问题描述
我创建的Web API从SQL数据库检索数据。我需要使用Web API中xamrin Android和xamarin为iOS。截至目前xamarin为Android。我不知道如何调用GET和POST方法的基础上的按钮单击事件。
下面是网络API
使用系统;
使用System.Collections.Generic;
使用System.Linq的;
使用System.Net;
使用System.Net.Http;
使用System.Web.Http;
命名空间MvcAppDept.Controllers
{
公共类DeptController:ApiController
{
//获取API /值
公开的IEnumerable<部>得到()
{
AndroidAppDBEntities DB =新AndroidAppDBEntities();
VAR数据部门在db.Depts =排序依据dept.no选择部门;
返回data.ToList();
}
//获取API /价值/ 5
公共部门获取(INT ID)
{
AndroidAppDBEntities DB =新AndroidAppDBEntities();
VAR数据=从部门在db.Depts那里dept.no == ID选择部门;
返回data.SingleOrDefault();
}
// POST API /值
公共无效后(部OBJ)
{
AndroidAppDBEntities DB =新AndroidAppDBEntities();
db.Depts.Add(OBJ);
db.SaveChanges();
}
// PUT API /价值/ 5
公共无效认沽(INT ID,部门OBJ)
{
AndroidAppDBEntities DB =新AndroidAppDBEntities();
VAR数据=从部门在db.Depts那里dept.no == ID选择部门;
部旧= data.SingleOrDefault();
old.no = obj.no;
old.name = obj.name;
db.SaveChanges();
}
//删除API /价值/ 5
公共无效删除(INT ID)
{
AndroidAppDBEntities DB =新AndroidAppDBEntities();
VAR数据=从部门在db.Depts那里dept.no == ID选择部门;
部OBJ = data.SingleOrDefault();
db.Depts.Remove(OBJ);
db.SaveChanges();
}
}
}
的Global.asax.cs
使用系统;
使用System.Collections.Generic;
使用System.Linq的;
使用的System.Web;
使用System.Web.Http;
使用System.Web.Mvc;
使用System.Web.Optimization;
使用System.Web.Routing;
命名空间MvcAppDept
{
公共类WebApiApplication:System.Web.HttpApplication
{
保护无效的Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
}
}
}
MainActivity.cs
使用系统;
使用System.Net.Http;
使用System.Threading.Tasks;
使用Android.App;
使用Android.Content;
使用Android.Runtime;
使用Android.Views;
使用Android.Widget;
使用Android.OS;
命名空间DeptAndroidApp
{
[活动(标签=DeptAndroidApp,MainLauncher = TRUE,图标=@可绘制/图标)]
公共类MainActivity:活动
{
保护覆盖无效的OnCreate(束捆)
{
base.OnCreate(包);
的setContentView(Resource.Layout.Main);
按钮GetButton = FindViewById<按钮>(Resource.Id.GetButton);
VAR txtValue1 = FindViewById<的EditText>(Resource.Id.txtValue1);
INT ID = Convert.ToInt32(txtValue1.Text);
无功无= FindViewById< TextView的>(Resource.Id.No);
VAR名称= FindViewById< TextView的>(Resource.Id.Name);
//GetButton.Click + = GetDept(ID);
GetButton.Click + =异步(发件人,参数)=> {
//错误不能等待DeptAndroidApp.dept
部部=等待GetDept(ID);
No.Text = dept.No;
Name.Text = dept.name}
}
//错误的返回类型ofasync方法必须是无效的,任务orTask< T>
公共异步部门GetDept(INT ID)
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://****.***/);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(新System.Net.Http.Headers.MediaTypeWithQualityHeaderValue(应用/ JSON));
VAR的结果=等待client.GetAsync(的String.Format(/ API /部门/ {0},ID));
返回JsonConvert.DeserializeObject<部>(等待result.Content.ReadAsStringAsync()); }
}
}
}
下面是我会怎么使用这项服务从几乎任何项目(包括Xamarin项目)。
首先,摆脱线在Global.asax文件,上面写着这样的:
GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
一般来说,这是不好的做法。你想拥有至少XML和JSON格式化用,因为在一个宁静的环境,它是由消费者来决定他们需要什么类型的系列化/想要的。
接下来,我会使用 System.Net.Http.HttpClient
类与这个服务进行交互。
从这个点上的Web API服务的交互是相当简单的。下面是一些例子。
公共异步名单,其中,部> GetDepts()
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://< ip地址:端口> /);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(新MediaTypeWithQualityHeaderValue(应用/ JSON));
返回等待client.GetAsync(/ API /部门);
}
}
公共异步任务<部> GetDept(INT ID)
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://< ip地址:端口> /);
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(新MediaTypeWithQualityHeaderValue(应用/ JSON));
VAR的结果=等待client.GetAsync(的String.Format(/ API /部门/ {0},ID));
返回JsonConvert.DeserializeObject<部>(等待result.Content.ReadAsStringAsync());
