add update checker (from Settings tab, Check Updates button), add prebuild event script to fetch latest release into PreviousVersion.txt file, fix missing status label

Author: unitycoder

Diff for: UnityLauncher/Form1.Designer.cs

@@ -6,6 +6,7 @@
 using System.IO;
 using System.Linq;
 using System.Net;
+using System.Reflection;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Windows.Forms;
@@ -17,8 +18,12 @@ public partial class Form1 : Form
     {
         public static Dictionary<string, string> unityList = new Dictionary<string, string>();
         const string contextRegRoot = "Software\\Classes\\Directory\\Background\\shell";
-        bool isDownloadUnityList = false;
         const string launcherArgumentsFile = "LauncherArguments.txt";
+        const string githubReleaseCheckURL = "https://api.github.com/repos/unitycoder/unitylauncher/releases/latest";
+        const string githubReleasesURL = "https://github.com/unitycoder/UnityLauncher/releases";
+
+        bool isDownloadUnityList = false;
+        string previousGitRelease = null;
 
 
         public Form1()
@@ -91,6 +96,15 @@ void Start()
 
             // subscribe to columnwidthchange event, so that can save column sizes
             this.gridRecent.ColumnWidthChanged += new System.Windows.Forms.DataGridViewColumnEventHandler(this.gridRecent_ColumnWidthChanged);
+
+
+            // get previous version build info string
+            // this string is release tag for latest release when this app was compiled
+            using (Stream stream = Assembly.GetExecutingAssembly().GetManifestResourceStream("UnityLauncher." + "PreviousVersion.txt"))
+            using (StreamReader reader = new StreamReader(stream))
+            {
+                previousGitRelease = reader.ReadToEnd().Trim();
+            }
         }
 
         void LoadSettings()
@@ -952,6 +966,11 @@ private void gridRecent_CellEndEdit(object sender, DataGridViewCellEventArgs e)
             //            gridRecent.Rows[previousRow].Selected = true;
         }
 
+        private void btnCheckUpdates_Click(object sender, EventArgs e)
+        {
+            CheckUpdates();
+        }
+
         #endregion UI events
 
         // displays version selector to upgrade project
@@ -1068,5 +1087,23 @@ string GetSelectedRowData(string key)
             }
             return path;
         }
+
+        void CheckUpdates()
+        {
+            var result = Tools.CheckUpdates(githubReleaseCheckURL, previousGitRelease);
+            if (string.IsNullOrEmpty(result) == false)
+            {
+                SetStatus("Update available: " + result);
+                DialogResult dialogResult = MessageBox.Show("Update " + result + " is available, open download page?", "UnityLauncher - Check Update", MessageBoxButtons.YesNo);
+                if (dialogResult == DialogResult.Yes) // open download page
+                {
+                    Tools.OpenURL(githubReleasesURL);
+                }
+            }
+            else
+            {
+                SetStatus("No updates available..");
+            }
+        }
     }
-}
+}

Diff for: UnityLauncher/Form1.cs

@@ -4,6 +4,7 @@
 using System.Diagnostics;
 using System.IO;
 using System.Linq;
+using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
 using System.Threading.Tasks;
@@ -324,5 +325,39 @@ public static bool LaunchExplorer(string folder)
             return result;
         }
 
+        public static string CheckUpdates(string githubReleaseURL, string previousGitRelease)
+        {
+            string result = null;
+            using (WebClient client = new WebClient())
+            {
+                client.Headers.Add("user-agent", "MuskBrowser");
+                string json = client.DownloadString(githubReleaseURL);
+                var arr = json.Split(new string[] { "\"tag_name\":" }, StringSplitOptions.None);
+
+                // have tagname
+                if (arr.Length > 1)
+                {
+                    var arr2 = arr[1].Trim().Split('"');
+                    // have "
+                    if (arr2.Length > 1)
+                    {
+                        var currentlyAvailableLatestReleaseTag = arr2[1];
+                        // compare with this build release version
+                        if (currentlyAvailableLatestReleaseTag != previousGitRelease)
+                        {
+                            result = currentlyAvailableLatestReleaseTag;
+                            Console.WriteLine("update available: [" + currentlyAvailableLatestReleaseTag + "] / [" + previousGitRelease + "]");
+                        }
+                        else
+                        {
+                            Console.WriteLine("no update available: [" + currentlyAvailableLatestReleaseTag + "] / [" + previousGitRelease + "]");
+                        }
+                    }
+                }
+            }
+            return result;
+        }
+
+
     }
 }

Diff for: UnityLauncher/PreviousVersion.txt

@@ -127,7 +127,11 @@
     </BootstrapperPackage>
   </ItemGroup>
   <ItemGroup>
+    <EmbeddedResource Include="PreviousVersion.txt" />
     <Content Include="unitylauncher.ico" />
   </ItemGroup>
   <Import Project="$(MSBuildToolsPath)\Microsoft.CSharp.targets" />
+  <PropertyGroup>
+    <PreBuildEvent>powershell.exe -command "$web = New-Object System.Net.WebClient;$web.Headers['User-Agent'] = 'DefinitelyBrowser';$results = $web.DownloadString('https://api.github.com/repos/unitycoder/unitylauncher/releases/latest');$results = $results | ConvertFrom-Json;$results = $results | select -expand tag_name;echo $results | Out-File $(ProjectDir)PreviousVersion.txt;"</PreBuildEvent>
+  </PropertyGroup>
 </Project>