Develop Reference

assigning the model list property value to the variable in MVC view

I am using a model named as Mdl_home_page the model consist of bunch of properties like :
public class Mdl_home_page
{
public SelectList LocationSelectList { get; set; }
public List<tbl_devices> lstOfDevices { get; set; }
}
The tbl_devices is my another model which contains information about devices.
The tbl_device model is :
public partial class tbl_devices
{
public int device_id { get; set; }
public string device_name { get; set; }
public string device_ip { get; set; }
public string device_type { get; set; }
public string device_placement_coordinates_x { get; set; }
public string device_placement_coordinates_y { get; set; }
}
I passed the model to the view like this:
#model SymphonyWebServer.Models.Mdl_Home_page
Now I have a HTML canvas on which I have an image of map where I want to display the rectangles to depict placement of a device. to do this I want to use device_placement_coordinates_x and device_placement_coordinates_y properties of tbl_device model.
So, I made a code like :
var xvalue = 100, yvalue = 100;
for (var i = 0; i < #Model.lstOfDevices.Count; i++) {
xvalue = #Model.lstOfDevices[i].device_placement_coordinates_x;
yvalue = #Model.lstOfDevices[i].device_placement_coordinates_y;
ctx.fillRect(xvalue, yvalue,50,50);
}
ctx is my context object of the canvas.
But It is giving me error: the name 'i' does not exist in the current context.
Please help to resolve the problem !

The variable i is an JavaScript variable. You can't use it as the index in the C# listOfDevices array.
Why not just loop through the array using foreach, and run JavaScript code inside? You can use #: or <text /> to switch between C# Razor mode and JavaScript mode.
var xValue = 100, yValue = 100;
#foreach (var device in Model.lstOfDevices)
{
<text>
xValue = #device.device_placement_coordinates_x;
yValue = #device.device_placement_coordinates_y;
ctx.fillRect(xValue, yValue, 50, 50);
</text>
}

How can I convert javascript var obj = {}; to C#?

I have the following javascript code:
var key = "Mykey" + NextNumber.toString();
var value = {"Name":"Tony","Width":"150","Height":"320"};
var valuejson = JSON.stringify(value);
var obj = {};
obj[key] = valuejson
I know how to create valuejson in C#, but I don't know how to create something similar like var obj = {}; in C#. How can I do that in C#?
key and valuejson in C#:
public class MyValue
{
public string Name { get; set; }
public string Width { get; set; }
public string Height { get; set; }
}
MyValue value = new MyValue();
value.Name = "Tony";
value.Width = "150";
value.Height = "320";
string jsonValue = JsonConvert.SerializeObject(value);
string key = "Mykey" + NextNumber.toString();

You could try to use a dynamic object which works similar to {} in javascript... But... You have to be CAREFUL, example:
public class test
{
public class MyValue
{
public string Name { get; set; }
public string Width { get; set; }
public string Height { get; set; }
}
public void testing()
{
MyValue value = new MyValue();
value.Name = "Tony";
value.Width = "150";
value.Height = "320";
dynamic jsonValue = new { keyA = value };
string height = jsonValue.keyA.Height;
}
}
EDI:
Actually, I read a bit more carefully your need, and a dictionary can also suit your needs:
public class test
{
public class MyValue
{
public string Name { get; set; }
public string Width { get; set; }
public string Height { get; set; }
}
Dictionary<string, MyValue> dic = new Dictionary<string, MyValue>();
public void testing()
{
string key = "Mykey" + NextNumber.toString();
MyValue value = new MyValue();
value.Name = "Tony";
value.Width = "150";
value.Height = "320";
dic.Add(key, value);
}
}
Since you where asking for the equivalent of a var x = {} I suggested the dynamic but I see you want to create a key and associate that value to that key.

