Re: How To Write And Comsume An Async Method - C# Discussion Boards

12-Jun-20 6:47

I have code in my DAL that I want to call from the UI asynchronously in my WPF app. I think I have this right, but I'd like to get your opinion.

DAL Interface

public interface IDAL
{
    Task<List<ReportData>> GetReportData(ReportArgsEntity args);
}

DAL

public class MyDAL : IDAL
{
    public Task<List<ReportData>> GetReportData(ReportArgsEntity args)
    {
        var t = Task.Factory.StartNew(() => 
        {
            List<ReportData> results = new List<ReportData>();

            // Get report data here

            return results;
        });

        return t;
    }
}

BL Interface

public interface IBL
{
    Task<List<ReportData>> GetReportData(ReportArgsEntity args);
}

public class MyBL : IBL
{
    IDAL _dal;
    public MyBL()
    {
        _dal = new MyDAL();
    }
    public Task<List<ReportData>> GetReportData(ReportArgsEntity args)
    {
        return _dal.GetReportData(args);
    }
}

View Model

public class MyViewModel
{
    IBL _bizLayer;

    public MyViewModel()
    {
        _bizLayer = new MyBL();
    }

    private async void RunReport()
    {
        var args = new ReportArgsEntity()
        {
            // Set properties here
        };

        var reportData = await _bizLayer.GetReportData(args);

        // When the data comes back, show he report
    }
}

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming12-Jun-20 8:09

12-Jun-20 8:09

I'm not convinced by that Task.Factory.StartNew call.

First of all, you should really be using Task.Run instead:
Task.Run vs Task.Factory.StartNew | .NET Parallel Programming[^]

But unless that code is CPU-bound, you've not really gained much. Most data access code is going to be IO-bound, so it should be using the async version of whatever methods you're using to load the data.

For example, if you're using a SqlCommand to load the data:
SqlConnection.OpenAsync(CancellationToken) Method (System.Data.SqlClient) | Microsoft Docs[^]
SqlCommand.ExecuteReaderAsync Method (System.Data.SqlClient) | Microsoft Docs[^]
SqlDataReader.ReadAsync(CancellationToken) Method (System.Data.SqlClient) | Microsoft Docs[^]

public async Task<List<ReportData>> GetReportData(ReportArgsEntity args)
{
    // Make sure we're not blocking the UI thread:
    await Task.Yield().ConfigureAwait(false);
    
    using (var connection = new SqlConnection("..."))
    using (var command = new SqlCommand("...", connection))
    {
       await connection.OpenAsync();
       
       using (var reader = await command.ExecuteReaderAsync(CommandBehavior.CloseConnection))
       {
           var results = new List<ReportData>();
           
           while (await reader.ReadAsync())
           {
               ...
           }
           
           return results;
       }
    }
}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois12-Jun-20 9:54

12-Jun-20 9:54

Richard Deeming wrote:
First of all, you should really be using Task.Run instead:

I thought Task.Run and Task.Factory.StartNew do basically the same thing?

I'm using Linq To SQL

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming14-Jun-20 23:44

DataContext.GetCommand(IQueryable) Method (System.Data.Linq) | Microsoft Docs[^]
DataContext.Translate Method (System.Data.Linq) | Microsoft Docs[^]

14-Jun-20 23:44

As Stephen said in the blog post, Task.Run is equivalent to:

Task.Factory.StartNew(someAction, CancellationToken.None, TaskCreationOptions.DenyChildAttach, TaskScheduler.Default);

It is possible to get proper async support in LINQ to SQL, although it's not perfect. For example:

public static async Task<List<T>> ToListAsync(this IQueryable<T> query, DbContext context, CancellationToken cancellationToken = default)
{
    if (query is null) throw new ArgumentNullException(nameof(query));
    if (context is null) throw new ArgumentNullException(nameof(context));
    
    using (var command = (SqlCommand)context.GetCommand(query))
    {
        await command.Connection.OpenAsync(cancellationToken);
        
        using (var reader = await command.ExecuteReaderAsync(CommandBehavior.CloseConnection, cancellationToken))
        {
            return _context.Translate<T>(reader).ToList();
        }
    }
}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois15-Jun-20 7:31

15-Jun-20 7:31

Richard Deeming wrote:
using (var reader = await command.ExecuteReaderAsync(CommandBehavior.CloseConnection, cancellationToken))
{
return _context.Translate<T>(reader).ToList();
}

