Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language) - C# Discussion Boards

Re: Writing ActiveX for MS Access (VS 2019)

21-Jan-21 3:36

There is no clear reason why you think you need "ActiveX" in this scenario.

C# can read MS Access; create the QR image; and store / print "it".

The "Access report with the QR (string)" is some byproduct of Access.

Connect to data in an Access database - Visual Studio | Microsoft Docs

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

mac2782821-Jan-21 4:02

mac27828

21-Jan-21 4:02

Yes. I found an example of what your talking about here. Good suggestion. Thanks.

C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

Upin L18-Jan-21 19:02

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

18-Jan-21 19:02

Hello Everyone!
I am C#/ASP.NET new learning
And my english is very bad (I am Taiwanese)

My Boss give me a .NET test
the problem is like say : Use swtich(expr) expression can action on byte?, long?, String?
My answer is
byte => OK, long => unknow, String => OK

But my boss give me answer is
switch(expr) expression need is integer type / integer expression
Os long and string is not use on switch

After I fund answer in internet like
Switch Statement in C# - GeeksforGeeks

The first paragraph: The switch expression is of integer type such as int, char, byte, or short, or of an enumeration type, or of string type

Can someone talk me true answer?!
I vary appreciate, thank your

*I can not ask on Chinese Webpage beacuse i afraid my boss see this

OriginalGriff18-Jan-21 20:09

OriginalGriff

18-Jan-21 20:09

it's possible your boss is using the wrong words: there are two types of switch in c# And he may be getting confused.

Strings, integers of all forms (including long), chars, enums are all legal in C# switch statements: C# switch statement | Microsoft Docs[^]

With switch expressions, the range is even bigger: switch expression - C# reference | Microsoft Docs[^]

"I have no idea what I did, but I'm taking full credit for it." - ThisOldTony
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Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

Upin L24-Jan-21 14:27

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

24-Jan-21 14:27

thank your reply
I guess boss get c/c++ test not .NET/C# test
Unfortunately my test is failed

Christian Graus19-Jan-21 9:54

Christian Graus

19-Jan-21 9:54

I guess if he's saying something that is untrue, create a project and show him you can switch on almost anything? That was a major step forward, he's thinking of C++ I reckon

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

Upin L24-Jan-21 14:40

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

24-Jan-21 14:40

thank your reply

Unfortunately i can not do this
(i mean => create a project and show him you can switch on almost anything...)
I am new for C#/.Net so i can not refute my boss

Right concept is very important for learning
And thanks you talk me the right answer

Christian Graus24-Jan-21 14:50

Christian Graus

24-Jan-21 14:50

That's just not how sh*t works. If you don't know C# well enough to show your boss he is wrong, you are in a world of trouble. You clearly should not have a boss who pays you to write code right now. You should leave this awful job, enrol in a course, and learn C#.

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

Upin L25-Jan-21 19:30

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

25-Jan-21 19:30

I know your meaning, and thanks your recommend

originally I am PHP engineer(almost 1 year), not C#/.Net engineer
But my boss want to use C# development
Os now I need use PHP and C# at same time/job

don't worry about trouble(

you are in a world of trouble

)
My boss is not first time do this(give me inappropriate information)
And thank you

20212a19-Jan-21 10:40

20212a

19-Jan-21 10:40

I cannot remember but it seems like a language I used in the past only allowed switches on integers. Christian implies that C++ is that way so my guess is your boss is not aware that most languages do allow switch on other types.

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

Upin L24-Jan-21 14:51

Re: C# or ASP.NET swtich(expr) expression can action on byte, long, String?(Engilsh is not my native language)

24-Jan-21 14:51

thank your reply

I just found c/c++/java on network for this problem
I not found any answer for c#/.Net

Now I feel confused about this test

20212a25-Jan-21 1:13

20212a

25-Jan-21 1:13

Upin L wrote:
confused

Why? Most all programming languages allow switching on various data types.

System.Windows.Forms.DataVisualization.Charting

Member 1483694318-Jan-21 1:40

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 1:40

Hi,

I am developing a Work Load Analysis platform and there I use System.Windows.Forms.DataVisualization.Charting. The problem i have is, Xaxis is not updated when switching between different value types in runtime.
Here is the code, which i use to update chart from DateTime valuetype to int.

Here _EndWeek and _StartWeek are integer parameters pass to this method.

List<int> _Weeks = new List<int>();
int _Week_Difference = _EndWeek - _StartWeek;

for (int i = 0; i <= _Week_Difference; i++)
{
    _Weeks.Add(_StartWeek+ i);
}

chart_Utilization.Series[0].Points.Clear();
chart_Utilization.Series[1].Points.Clear();
chart_Utilization.Series[2].Points.Clear();

chart_Utilization.Series[0].XValueType = ChartValueType.Int32;
chart_Utilization.Series[1].XValueType = ChartValueType.Int32;
chart_Utilization.Series[2].XValueType = ChartValueType.Int32;

chart_Utilization.ChartAreas[0].AxisX.Interval = 1;
chart_Utilization.ChartAreas[0].AxisX.IntervalType = DateTimeIntervalType.Number;
chart_Utilization.ChartAreas[0].AxisX.IntervalOffsetType = DateTimeIntervalType.Number;

chart_Utilization.ChartAreas[0].AxisX.LabelStyle.Format = "{0:0}";
chart_Utilization.ChartAreas[0].AxisX.Minimum = 1;
chart_Utilization.ChartAreas[0].AxisX.Maximum = 53;

chart_Utilization.Update();

I would be glad, if some could help me in this case.