If you're looking for an object whose members can be dynamically added and removed at run time (like in Javascript) then the ExpandoObject class should fit your needs.
dynamic employee = new ExpandoObject();
employee.Name = "John Smith";
employee.Age = 33;
foreach (var property in (IDictionary<String, Object>)employee)
{
Console.WriteLine(property.Key + ": " + property.Value);
}
// This code example produces the following output:
// Name: John Smith
// Age: 33

You are asking for dynamic ExpandoObject.
Example:
dynamic obj = new ExpandoObject();
obj.banana = "CIAO";
obj.bidshmqwq = 11245;
obj.BRUFCJMWH = null;
In substance, this Type can let you declare object's properties dynamically.

To convert from a json string to a C# object, you can use the DeserializeObject method and pass in an instance of the c# object that you want to convert this json to. The JsonConvert library is part of the Newtonsoft.Json library.
var converted = JsonConvert.DeserializeObject<myCSharpViewModel>(json);

Why is axios response in camel case when sending a request in asp.net core [duplicate]

I'm running through a WintellectNOW course on ASP.NET Core/Web API/Angular 2. I have the API portion implemented, but for whatever reason, the JSON that is being returned has the variable names being lowercased.
The returned JSON is formatted like...
[
{"id":1,"name":"Bowler","color":"black","count":1},
{"id":2,"name":"Fedora","color":"red","count":1},
{"id":3,"name":"Baseball Cap","color":"blue","count":3}
]
I'm expecting...
[
{"Id":1,"Name":"Bowler","Color":"black","Count":1},
{"Id":2,"Name":"Fedora","Color":"red","Count":1},
{"Id":3,"Name":"Baseball Cap","Color":"blue","Count":3}
]
Based on the C# model of...
namespace HatCollection.Models
{
public class Hat
{
public int Id { get; set; }
public string Name { get; set; }
public string Color { get; set; }
public int Count { get; set; }
}
}
I even went as far as decorating the properties with [DataMember(Name = "Id")] just to make sure and it still didn't matter.
On the off chance, it's relevant the Action and instance variable in the controller...
private static readonly List<Hat> MyHats = new List<Hat>
{
new Hat {Id = 1, Name = "Bowler", Color = "black", Count = 1 },
new Hat {Id = 2, Name = "Fedora", Color = "red", Count = 1 },
new Hat {Id = 3, Name = "Baseball Cap", Color = "blue", Count = 3 }
};
[HttpGet]
public IEnumerable<Hat> Get()
{
return MyHats;
}
How do I turn off the camelCase functionality, so that ASP.NET Core returns the property names without changing them?

In Asp.Net Core 3.0 some things have changed. For camelCase do nothing that is out of the box. For PascalCase or another set style use.
services.AddMvc(setupAction=> {
setupAction.EnableEndpointRouting = false;
}).AddJsonOptions(jsonOptions =>
{
jsonOptions.JsonSerializerOptions.PropertyNamingPolicy = null;
})
.SetCompatibilityVersion(CompatibilityVersion.Version_3_0);
In Startup.cs ConfigureServices section

For those who needs a solution about a PascalCase within Api Project that has not the Mvc services you should add this after AddControllers services
// This method gets called by the runtime. Use this method to add services to the container.
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers().AddJsonOptions(jsonOptions =>
{
jsonOptions.JsonSerializerOptions.PropertyNamingPolicy = null;
} ;
}

For Asp.Net Core 3.1 using the NewtonSoft.Json
services.AddControllers()
.AddNewtonsoftJson(options =>
{
options.UseMemberCasing();
});

In ASP.NET Core <3.0, JSON properties are camelCased by default (per this announcement).
You can disable this by replacing
services.AddMvc();
with
services
.AddMvc()
.AddJsonOptions(opt => opt.SerializerSettings.ContractResolver
= new DefaultContractResolver());
in your Startup.cs file. You'll have to add using Newtonsoft.Json.Serialization; to the top of the file.
With the DefaultContractResolver in place, the property names will be represented verbatim in the JSON output. No need for DataMember attributes.