OK, so I'm using Linq to SQL. What more can I do to make the method async? The Command has the ExecuteReaderAsync method, but my Linq to SQL code won't have any of that. For example:

public Task<List<ReportData>> GetReportData(ReportArgsEntity args)
{
    var t = Task.Run(() => 
    {
        var results = new List<ReportData>();

        using (var dc = GetDataContecxt())
        {
            results = (from c in dc.Companies
                        join ih in dc.InvoiceHeaders on c.Id equals ih.CustomerId
                        join id in dc.InvoiceDetails on ih.Id equals id.HeaderId
                        where c.Completed
                        select new ReportData
                        {
                            // Add data to properties here
                        }).ToList();
        }

        return results;
    });

    return t;
}

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming15-Jun-20 7:38

15-Jun-20 7:38

Use the extension method from my previous post. For example:

public async Task<List<ReportData>> GetReportData(ReportArgsEntity args)
{
    // Move the execution off the UI thread:
    await Task.Yield().ConfigureAwait(false);
    
    var query = from c in dc.Companies
                join ih in dc.InvoiceHeaders on c.Id equals ih.CustomerId
                join id in dc.InvoiceDetails on ih.Id equals id.HeaderId
                where c.Completed
                select new ReportData
                {
                    // Add data to properties here
                };
    
    return await query.ToListAsync(dc);
}

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois15-Jun-20 7:41

15-Jun-20 7:41

I see.

The whole reason I'm asking is that right now all of the code is on the UI thread. But we're going to be moving the BL & DAL to Controllers in an ASP.Net Web API. So the UI will need to fire & forget each call and await the results.

Given that, and other that what we've already discussed, any reason this wouldn't work?

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

Richard Deeming15-Jun-20 7:50

15-Jun-20 7:50

The Web API action can be async, so this code will just work as-is. You might want to drop the Task.Yield line though, since you're not worried about blocking the UI thread.

The client code can make async requests to the web API - how easy that is will depend on which library you're using to call it. Using async and await will ensure that the UI thread isn't blocked whilst you're waiting for a response from the network.

"These people looked deep within my soul and assigned me a number based on the order in which I joined."
- Homer

Kevin Marois15-Jun-20 9:01

Removing a field from jSon String

15-Jun-20 9:01

Thanks Richard

If it's not broken, fix it until it is.
Everything makes sense in someone's mind.
Ya can't fix stupid.

simpledeveloper11-Jun-20 8:00

simpledeveloper

11-Jun-20 8:00

I am storing jSon string as hexa-decimal or some characters string, its all working fine whan I retrieving as json string in my code, but there is one field I want to remove from the jSob object after I retrieved.

var t = StoredProcedures.SP_GlobalSearch.Execute(new SP_GlobalSearch_Params
                        {
                            Search = request.search,
                            SourceKey = "",
                            Skip = start,
                            Take = length,
                            ShowDeleted = false
                        }).Select(x => new SP_GlobalSearch
                        {
                            JsonObject = x.Data != null ? new JavaScriptSerializer().DeserializeObject(x.Data.Replace("ï»¿", "")) : null,
                            Date = x.Date,
                            JsonObjectId = x.JsonObjectId,
                            SourceKey = x.SourceKey,
                            SourceId = x.SourceId,
                            TotalCount = x.TotalCount
                        });
                                           
                        var response = t?.ToList();
    
                        var jsondata = new DataTableResponse<SP_GlobalSearch>
                        {
                            totalCount = (int)response.Where(x => x.TotalCount != null).FirstOrDefault().TotalCount,
                            data = response.Where(x => x.TotalCount == null)
                        };
                       
                        var jsonResult = Json(jsondata);
                        jsonResult.MaxJsonLength = Int32.MaxValue;
                        return jsonResult;

I am reading the text as jSon with the below statement,

JavaScriptSerializer().DeserializeObject(x.Data.Replace("ï»¿", ""))

I want to remove the violations field from it, any help please. Thanks in advance

Here is my json:

