Microsoft.Net Developer

Xamarin : How to call API POST method

Xamarin : API call

How to consume API method in xamarin application ?

I tried on google but couldn't find proper example. I got help of my friend who have knowledge of xamarin and some help from google, and created successful demo, which I am sharing with you.

Steps:

First check that API is working or not
Install "newtonsoft json" from NuGet package manager

Design

<Grid>

<Grid.RowDefinitions>

</Grid.RowDefinitions>

<Grid.ColumnDefinitions>

</Grid.ColumnDefinitions>

<Button Text="Get Data"

Clicked="OnGetDataButtonClicked"

Grid.Row="0"

Grid.Column="0"></Button>

<Label x:Name="lblMsg"

Grid.Row="1"

Grid.Column="0"></Label>

<ListView.ItemTemplate>

</StackLayout>

</ViewCell>

</DataTemplate>

</ListView.ItemTemplate>

</ListView>

</Grid>

Code

async void OnGetDataButtonClicked(object sender, EventArgs e)

{

try

{

HttpClient client = new HttpClient();

string requestPayload = @"{

""UserId"": ""123"",

""dataTableCommon"":{

""param"" :{""Start"": ""21"",

""Length"": ""10"",

""Draw"" :""1""}

}

}";

var response = await client.PostAsync("http://Domainname/DemoAPI/API/User/GetUsersList",

new StringContent(requestPayload, Encoding.UTF8, "application/json"));

if (response.StatusCode == HttpStatusCode.OK)

{

var json = await response.Content.ReadAsStringAsync();

//Here you need to create class for output results

// To generate class, you can use http://json2csharp.com

var results = JsonConvert.DeserializeObject<RootObject>(json);

MainList.ItemsSource = results.data;

}

catch (Exception ex)

{

lblMsg.Text = ex.Message;

}

void OnTapped(object sender, ItemTappedEventArgs e)

{

var selected = e.Item as Users;

DisplayAlert("Name", selected.FirstName + " " + selected.LastName, "Okay");

}

Generate Class

// To generate class, you can use http://json2csharp.com

public class Users

{

public string UserId { get; set; }

public string FirstName { get; set; }

public string LastName { get; set; }

public string EmailId { get; set; }

}

public class RootObject

{

public List<Users> data { get; set; }

}

Output

I hope, you like the article !!! ENJOY !!!

Xamarin : Resource Contents - Stylesheet

Design Page

<ContentPage.Resources>

</Style>

</Style>

</Style>

</ResourceDictionary>

</ContentPage.Resources>

<Label Text="Different color"

Style="{StaticResource ColorfullLabel}"></Label>

<Label Text="Font Size"

FontSize="20"></Label>

<Label Text="Margin"

Style="{StaticResource lblMargin}"></Label>

<Label Text="Italic"

FontAttributes="Italic"></Label>

<Label Text="Left Justified"

HorizontalTextAlignment="End"

FontSize="Large"></Label>

<Label Text="Hello, World!"

VerticalOptions="Start"

HorizontalTextAlignment="Center"

Rotation="-15"

IsVisible="true"

FontSize="Large"

FontAttributes="Bold"

TextColor="Blue" />

<Button Text="Verticle Button"

Style="{StaticResource btnMargin}">

</Button>

</StackLayout>

Xamarin : Button Formatting & Click Event

Design

<Button Text="Different color"

TextColor="Yellow"

BackgroundColor="Blue"></Button>

<Button Text="Font Size"

FontSize="20">

</Button>

<Button Text="Margin"

Margin="20"></Button>

<Button Text="Center"

HorizontalOptions="Center"

VerticalOptions="Center">

</Button>

<Button Text="Verticle Button"

Rotation="20"

BorderWidth="20" Clicked="btnClick">

</Button>

</StackLayout>

Code:

void btnClick(object sender, EventArgs e)

{

DisplayAlert("Button Click", "You clicked on button :)", "Okay");

}

Xamarin : Label Formatting

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="App1.NewPage"
Title="Label Formatting">