}
}
公共异步任务AddDept(系部)
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://< ip地址:端口> /);
等待client.PostAsJsonAsync(/ API /部门,部门);
}
}
公共异步任务UpdateDept(系部)
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://< ip地址:端口> /);
等待client.PutAsJsonAsync(的String.Format(/ API /部门/ {0},dept.no),部门);
}
}
公共异步任务DeleteDept(INT ID)
{
使用(VAR的客户=新的HttpClient())
{
client.BaseAddress =新的URI(HTTP://< ip地址:端口> /);
client.DeleteAsync(的String.Format(/ API /部门/ {0},ID));
}
}
这应该让你在正确的方向开始呢。这肯定可以得到清理和我写的写意所以有可能会出现一些错别字。
更新的
更新您的MainActivity.cs
而不是内部ID = Convert.ToInt32(txtValue1)
使用
内部ID = Convert.ToInt32(txtValue1.Text);
而不是 GetButton.Click + = GetDept(ID)的;
使用
GetButton.Click + =异步(发件人,参数)=> {
VAR部门=等待GetDept(ID);
No.Text = dept.no;
Name.Text = dept.name
}
I have created web api that retrieves data from SQL database. I need to consume web api in xamrin for android and xamarin for iOS. as of now xamarin for android. I am not sure how to call GET and Post method based on button click event.
Here is web api
using System;
using System.Collections.Generic;
using System.Linq;
using System.Net;
using System.Net.Http;
using System.Web.Http;
namespace MvcAppDept.Controllers
{
public class DeptController : ApiController
{
// GET api/values
public IEnumerable<Dept> Get()
{
AndroidAppDBEntities db = new AndroidAppDBEntities();
var data = from dept in db.Depts orderby dept.no select dept;
return data.ToList();
}
// GET api/values/5
public Dept Get(int id)
{
AndroidAppDBEntities db = new AndroidAppDBEntities();
var data = from dept in db.Depts where dept.no == id select dept;
return data.SingleOrDefault();
}
// POST api/values
public void Post(Dept obj)
{
AndroidAppDBEntities db = new AndroidAppDBEntities();
db.Depts.Add(obj);
db.SaveChanges();
}
// PUT api/values/5
public void Put(int id,Dept obj)
{
AndroidAppDBEntities db = new AndroidAppDBEntities();
var data = from dept in db.Depts where dept.no == id select dept;
Dept old = data.SingleOrDefault();
old.no = obj.no;
old.name = obj.name;
db.SaveChanges();
}
// DELETE api/values/5
public void Delete(int id)
{
AndroidAppDBEntities db = new AndroidAppDBEntities();
var data = from dept in db.Depts where dept.no == id select dept;
Dept obj = data.SingleOrDefault();
db.Depts.Remove(obj);
db.SaveChanges();
}
}
}
Global.asax.cs
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Http;
using System.Web.Mvc;
using System.Web.Optimization;
using System.Web.Routing;
namespace MvcAppDept
{
public class WebApiApplication : System.Web.HttpApplication
{
protected void Application_Start()
{
AreaRegistration.RegisterAllAreas();
WebApiConfig.Register(GlobalConfiguration.Configuration);
FilterConfig.RegisterGlobalFilters(GlobalFilters.Filters);
RouteConfig.RegisterRoutes(RouteTable.Routes);
BundleConfig.RegisterBundles(BundleTable.Bundles);
GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
}
}
}
MainActivity.cs
using System;
using System.Net.Http;
using System.Threading.Tasks;
using Android.App;
using Android.Content;
using Android.Runtime;
using Android.Views;
using Android.Widget;
using Android.OS;
namespace DeptAndroidApp
{
[Activity(Label = "DeptAndroidApp", MainLauncher = true, Icon = "@drawable/icon")]
public class MainActivity : Activity
{
protected override void OnCreate(Bundle bundle)
{
base.OnCreate(bundle);
SetContentView(Resource.Layout.Main);