{
   "InspectionResultId":846,
   "InspectionResultNumber":"T00846",
   "InspectionRequestId":507,
   "InspectionRequestNumber":"R00507",
   "CaseId":689,
   "InspectionResultStatusId":605,
   "EnforcementSectionId":104,
   "ViolationTypeId":603,
   "DateOfInspection":"\/Date(1589439600000)\/",
   "InspectionComment":"send to office staff, open investigation",
   "InspectedCompanyDataId":964,
   "ContactTypeId":701,
   "EnteredById":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
   "InspectionResultTimestamp":"\/Date(1588280817470)\/",
   "DateCreated":"\/Date(1588280817487)\/",
   "DateUpdated":"\/Date(1588281867967)\/",
   "CreatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
   "UpdatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
   "Case":{
      "RelatedContactId":0,
      "CaseId":689,
      "CaseNumber":"I00689",
      "IsInvestigation":true,
      "CaseStatusId":801,
      "InspectionItemSourceId":211,
      "EnforcementSectionId":104,
      "ReminderDate":"\/Date(1590044400000)\/",
      "PreCaseSummary":"send to office staff, open investigation",
      "AssignedToInspectorId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "CaseTimestamp":"\/Date(1588281867403)\/",
      "CaseCompanyId":964,
      "DateCreated":"\/Date(1588281867437)\/",
      "DateUpdated":"\/Date(1588281867840)\/",
      "CreatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "UpdatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "IsDeleted":false,
      "InterpreterNeeded":false,
      "VoluntaryDisclosure":false,
      "PenaltyAdjustment":0,
      "Company":{
         "ContactId":964,
         "ContactTypeId":1000,
         "FirstName":"04.30.2020 new co",
         "Notes":"new request",
         "Active":true,
         "Created":"\/Date(1588279909680)\/",
         "Updated":"\/Date(1588279909680)\/",
         "DateCreated":"\/Date(1588279909680)\/",
         "DateUpdated":"\/Date(1588279909680)\/",
         "IsEJArea":false,
         "CreatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
         "UpdatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
         "Classification":{

         },
         "Class":"Company",
         "IsSpecial":false,
         "Address":{
            "Street1":"5678 Street",
            "City":"Sacramento",
            "StateCode":"CA",
            "Zip":"95812",
            "Country":"0"
         }
      }
   },
   "InspectionResultStatus":{
      "InspectionResultStatusId":605,
      "InspectionResultStatusName":"Clean",
      "InspectionResultStatusSortOrder":5
   },
   "EnforcementSection":{
      "EnforcementSectionId":104,
      "EnforcementSectionName":"STBES",
      "EnforcementSectionSortOrder":0,
      "BranchId":2
   },
   "InspectedCompanyData":{
      "ContactId":964,
      "ContactTypeId":1000,
      "FirstName":"04.30.2020 new co",
      "Notes":"new request",
      "Active":true,
      "Created":"\/Date(1588279909680)\/",
      "Updated":"\/Date(1588279909680)\/",
      "DateCreated":"\/Date(1588279909680)\/",
      "DateUpdated":"\/Date(1588279909680)\/",
      "IsEJArea":false,
      "CreatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "UpdatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "Classification":{

      },
      "Class":"Company",
      "IsSpecial":false
   },
   "InspectionItems":[
      {
         "InspectionItemId":1054,
         "InspectionItemNumber":"T00000",
         "InspectionRequestId":507,
         "InspectionResultId":846,
         "CaseId":689,
         "InspectionItemSourceId":229,
         "IsCreatedInCase":false,
         "ShowYearMakeModel":"",
         "ShowYearMakeModelVIN":"",
         "GrossWeight":0.00,
         "RegHoldSet":false,
         "InspectionItemTimestamp":"\/Date(1588280802553)\/",
         "DateCreated":"\/Date(1588280802567)\/",
         "DateUpdated":"\/Date(1588281868153)\/",
         "CreatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
         "UpdatedByUserId":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
         "Violations":[

         ]
      }
   ],
   "CompletedBy":[
      {
         "IsActive":true,
         "FirstName":"Daphne",
         "LastName":"Greene",
         "ObjectGUID":"S-1-5-21-1538631513-416410304-3002070310-33442",
         "NameLoginFormat":"dgreene",
         "NameFirstLast":"Daphne Greene",
         "NameLastFirst":"Greene Daphne",
         "Email":"daphne.greene@arb.ca.gov",
         "EmailConfirmed":false,
         "SecurityStamp":"e061e77e-c93e-4b9e-8497-4852b5cb4ca2",
         "PhoneNumberConfirmed":false,
         "TwoFactorEnabled":false,
         "LockoutEnabled":false,
         "AccessFailedCount":0,
         "Id":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
         "UserName":"dgreene"
      }
   ],
   "EnteredBy":{
      "IsActive":true,
      "FirstName":"Daphne",
      "LastName":"Greene",
      "ObjectGUID":"S-1-5-21-1538631513-416410304-3002070310-33442",
      "NameLoginFormat":"dgreene",
      "NameFirstLast":"Daphne Greene",
      "NameLastFirst":"Greene Daphne",
      "Email":"daphne.greene@arb.ca.gov",
      "EmailConfirmed":false,
      "SecurityStamp":"e061e77e-c93e-4b9e-8497-4852b5cb4ca2",
      "PhoneNumberConfirmed":false,
      "TwoFactorEnabled":false,
      "LockoutEnabled":false,
      "AccessFailedCount":0,
      "Id":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "UserName":"dgreene"
   },
   "MyGridContacts":[