Here is the answer for .net 5 :
https://learn.microsoft.com/en-us/aspnet/core/web-api/advanced/formatting?view=aspnetcore-5.0
Configure System.Text.Json based formatters Features for the
System.Text.Json based formatters can be configured using
Microsoft.AspNetCore.Mvc.JsonOptions.JsonSerializerOptions.
The
default formatting is camelCase. The following highlighted code sets
PascalCase formatting:
C#
public void ConfigureServices(IServiceCollection services)
{
services.AddControllers()
.AddJsonOptions(options =>
options.JsonSerializerOptions.PropertyNamingPolicy = null);
}

Another solution in Asp.Net.Core 2.2 as following:
services.AddMvc()
.AddJsonOptions(jsonOptions => jsonOptions.UseMemberCasing())
.SetCompatibilityVersion(CompatibilityVersion.Version_2_2);

In ASP.Net Core you can use two way:
First way: UseMemberCasing()
In StartUp.cs :
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews().AddNewtonsoftJson(opt =>
{
opt.UseMemberCasing(); // <-- add this
});
}
Second way: ContractResolver
In StartUp.cs :
public void ConfigureServices(IServiceCollection services)
{
services.AddControllersWithViews().AddNewtonsoftJson(opt =>
{
opt.SerializerSettings.ContractResolver = new DefaultContractResolver(); // <-- add this
});
}
depends on your project maybe you used AddMvc() or AddControllers() insted of AddControllersWithViews().
If AddNewtonsoftJson not found, you should install Nuget pacage : Microsoft.AspNetCore.Mvc.NewtonsoftJson (link).

You have to change the DefaultContractResolver which uses camelCase by default. Just set the NamingStatergy as null.
This should be done in the StartUp.ConfirgureService as follows.
public void ConfigureServices(IServiceCollection services)
{
services.AddMvc()
.AddMvcOptions(o => o.OutputFormatters.Add(
new XmlDataContractSerializerOutputFormatter()));
.AddJsonOptions(o => {
if (o.SerializerSettings.ContractResolver != null)
{
var castedResolver = o.SerializerSettings.ContractResolver
as DefaultContractResolver;
castedResolver.NamingStrategy = null;
}
});
}
Option 2
Use JSonProperty as follows.
public class Hat
{
[JsonProperty("id")]
public int Id { get; set; }
[JsonProperty("name")]
public string Name { get; set; }
[JsonProperty("color")]
public string Color { get; set; }
[JsonProperty("count")]
public int Count { get; set; }
}

I am using the following solution because
a) I prefer using the .Net Core built in System.Text.Json serializer and
b) I do not want to rely on the not documented internal behaviour of
jsonOptions.JsonSerializerOptions.PropertyNamingPolicy = null;.
.
services.AddControllers()
.AddJsonOptions(options =>
{
options.JsonSerializerOptions.PropertyNamingPolicy = new MyTransparentJsonNamingPolicy();
});
where:
public class MyTransparentJsonNamingPolicy : JsonNamingPolicy
{
// You can came up any custom transformation here, so instead just transparently
// pass through the original C# class property name, it is possible to explicit
// convert to PascalCase, etc:
public override string ConvertName(string name)
{
return name;
}
}

In .NET 6 I used:
builder.Services.AddControllersWithViews().AddJsonOptions(opt => opt.JsonSerializerOptions.PropertyNamingPolicy = null);

