Xamarin Form Date Format on XAML Page

<Label Text="{Binding Date,StringFormat='{0:MM/dd/yy}'}" />  

Output: 05/25/2019


Date Formats:

DateTime.Now.ToString("MM/dd/yyyy")	05/29/2015
DateTime.Now.ToString("dddd, dd MMMM yyyy")	Friday, 29 May 2015
DateTime.Now.ToString("dddd, dd MMMM yyyy")	Friday, 29 May 2015 05:50
DateTime.Now.ToString("dddd, dd MMMM yyyy")	Friday, 29 May 2015 05:50 AM
DateTime.Now.ToString("dddd, dd MMMM yyyy")	Friday, 29 May 2015 5:50
DateTime.Now.ToString("dddd, dd MMMM yyyy")	Friday, 29 May 2015 5:50 AM
DateTime.Now.ToString("dddd, dd MMMM yyyy HH:mm:ss")	Friday, 29 May 2015 05:50:06
DateTime.Now.ToString("MM/dd/yyyy HH:mm")	05/29/2015 05:50
DateTime.Now.ToString("MM/dd/yyyy hh:mm tt")	05/29/2015 05:50 AM
DateTime.Now.ToString("MM/dd/yyyy H:mm")	05/29/2015 5:50
DateTime.Now.ToString("MM/dd/yyyy h:mm tt")	05/29/2015 5:50 AM
DateTime.Now.ToString("MM/dd/yyyy HH:mm:ss")	05/29/2015 05:50:06
DateTime.Now.ToString("MMMM dd")	May 29
DateTime.Now.ToString("yyyy’-‘MM’-‘dd’T’HH’:’mm’:’ss.fffffffK")	2015-05-16T05:50:06.7199222-04:00
DateTime.Now.ToString("ddd, dd MMM yyy HH’:’mm’:’ss ‘GMT’")	Fri, 16 May 2015 05:50:06 GMT
DateTime.Now.ToString("yyyy’-‘MM’-‘dd’T’HH’:’mm’:’ss")	2015-05-16T05:50:06
DateTime.Now.ToString("HH:mm")	05:50
DateTime.Now.ToString("hh:mm tt")	05:50 AM
DateTime.Now.ToString("H:mm")	5:50
DateTime.Now.ToString("h:mm tt")	5:50 AM
DateTime.Now.ToString("HH:mm:ss")	05:50:06
DateTime.Now.ToString("yyyy MMMM")	2015 May

For more details about date format, you can visit this link 

https://www.c-sharpcorner.com/blogs/date-and-time-format-in-c-sharp-programming1

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Handling Single Object and Multiple Object JSON Converter

Deserializing Single Object and Multiple Object using JSON Converter.

JSON Sample
this is Single Json Object 

{
 "Name":"Test",
 "Email":"Abc",
 "ID":1
}     

Multi Json Object

[
   {
     "Name": "Test",
     "Email": "Abc",
     "ID": 1
   },
   {
     "Name": "Test1",
     "Email": "Abc1",
     "ID": 2
   }
]

List<Employee> list = JsonConvert.DeserializeObject<List<Employee>>("string json Content");

Here if your JSON string contain single object that time it cause error like "'Cannot deserialize the current JSON object (e.g. {"name":"value"}) into type 'System.Collections.Generic.List'."

so to avoid this use the JSON Converter.

Example: 

JsonSerializerSettings setting = new JsonSerializerSettings();
setting.Converters.Add(new SingleOrArrayConverter<Employee>());
 
List<Employee> list = JsonConvert.DeserializeObject<List<Employee>>("string json Content",setting);

Custom Class For Converting Object Result into JSON

Public class SingleOrArrayConverter<T> : JsonConverter
{
     public override bool CanConvert(Type objectType)
     {
         return (objectType == typeof(List<T>));
     }
     public override object ReadJson(JsonReader reader, Type objectType, object existingValue, JsonSerializer serializer)
     {
         JToken token = JToken.Load(reader);
         if (token.Type == JTokenType.Array)
         {
             return token.ToObject<List<T>>();
         }
         return new List<T> { token.ToObject<T>() };
 
     }
     public override bool CanWrite
     {
         get { return false; }
     }
     public override void WriteJson(JsonWriter writer, object value, JsonSerializer serializer)
     {
         throw new NotImplementedException();
     }
 
}

Convert XML To Json with NULL Value Handling, Remove Empty Element from XML Node

Convert XML To Json with NULL Value Handling

XDocument doc = XDocument.Parse("Specify the XML Content in String Format");
 
doc.Descendants().Where(f => f.IsEmpty || string.IsNullOrWhiteSpace(f.Value)).Remove();
 
string jsonText = JsonConvert.SerializeXNode(doc); // this will convert XNode to Json Text

Namespaces used

using System.Xml.Linq;
using Newtonsoft.Json;
using System.Linq; 

Xamarin Forms Trigger (Data Trigger, Property Trigger)

Property Trigger 

Property triggers occur when a property on control is set to a particular value.

Page1.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:d="http://xamarin.com/schemas/2014/forms/design"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             x:Class="TestAppDemo.Page1">
    <ContentPage.Content>
        <StackLayout Margin="10">
            <Label Text="Property Trigger" FontSize="Large" />
            <Entry Placeholder="Enter Text">
                <Entry.Triggers>
                    <Trigger TargetType="Entry" Property="IsFocused" Value="True">
                        <Setter Property="BackgroundColor" Value="LightBlue" />
                    </Trigger>
                </Entry.Triggers>
            </Entry>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>

Data Trigger 

Data triggers occur when a property of other control is set. And also you can specify the binding from ViewModel.

Page1.xaml

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
             xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
             xmlns:d="http://xamarin.com/schemas/2014/forms/design"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             mc:Ignorable="d"
             x:Class="TestAppDemo.Page1">
    <ContentPage.Content>
        <StackLayout Margin="10">
            <Label Text="Data Trigger" FontSize="Large" />
            <StackLayout Orientation="Horizontal">
                <CheckBox x:Name="chkBox"   />
                <Label Text="IsCheckbox checked" VerticalTextAlignment="Center"  >
                    <Label.Triggers>
                        <DataTrigger TargetType="Label" Binding="{Binding Source={x:Reference chkBox},Path=IsChecked }" Value="True" >
                            <Setter Property="Text" Value="Yes!" />
                        </DataTrigger>
                        <DataTrigger TargetType="Label" Binding="{Binding Source={x:Reference chkBox},Path=IsChecked }" Value="False" >
                            <Setter Property="Text" Value="No!" />
                        </DataTrigger>
                    </Label.Triggers>
                </Label>
            </StackLayout>
        </StackLayout>
    </ContentPage.Content>
</ContentPage>
 

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Deep Cloning of Object in Xamarin - C#

Using newtonsoft json you can achieve deep cloning easily.

var serialized = JsonConvert.SerializeObject(AnyObject);
var deserializedObject JsonConvert.DeserializeObject<TypeOfObject>(serialized);

Sample

List<Employee> emp= new List<Employee>();
List<Employee> emp1 = new List<Employee>();
emp1=emp;

 Now if you update the emp1 data it reflect the emp object too.
 for avoid this you can use object cloning.

 var serialized = JsonConvert.SerializeObject(emp);
 var deserializedObject = JsonConvert.DeserializeObject<List<Employee>>(serialized);

Top 60 Xamarin Blog 

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