   ],
   "CreatedByUser":{
      "IsActive":true,
      "FirstName":"Daphne",
      "LastName":"Greene",
      "ObjectGUID":"S-1-5-21-1538631513-416410304-3002070310-33442",
      "NameLoginFormat":"dgreene",
      "NameFirstLast":"Daphne Greene",
      "NameLastFirst":"Greene Daphne",
      "Email":"daphne.greene@arb.ca.gov",
      "EmailConfirmed":false,
      "SecurityStamp":"e061e77e-c93e-4b9e-8497-4852b5cb4ca2",
      "PhoneNumberConfirmed":false,
      "TwoFactorEnabled":false,
      "LockoutEnabled":false,
      "AccessFailedCount":0,
      "Id":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "UserName":"dgreene"
   },
   "UpdatedByUser":{
      "IsActive":true,
      "FirstName":"Daphne",
      "LastName":"Greene",
      "ObjectGUID":"S-1-5-21-1538631513-416410304-3002070310-33442",
      "NameLoginFormat":"dgreene",
      "NameFirstLast":"Daphne Greene",
      "NameLastFirst":"Greene Daphne",
      "Email":"daphne.greene@arb.ca.gov",
      "EmailConfirmed":false,
      "SecurityStamp":"e061e77e-c93e-4b9e-8497-4852b5cb4ca2",
      "PhoneNumberConfirmed":false,
      "TwoFactorEnabled":false,
      "LockoutEnabled":false,
      "AccessFailedCount":0,
      "Id":"7f54fa3e-b5cd-4b2e-9490-92f64c022246",
      "UserName":"dgreene"
   }
}

I want to remove the Violations part from the jSon object, can you please help me in this regards thank you.

modified 11-Jun-20 18:08pm.

OriginalGriff11-Jun-20 22:44

OriginalGriff

11-Jun-20 22:44

You can't "remove" the violations from the JSON once you have read it: either it's still in the JSON string (in which case you probably want to look at a Regex or similar to remove fit from that) or it's a part of the InspectionItem class and the best you can do is set the InspectionItem.Violations property to null for each instance in your data.
You can't "delete" a property from a class after compilation!

Probably the best way would be to use a Regex to remove the Violations section from the JSON source before you deserialize it - but there could be some significant work involved in writing that, given that the sample you show does not contain any data in the Violations section, so we have no idea how complicated that JSON clause might be when filled in. Complicated clause == complicated Regex! Laugh | :laugh:

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
AntiTwitter: @DalekDave is now a follower!

simpledeveloper12-Jun-20 9:05

simpledeveloper

12-Jun-20 9:05

Yeah making that property value null is fine - can you please help me in this regards please? Or can you please help me with the Regex please? Thank you.

OriginalGriff12-Jun-20 9:06

OriginalGriff

12-Jun-20 9:06

You don't know how to set a property?

Why are you playing with JSON if you don't know the (very, very) basics?

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
AntiTwitter: @DalekDave is now a follower!

Is there any good C# desktop library to implement Card liked UI dashboard?

James Curran17-Jun-20 20:23

James Curran

17-Jun-20 20:23

To answer this we need to know the type of SP_GlobalSearch.JsonObject. If it's something like a InspectionResult class or even a dynamic, then it's simple:

var response = t==null? null : t.Select(r=>{r.InspectionItems.Violations = null; return r;}).ToList();
 //                   purists will hate this ^^^^

If JsonObject is a System.Object, then things get messy. Best to change than to one of the options given above.

Truth,

James

yccheok11-Jun-20 6:31

yccheok

11-Jun-20 6:31

I have been away from Windows desktop development environment (Using C++ MFC) for many years.

Recently, I plan to port an Android app to Windows desktop environment.

I plan to use C# as my tech stack.