Error posting record to db asp.net mvc

I am building a scheduling system using fullcalendar for MVC, my get event retrieves from a view for a specific location.
However, my post / save event inserts into the table that the view is made from, containing all locations.
I am getting an error when I try to add the new event to the data connection.
"The field Location must be a string or array type with a maximum length of '1'." string
PropertyName "Location" string
I tried to set the string for the event manually before adding it to the data connection but this isn't working for some reason. Could it be me not declaring the string correctly?
//Actions for Calendar 5
public JsonResult GetEvents5()
{
using (CalgaryNEEntities dc = new CalgaryNEEntities())
{
var events = dc.CalgaryNEEvents.ToList();
return new JsonResult { Data = events, JsonRequestBehavior = JsonRequestBehavior.AllowGet };
}
}
[HttpPost]
public JsonResult SaveEvent5(EventsAllLocation e)
{
var status = false;
using (InsertEntities dc = new InsertEntities())
{
if (e.EventID > 0)
{
//Update the event
var v = dc.EventsAllLocations.Where(a => a.EventID == e.EventID).FirstOrDefault();
if (v != null)
{
var locationstring = "Calgary NE Kitchens";
v.CompanyName = e.CompanyName;
v.Start = e.Start;
v.End = e.End;
v.KitchenNumber = e.KitchenNumber;
v.Location = locationstring;
}
}
else
{
var locationstring = "Calgary NE Kitchens";
e.Location = locationstring;
dc.EventsAllLocations.Add(e);
}
dc.SaveChanges();
status = true;
}
return new JsonResult { Data = new { status = status } };
}
Here is the EventsAllLocation definition:
public partial class EventsAllLocation
{
public int EventID { get; set; }
public string Location { get; set; }
public string CompanyName { get; set; }
public System.DateTime Start { get; set; }
public Nullable<System.DateTime> End { get; set; }
public string KitchenNumber { get; set; }
}
Any tips or help would be greatly appreciated, thanks!

The answer is staring you in the face !! LOL
"The field Location must be a string or array type with a maximum
length of '1'." string PropertyName "Location" string

How to reuse code in EDGE.js (nodeJS .NET packet)