Button GetButton = FindViewById<Button>(Resource.Id.GetButton);
var txtValue1 = FindViewById<EditText>(Resource.Id.txtValue1);
int id = Convert.ToInt32(txtValue1.Text);
var No = FindViewById<TextView>(Resource.Id.No);
var Name = FindViewById<TextView>(Resource.Id.Name);
//GetButton.Click += GetDept(id);
GetButton.Click+=async(sender,args)=>{
//error Cannot await 'DeptAndroidApp.dept
Dept dept=await GetDept(id);
No.Text=dept.No;
Name.Text=dept.name}
}
//Error The return type ofasync method must be void,task orTask<T>
public async Dept GetDept(int id)
{
using (var client = new HttpClient())
{
client.BaseAddress = new Uri("http://****.***/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new System.Net.Http.Headers.MediaTypeWithQualityHeaderValue("application/json"));
var result= await client.GetAsync(string.Format("/api/dept/{0}",id));
return JsonConvert.DeserializeObject<Dept>(await result.Content.ReadAsStringAsync()); }
}
}
}
Here is how I would use this service from just about any project (including Xamarin projects).
First, get rid of the line in your Global.asax file that says this:
GlobalConfiguration.Configuration.Formatters.XmlFormatter.SupportedMediaTypes.Clear();
Generally speaking this is bad practice. You want to have at least the XML and JSON formatters available because in a restful environment it is up to the consumers to determine what type of serialization they need/want.
Next, I would use the System.Net.Http.HttpClient
class to interact with this service.
Interacting with the Web Api service from this point is fairly straightforward. Here are some examples.
public async List<Dept> GetDepts()
{
using(var client = new HttpClient())
{
client.BaseAddress = new Uri("http://<ipAddress:port>/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
return await client.GetAsync("/api/dept");
}
}
public async Task<Dept> GetDept(int id)
{
using(var client = new HttpClient())
{
client.BaseAddress = new Uri("http://<ipAddress:port>/");
client.DefaultRequestHeaders.Accept.Clear();
client.DefaultRequestHeaders.Accept.Add(new MediaTypeWithQualityHeaderValue("application/json"));
var result = await client.GetAsync(string.format("/api/dept/{0}", id));
return JsonConvert.DeserializeObject<Dept>(await result.Content.ReadAsStringAsync());
}
}
public async Task AddDept(Dept dept)
{
using(var client = new HttpClient())
{
client.BaseAddress = new Uri("http://<ipAddress:port>/");
await client.PostAsJsonAsync("/api/dept", dept);
}
}
public async Task UpdateDept(Dept dept)
{
using(var client = new HttpClient())
{
client.BaseAddress = new Uri("http://<ipAddress:port>/");
await client.PutAsJsonAsync(string.format("/api/dept/{0}", dept.no), dept);
}
}
public async Task DeleteDept(int id)
{
using(var client = new HttpClient())
{
client.BaseAddress = new Uri("http://<ipAddress:port>/");
client.DeleteAsync(string.format("/api/dept/{0}", id));
}
}
That should get you started in the right direction anyway. This could definitely get cleaned up and I wrote it freehand so there may be some typos.
Update
Update your MainActivity.cs
Instead of int id = Convert.ToInt32(txtValue1)
Use
int id = Convert.ToInt32(txtValue1.Text);
Instead of GetButton.Click += GetDept(id);
Use
GetButton.Click += async (sender, args) => {
var dept = await GetDept(id);
No.Text = dept.no;
Name.Text = dept.name
}
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