level direction on this. | | Thank you very much! | | | |
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