However, I have 0 clue on how to develop a

- Card liked UI dashboard
- Achieve drag-n-move animation

Our Android app looks like - Drag and move animation - YouTube[^]

Do you have any suggestion library, which can help me to implement so?

Thank you.

Re: Is there any good C# desktop library to implement Card liked UI dashboard?

Richard MacCutchan11-Jun-20 21:36

Richard MacCutchan

11-Jun-20 21:36

I am not sure what you mean by "Card liked UI dashboard", but drag and drop is fully supported in .NET: Walkthrough: Perform a drag-and-drop operation - Windows Forms | Microsoft Docs[^].

Re: Is there any good C# desktop library to implement Card liked UI dashboard?

yccheok12-Jun-20 6:13

yccheok

12-Jun-20 6:13

In the video, it shows how "Card liked UI dashboard" look like.

Also, this is a JavaScript implementation of "Card liked UI dashboard" - Column grid demo[^]

As you can see, the JavaScript example supports drag-n-move, and resizing.

Any idea on where I can get an equivalent C# desktop library to implement such?

Thanks.

Re: Is there any good C# desktop library to implement Card liked UI dashboard?

Richard MacCutchan12-Jun-20 6:43

Richard MacCutchan

12-Jun-20 6:43

yccheok wrote:
where I can get an equivalent C# desktop library to implement such?

If you want a ready made lbrary then Google is the place to search. Or you could just write your own code to move things around on a form.

How to handle excel - multiple sheets integration with ODBC Driver connection in C#

Member 1485915110-Jun-20 3:10

Member 14859151

10-Jun-20 3:10

Hello Everyone,

I'm currently trying to fetch data from 1 excel workbook, which is having multiple sheets

Please find my excel sheet: here

Please find my code to get the excel data

<pre>public static T GetAllTestData<T>(string keyName)
        {
            using (var connection = new
                          OdbcConnection(TestDataFileConnection()))
            {
                connection.Open();
                System.Data.DataTable dt = null;
                dt = connection.GetSchema(OdbcMetaDataCollectionNames.Tables, null);
                String[] excelSheets = new String[dt.Rows.Count];
                var i = 0;
                // Add the sheet name to the string array.
                foreach (DataRow row in dt.Rows)
                {
                    excelSheets[i] = row["TABLE_NAME"].ToString();
                    i++;
                }
                T value = default(T);
                // Loop through all of the sheets if you want to...
                for (int j = 0; j < excelSheets.Length; j++)
                {
                    // Query each excel sheet.
                    var query = string.Format("select * from [{0}] where TestName = '{1}'", excelSheets[j], keyName);
                    value = connection.Query<T>(query).FirstOrDefault();
                }
                //Console.Write(list1);
                connection.Close();
                return value;
            }
        }

Call to the function:

var param1 = AccessExcelData.GetAllTestData<TestDataModel>("Test1");

Issue:

I want to get all the values from all the sheets in excel which has TestName as "Test1" but in my method, variable value keep getting override which makes it tough for me to get all the values

Can someone look into this, or If I can have another approach for handling excel data test in c#

Re: How to handle excel - multiple sheets integration with ODBC Driver connection in C#

jsc423-Jul-20 6:43

jsc42

3-Jul-20 6:43

Your problem is in the following loop ...

for (int j = 0; j < excelSheets.Length; j++)
{
    // Query each excel sheet.
    var query = string.Format("select * from [{0}] where TestName = '{1}'", excelSheets[j], keyName);
    value = connection.Query<T>(query).FirstOrDefault();
}

As soon as you have got a value in the value field, you move on to the next sheet. You need to either do something with the value before going round the next iteration of the loop or store the values (one per sheet) e.g. in an array, and then process them all together after completing the loop.

System.Timers.Timer() called method doesn't run all code

jsmjsm10-Jun-20 1:09

jsmjsm

10-Jun-20 1:09

Not all code within the called method "displayTimeEvent" runs every 2 seconds.

var awaitExit = new System.Timers.Timer();
    awaitExit.Interval = 2000;
    awaitExit.Elapsed += displayTimeEvent;
    awaitExit.Start();


void displayTimeEvent(object source, ElapsedEventArgs e)
{	

// This code runs	
int s = DateTime.Now.Second;
displayMessage("Second: " + s.ToString());

// This code doesn't	
label1.Text += ".";				
progressBar1.Increment(20);		
}

Re: System.Timers.Timer() called method doesn't run all code

Richard Deeming10-Jun-20 1:30