Ok, I'm currently working on UIAutomation with nodeJS and I'm using EDGE.js node module. All works fine (wow), but I have an issue with code re-usability.
I have few mostly identical functions that consist from the same code for more than 50%. Of course I want to move this code to a single place, but problem is that this code placed in js comments (EDGE stuff).
How can I reuse my code to avoid repetitions in EDGE.js?
Yeah.. as a last resort I can put everything into one c# "program" and call different c# functions depending on arguments, but probably there is a way to keep several js functions? Thanks!
Here is an example of 2 functions. I want to keep different only "public async Task" part at the bottom of each block. Any ideas?
BTW: Any suggestions about C# code are also welcome! Cause I'm pretty sure, that it's total crap ^^
getWindows: function() {
/*
using System;
using System.Windows;
using System.Windows.Automation;
using System.Threading.Tasks;
using System.Collections.Generic;
public class myRect
{
public int width { get; set; }
public int height { get; set; }
public int top { get; set; }
public int left { get; set; }
public myRect( AutomationElement el ) {
System.Windows.Rect r = (System.Windows.Rect)(
el.GetCurrentPropertyValue(
AutomationElement.BoundingRectangleProperty,
true));
width = (int)r.Width;
height = (int)r.Height;
top = (int)r.Top;
left = (int)r.Left;
}
}
public class Winfo
{
public string name { get; set; }
public string automationId { get; set; }
public int processId { get; set; }
public myRect window { get; set; }
public myRect browser { get; set; }
}
public class Startup {
private Winfo getWinInfo( AutomationElement el ) {
if ( el == null ) return( null );
Winfo winfo = new Winfo {
name = el.Current.Name,
automationId = el.Current.AutomationId,
processId = el.Current.ProcessId,
window = new myRect(el)
};
try {
var tmpWeb = el
.FindFirst( TreeScope.Descendants,
new PropertyCondition(
AutomationElement.ClassNameProperty,
"CefBrowserWindow") )
.FindFirst( TreeScope.Descendants,
new PropertyCondition(
AutomationElement.NameProperty,
"Chrome Legacy Window"));
winfo.browser = new myRect(tmpWeb);
} catch { winfo.browser = null; }
return(winfo);
}
public async Task<object> Invoke(dynamic input) {
var els = AutomationElement.RootElement.FindAll(
TreeScope.Children,
Condition.TrueCondition);
List<Winfo> windowList = new List<Winfo>{};
bool all;
try { all = (bool)input.all; } catch { all = false; };
foreach (AutomationElement el in els) {
Winfo winfo = getWinInfo(el);
if ((winfo!=null) && (all || (winfo.browser!=null))) {
windowList.Add( winfo );
}
}
return(windowList);
}
}
*/
}
And another one
waitWindow: function() {
/*
using System;
using System.Windows;
using System.ComponentModel;
using System.Windows.Automation;
using System.Threading.Tasks;
using System.Threading;
using System.Collections.Generic;
public class myRect {
public int width { get; set; }
public int height { get; set; }
public int top { get; set; }
public int left { get; set; }
public myRect( AutomationElement el ) {
System.Windows.Rect r = (System.Windows.Rect)(
el.GetCurrentPropertyValue(
AutomationElement.BoundingRectangleProperty,
true));
width = (int)r.Width;
height = (int)r.Height;
top = (int)r.Top;
left = (int)r.Left;
}
}
public class Winfo
{
public string name { get; set; }
public string automationId { get; set; }
public int processId { get; set; }
public myRect window { get; set; }
public myRect browser { get; set; }
}
public class Startup {
private static AutoResetEvent waitHandle;
private Winfo getWinInfo( AutomationElement el ) {
if ( el == null ) return( null );
Winfo winfo = new Winfo {
name = el.Current.Name,
automationId = el.Current.AutomationId,
processId = el.Current.ProcessId,
window = new myRect(el)
};
try {
var tmpWeb = el
.FindFirst( TreeScope.Descendants,
new PropertyCondition(
AutomationElement.ClassNameProperty,
"CefBrowserWindow") )
.FindFirst( TreeScope.Descendants,
new PropertyCondition(
AutomationElement.NameProperty,
"Chrome Legacy Window"));
winfo.browser = new myRect(tmpWeb);
} catch { winfo.browser = null; }
return(winfo);
}
public async Task<object> Invoke(dynamic input) {
int t;
try { t = (int)input.timeout; } catch { t = 0; };
string wname;
try { wname = (string)input.name; } catch { wname = ""; };
AutomationElement el = AutomationElement.RootElement.FindFirst(
TreeScope.Children,
new PropertyCondition( AutomationElement.NameProperty, wname ));
if ( el == null ) {
waitHandle = new AutoResetEvent(false);
Automation.AddAutomationEventHandler(
WindowPattern.WindowOpenedEvent,
AutomationElement.RootElement,
TreeScope.Children,
(sender, e) => {
var obj = sender as AutomationElement;
if (obj.Current.Name == wname) {
el = obj;
waitHandle.Set();
}
}
);
waitHandle.WaitOne(t);
Automation.RemoveAllEventHandlers();
}
return( getWinInfo(el) );
}
}
*/
}
};

You can split the reusable C# code into separate multi-line javascript strings, using the same technique that edgejs uses.
Below is a simple example where a function has been broken into two separate variables, Line1 and Line2. You could split your code into multiple functions/variables that contains the re-usable code and then build your code by concatenating the individual bits.
var edge = require('edge');
function getMultilineString(fn){
return (fn).toString().match(/[^]*\/\*([^]*)\*\/\}$/)[1];
}
var line1 = getMultilineString(function () {/*
async (input) => {
*/});
var line2 = getMultilineString(function () {/*
return ".NET welcomes " + input.ToString();
}
*/});
//var hello = edge.func(function () {/*
// async (input) => {
// return ".NET welcomes " + input.ToString();
// }
//*/});
var hello = edge.func(line1 + line2);
hello('Node.js', function (error, result) {
if (error) throw error;
console.log(result);
});