tclientdataset

问题 I observed something last week that I did not expect, and will describe below. I am curious as to why this happens. Is it something internal to the TDataSet class, an artifact of the TDBGrid, or something else? The order of the fields in an open ClientDataSet changed. Specifically, I created a ClientDataSet in code by calling CreateDatatSet after defining its structure using FieldDefs. The first field in this ClientDataSet's structure was a Date field named StartOfWeek. Only moments later,

问题 I observed something last week that I did not expect, and will describe below. I am curious as to why this happens. Is it something internal to the TDataSet class, an artifact of the TDBGrid, or something else? The order of the fields in an open ClientDataSet changed. Specifically, I created a ClientDataSet in code by calling CreateDatatSet after defining its structure using FieldDefs. The first field in this ClientDataSet's structure was a Date field named StartOfWeek. Only moments later,

问题 I'm creating a TClientDataSet and TDataSetProvider in code in Delphi, and loading the data from a TUniQuery (Devart UniDAC). After setting the properties for the dataset provider and the clientdataset, I try to open the clientdataset and get the runtime exception: "Missing data provider or data packet". I'm not sure why its happening and would be glad if anyone could point out what exactly is wrong. This is my code: //uq is a TUniQuery correctly set to an active TUniConnection cdsFirstNames :

问题 I'm creating a TClientDataSet and TDataSetProvider in code in Delphi, and loading the data from a TUniQuery (Devart UniDAC). After setting the properties for the dataset provider and the clientdataset, I try to open the clientdataset and get the runtime exception: "Missing data provider or data packet". I'm not sure why its happening and would be glad if anyone could point out what exactly is wrong. This is my code: //uq is a TUniQuery correctly set to an active TUniConnection cdsFirstNames :

问题 With a dynamically created TFDQuery , TClientDataSet , and TDataSetProvider I bump into the "Missing data provider or data packet" with this code: procedure ResetSavedPasswords(ADataModuleDataBaseAdmin : TDataModuleDataBaseAdmin); var lQuery : TFDQuery; lCDS : TClientDataSet; lProvider : TDataSetProvider; begin lFrmBezig := TFormBezig.Create(nil); lQuery := TFDQuery.Create(nil); lProvider := TDataSetProvider.Create(Application); lCDS := TClientDataSet.Create(nil); try lQuery.Connection :=

来源： https://stackoverflow.com/questions/59926507/inserting-after-the-last-record-bottom-shown-in-dbgrid

问题 Say that I temporarily want to disable the OnCalcFields event (eg. by setting cdsCalcFields := nil ) during a time-consuming operation on a TClientDataSet. How can I tell the TClientDataSet to perform a recalculation of the calculated fields when I re-attach the OnCalcFields method? Another situation that might require a manual recalculation is the situation where some of the calculated fields are depending on other datasets (eg. a calculated field is used to temporarily hold some aggregated

问题 I need to read Files that are written with the TClientDataset class from Delphi with .NET Code. The Solution mentioned here does not work for me. 回答1: "A dotNet program that does not run on Windows platform" means to me that you're deploying a Mono application. Possibly on Linux, if that's the case try WINE and see if the Delph app suggested above works as expected. If yes, your problem of leaving the dotnet app machine is solved as both will run on the same hardware without communication

问题 I´m declaring MidasLib to avoid dll hell caused by Midas.dll in some clients. The code below runs in about 2350ms. If I remove the MidaLib declaration in uses it starts to run in just 45ms!! The data.xml file was saved with TClientDataSet.SaveToFile method, has 5000 records and its size is about 600Kb. Does anybody knows how to explain this weird behavior? I can confirm the problem in Delphi XE2 upd 3 and in Delphi XE3 upd 2. Thanks. program Loader; {$APPTYPE CONSOLE} {$R *.res} uses MidasLib

问题 I´m declaring MidasLib to avoid dll hell caused by Midas.dll in some clients. The code below runs in about 2350ms. If I remove the MidaLib declaration in uses it starts to run in just 45ms!! The data.xml file was saved with TClientDataSet.SaveToFile method, has 5000 records and its size is about 600Kb. Does anybody knows how to explain this weird behavior? I can confirm the problem in Delphi XE2 upd 3 and in Delphi XE3 upd 2. Thanks. program Loader; {$APPTYPE CONSOLE} {$R *.res} uses MidasLib