<StackLayout Orientation="Vertical">

<Label Text="Different color"
TextColor="Red"
BackgroundColor="Yellow"></Label>

<Label Text="Font Size"
FontSize="20"></Label>

<Label Text="Margin"
Margin="20"></Label>

<Label Text="Italic"
FontAttributes="Italic"></Label>

<Label Text="Left Justified"
HorizontalTextAlignment="End"
FontSize="Large"></Label>

<Label Text="Hello, World!"
VerticalOptions="Start"
HorizontalTextAlignment="Center"
Rotation="-15"
IsVisible="true"
FontSize="Large"
FontAttributes="Bold"
TextColor="Blue" />

</StackLayout>

</ContentPage>

Run the application

Xamarin : OnTapped navigation to new page

Add listview in page

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="App1.MainMaster"
Title="My Application">
  <ListView x:Name="MainList" ItemTapped="OnTapped">
<ListView.ItemTemplate>
  <DataTemplate>
<ViewCell>
  <StackLayout Orientation="Horizontal">
<Label Text="{Binding Name}"></Label>
<Label Text="{Binding Description}"></Label>
<Label Text="{Binding OrderNumber}"></Label>
  </StackLayout>
</ViewCell>
  </DataTemplate>
</ListView.ItemTemplate>
  </ListView>
</ContentPage>

Write a code to bind listview

public partial class MainMaster : ContentPage
{
public MainMaster()
{
InitializeComponent();
MainList.ItemsSource = new List<ListViewTemplate>
{
new ListViewTemplate { Name="One", Description="One", OrderNumber=1 },
new ListViewTemplate { Name="Two", Description="Two", OrderNumber=2 },
new ListViewTemplate { Name="Three", Description="Three", OrderNumber=3 }, new ListViewTemplate { Name="Four", Description="Four", OrderNumber=4 },
new ListViewTemplate { Name="Five", Description="Five", OrderNumber=5 },
};
}
}

Add new page, I set name "NewPage"

async void OnTapped(object sender, ItemTappedEventArgs e)
{
var selected = e.Item as ListViewTemplate;

switch (selected.OrderNumber)
{
case 1:
await Navigation.PushAsync(new NewPage());
break;
case 2:
break;
case 3:
break;
case 4:
break;
case 5:
break;
}

//Set not to selected item : optional
((ListView)sender).SelectedItem = null;
}

Set page in to run the application

public class App : Application
{
public App()
{
MainPage = new NavigationPage(new MainMaster());
}

}

Run the application

Xamarin : OnTapped (on clicked) item in listview

Add listview in page

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="App1.MainMaster"
Title="My Application">
  <ListView x:Name="MainList" ItemTapped="OnTapped">
<ListView.ItemTemplate>
  <DataTemplate>
<ViewCell>
  <StackLayout Orientation="Horizontal">
<Label Text="{Binding Name}"></Label>
<Label Text="{Binding Description}"></Label>
<Label Text="{Binding OrderNumber}"></Label>
  </StackLayout>
</ViewCell>
  </DataTemplate>
</ListView.ItemTemplate>
  </ListView>
</ContentPage>

Write a code to bind listview

Set page in to run the application

public class App : Application
{
public App()
{
MainPage = new MainMaster();
}

}

Run the application

Xamarin : Create simple List

Create new page

Create new class for listing properties

public class ListViewTemplate

{

public string Name { get; set; }

public string Description { get; set; }

public int OrderNumber { get; set; }

}

Add listview in page

<?xml version="1.0" encoding="utf-8" ?>
<ContentPage xmlns="http://xamarin.com/schemas/2014/forms"
xmlns:x="http://schemas.microsoft.com/winfx/2009/xaml"
x:Class="App1.MainMaster"
Title="My Application">
<ListView x:Name="MainList">
<ListView.ItemTemplate>
<DataTemplate>
<ViewCell>
<StackLayout Orientation="Horizontal">
<Label Text="{Binding Name}"></Label>
<Label Text="{Binding Description}"></Label>
<Label Text="{Binding OrderNumber}"></Label>
</StackLayout>
</ViewCell>
</DataTemplate>
</ListView.ItemTemplate>
</ListView>
</ContentPage>

Write a code to bind listview

Set page in to run the application

public class App : Application
{
public App()
{
MainPage = new MainMaster();
}

}

Run the application