Gerry Schmitz18-Jan-21 2:35

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 2:35

You cleared all your points; I don't see you adding any back in.

chart_Utilization.Series[0].Points.Clear();
chart_Utilization.Series[1].Points.Clear();
chart_Utilization.Series[2].Points.Clear();

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Member 1483694318-Jan-21 5:09

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 5:09

The data is added in a loop after this piece of code. Data is added, but the X-Axis labelling is wrong. They are still in Datetime format.

Gerry Schmitz18-Jan-21 5:33

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 5:33

The x-axis usually is "time" in a time-series. You've provided no new information.

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Member 1483694318-Jan-21 6:27

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 6:27

I want to change the XAxis Value type to Int. How can i change it in runtime?
Because, the XAxis value type is dynamically changed according to the filter inputs from the user.

Gerry Schmitz18-Jan-21 15:57

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 15:57

Then add "int" (object) points after your delete the previous points.

DataPointCollection.AddXY Method (System.Web.UI.DataVisualization.Charting) | Microsoft Docs

It was only in wine that he laid down no limit for himself, but he did not allow himself to be confused by it.
― Confucian Analects: Rules of Confucius about his food

Member 1483694318-Jan-21 18:15

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 18:15

Thanks a lot for your reply. I created sample application with same code here for your reference.
This method is called when form is loaded.

private void Format_Chart()
{

    ChartArea _Area = new ChartArea("Utilization");
    _Area.AlignmentOrientation = AreaAlignmentOrientations.Vertical;
    _Area.AlignmentStyle = AreaAlignmentStyles.All;
    chart_Utilization.ChartAreas.Add(_Area);
    chart_Utilization.ChartAreas["Utilization"].Position = new ElementPosition(0, 10, 100, 90);

    chart_Utilization.Series.Clear();

    Series _Series_Current_Utilization = new Series("Current Utilization");
    _Series_Current_Utilization.ChartArea = _Area.Name;
    _Series_Current_Utilization.XValueType = ChartValueType.Date;
    _Series_Current_Utilization.YValueType = ChartValueType.Double;
    _Series_Current_Utilization.YValuesPerPoint = 1;
    _Series_Current_Utilization.ChartType = SeriesChartType.StackedColumn;
    _Series_Current_Utilization.Color = Color.FromArgb(200, 20, 191, 154);

    Series _Series_Over_Utilization = new Series("Over Utilization");
    _Series_Over_Utilization.ChartArea = _Area.Name;
    _Series_Over_Utilization.XValueType = ChartValueType.Date;
    _Series_Over_Utilization.YValueType = ChartValueType.Double;
    _Series_Over_Utilization.YValuesPerPoint = 1;
    _Series_Over_Utilization.ChartType = SeriesChartType.StackedColumn;
    _Series_Over_Utilization.Color = Color.Red;//Color.FromArgb(80, 255, 0, 0);

    Series _Series_Target_Utilization = new Series("Target Utilization");
    _Series_Target_Utilization.ChartArea = _Area.Name;
    _Series_Target_Utilization.XValueType = ChartValueType.Date;
    _Series_Target_Utilization.YValueType = ChartValueType.Double;
    _Series_Target_Utilization.YValuesPerPoint = 1;
    _Series_Target_Utilization.ChartType = SeriesChartType.Line;
    _Series_Target_Utilization.Color = Color.FromArgb(200, 20, 191, 154);

    chart_Utilization.Series.Add(_Series_Current_Utilization);
    chart_Utilization.Series.Add(_Series_Over_Utilization);
    chart_Utilization.Series.Add(_Series_Target_Utilization);

    chart_Utilization.Legends[_Series_Current_Utilization.Legend].Docking = Docking.Top;
    chart_Utilization.Legends[_Series_Current_Utilization.Legend].Alignment = StringAlignment.Center;

    chart_Utilization.Legends[_Series_Target_Utilization.Legend].Docking = Docking.Top;
    chart_Utilization.Legends[_Series_Target_Utilization.Legend].Alignment = StringAlignment.Center;

    chart_Utilization.Legends[_Series_Over_Utilization.Legend].Docking = Docking.Top;
    chart_Utilization.Legends[_Series_Over_Utilization.Legend].Alignment = StringAlignment.Center;

    chart_Utilization.ChartAreas[0].AxisX.LabelStyle.Format = "yyyy-MM-dd";
    chart_Utilization.ChartAreas[0].AxisX.Interval = 1;
    chart_Utilization.ChartAreas[0].AxisX.IntervalType = DateTimeIntervalType.Days;
    chart_Utilization.ChartAreas[0].AxisX.IntervalOffset = 1;

    chart_Utilization.ChartAreas[0].AxisY.Maximum = (double)(120);
    chart_Utilization.ChartAreas[0].AxisY.Minimum = (double)(0);
}

There are two button click events to change the value type of XAxis.

