gCgY3dja

1using System;
2using System.Collections.Generic;
3using System.Collections.Specialized;
4using System.ComponentModel;
5using System.Data;
6using System.Drawing;
7using System.Linq;
8using System.Net;
9using System.Text;
10using System.Threading.Tasks;
11using System.Windows.Forms;
12using static System.Windows.Forms.ListViewItem;
13
14namespace Client
15{
16    /**
17     * Progetto: creare un client che permetta l'esecuzione dei metodi HTTP CRUD (Get, Post, Put, Delete) su una web API utilizzando metodi Asincroni 
18     * e premettendo l'autenticazione e con una piccola gestione degli errori
19     * L'app si può provare sui siti https://jsonplaceholder.typicode.com/ e https://dummy.restapiexample.com/
20     */
21    public partial class Form1 : Form
22    {
23        private ICredentials credentials = new NetworkCredential();
24
25        public Form1()
26        {
27            InitializeComponent();
28        }
29
30        private void Form1_Load(object sender, EventArgs e)
31        {
32
33        }
34
35        private async void Get(string url)
36        {
37            using (var client = new WebClient())
38            {
39                client.Credentials = credentials;
40                foreach (ListViewItem item in lstQuery.Items)
41                {
42                    client.QueryString.Add(item.SubItems[0].Text, item.SubItems[1].Text);
43                }
44                try
45                {
46                    var result = await client.DownloadStringTaskAsync(new Uri(url));
47                    txtOutput.Text = result;
48                }
49                catch (WebException e)
50                {
51                    HandleException(e);
52                }
53            }
54        }
55
56        private async void ExecuteMethod(string method, string url)
57        {
58            var values = new NameValueCollection();
59            using (var client = new WebClient())
60            {
61                client.Credentials = credentials;
62                foreach (ListViewItem item in lstQuery.Items)
63                {
64                    values.Add(item.SubItems[0].Text, item.SubItems[1].Text);
65                }
66                try
67                {
68                    var response = await client.UploadValuesTaskAsync(url, method, values);
69                    txtOutput.Text = Encoding.ASCII.GetString(response);
70                }
71                catch (WebException e)
72                {
73                    HandleException(e);
74                }
75            }
76        }
77
78        private void HandleException(WebException exception)
79        {
80            if (exception.Status == WebExceptionStatus.ProtocolError)
81            {
82                MessageBox.Show("Errore, status code: " + ((HttpWebResponse)exception.Response).StatusCode);
83            }
84            else if (exception.Status == WebExceptionStatus.Timeout)
85                MessageBox.Show("Errore: timeout");
86            else if (exception.Status == WebExceptionStatus.ConnectFailure)
87                MessageBox.Show("Connessione fallita");
88            else
89                MessageBox.Show("Errore: " + exception.ToString());
90        }
91
92        private void btnAdd_Click(object sender, EventArgs e)
93        {
94            var key = txtKey.Text;
95            var value = txtValue.Text;
96            lstQuery.Items.Add(new ListViewItem(new string[] { key, value }));
97        }
98
99        private void btnGet_Click(object sender, EventArgs e)
100        {
101            Get(txtUrl.Text);
102        }
103
104        private void btnPost_Click(object sender, EventArgs e)
105        {
106            ExecuteMethod("POST", txtUrl.Text);
107        }
108
109        private void btnPut_Click(object sender, EventArgs e)
110        {
111            ExecuteMethod("PUT", txtUrl.Text);
112        }
113
114        private void btnDelete_Click(object sender, EventArgs e)
115        {
116            ExecuteMethod("DELETE", txtUrl.Text);
117        }
118
119        private void btnClear_Click(object sender, EventArgs e)
120        {
121            txtOutput.Text = "";
122        }
123
124        private void btnGetSync_Click(object sender, EventArgs e)
125        {
126            using (var client = new WebClient())
127            {
128                foreach (ListViewItem item in lstQuery.Items)
129                {
130                    client.QueryString.Add(item.SubItems[0].Text, item.SubItems[1].Text);
131                }
132                try
133                {
134                    var result = client.DownloadString(txtUrl.Text);
135                    txtOutput.Text = result;
136                }
137                catch (WebException exc)
138                {
139                    HandleException(exc);
140                }
141            }
142        }
143
144        private void btnSet_Click(object sender, EventArgs e)
145        {
146            this.credentials = new NetworkCredential(txtUsername.Text, txtPassword.Text);
147        }
148    }
149}