1. To change to ChartValueType.Date

private void btnDates_Click(object sender, EventArgs e)
        {
            List<double> _Values = new List<double>();
            int _Count = 1;

            for(int i = 0; i < 10; i++)
            {
                _Values.Add(i * 2.5d);
            }
            chart_Utilization.Series["Current Utilization"].Points.Clear();
            chart_Utilization.Series["Over Utilization"].Points.Clear();
            chart_Utilization.Series["Target Utilization"].Points.Clear();

            chart_Utilization.Series["Current Utilization"].XValueType = ChartValueType.Date;
            chart_Utilization.Series["Over Utilization"].XValueType = ChartValueType.Date;
            chart_Utilization.Series["Target Utilization"].XValueType = ChartValueType.Date;

            chart_Utilization.ChartAreas[0].AxisX.Interval = 1;
            chart_Utilization.ChartAreas[0].AxisX.IntervalType = DateTimeIntervalType.Days;
            chart_Utilization.ChartAreas[0].AxisX.IntervalOffset = 1;

            foreach(double _dval in _Values)
            {
                var _point_current = new DataPoint(chart_Utilization.Series["Current Utilization"]);
                var _point_target = new DataPoint(chart_Utilization.Series["Target Utilization"]);
                var _point_over = new DataPoint(chart_Utilization.Series["Over Utilization"]);

                _point_current.SetValueXY(new DateTime(DateTime.Now.Year, DateTime.Now.Month, _Count), _dval);
                _point_target.SetValueXY(new DateTime(DateTime.Now.Year, DateTime.Now.Month, _Count), _dval);
                _point_over.SetValueXY(new DateTime(DateTime.Now.Year, DateTime.Now.Month, _Count), _dval);

                chart_Utilization.Series["Current Utilization"].Points.Add(_point_current);
                chart_Utilization.Series["Target Utilization"].Points.Add(_point_target);
                chart_Utilization.Series["Over Utilization"].Points.Add(_point_over);

                _Count++;
            }
        }

2. To change to ChartValue type to Int

private void btnInt_Click(object sender, EventArgs e)
        {
            List<double> _Values = new List<double>();
            int _Count = 1;

            for (int i = 0; i < 10; i++)
            {
                _Values.Add(i * 5d);
            }

            chart_Utilization.Series[0].Points.Clear();
            chart_Utilization.Series[1].Points.Clear();
            chart_Utilization.Series[2].Points.Clear();

            chart_Utilization.Series[0].XValueType = ChartValueType.Int32;
            chart_Utilization.Series[1].XValueType = ChartValueType.Int32;
            chart_Utilization.Series[2].XValueType = ChartValueType.Int32;

            chart_Utilization.ChartAreas[0].AxisX.Interval = 1;
            chart_Utilization.ChartAreas[0].AxisX.IntervalType = DateTimeIntervalType.NotSet;
            chart_Utilization.ChartAreas[0].AxisX.IntervalOffsetType = DateTimeIntervalType.NotSet;

            chart_Utilization.ChartAreas[0].AxisX.LabelStyle.Format = "{0:0}";
            chart_Utilization.ChartAreas[0].AxisX.Minimum = 1;
            chart_Utilization.ChartAreas[0].AxisX.Maximum = 53;

            chart_Utilization.Update();

            foreach (double _dval in _Values)
            {
                var _point_current = new DataPoint(chart_Utilization.Series["Current Utilization"]);
                var _point_target = new DataPoint(chart_Utilization.Series["Target Utilization"]);
                var _point_over = new DataPoint(chart_Utilization.Series["Over Utilization"]);

                _point_current.SetValueXY(_Count, _dval);
                _point_target.SetValueXY(_Count, _dval);
                _point_over.SetValueXY(_Count, _dval);

                chart_Utilization.Series["Current Utilization"].Points.AddXY(_Count, _dval);
                chart_Utilization.Series["Target Utilization"].Points.AddXY(_Count, _dval);
                chart_Utilization.Series["Over Utilization"].Points.AddXY(_Count, _dval);

                _Count++;
            }
        }

When i switch from Date to Int, the XAxis labelling still apears as DateTime value type. This is my issue.
Please let me know in which way i can solve this issue.

Member 1483694318-Jan-21 19:32

Re: System.Windows.Forms.DataVisualization.Charting

18-Jan-21 19:32

I solved the problem by myself.

It is by setting IsXValueIndexed = true for each series allocated for the chart area.

Gerry Schmitz19-Jan-21 4:31