add more error checking to update checker, use TLS12 (suddenly windows requires it), update powershell script to use TLS12 also,

Author: unitycoder

Diff for: UnityLauncher/Form1.Designer.cs

@@ -20,10 +20,10 @@ public partial class Form1 : Form
         const string contextRegRoot = "Software\\Classes\\Directory\\Background\\shell";
         const string launcherArgumentsFile = "LauncherArguments.txt";
         const string githubReleaseAPICheckURL = "https://api.github.com/repos/unitycoder/unitylauncher/releases/latest";
-        const string githubReleasesURL = "https://github.com/unitycoder/UnityLauncher/releases";
+        const string githubReleasesLinkURL = "https://github.com/unitycoder/UnityLauncher/releases";
 
         bool isDownloadUnityList = false;
-        string previousGitRelease = null;
+        string previousGitRelease = "0";
 
 
         public Form1()
@@ -107,7 +107,6 @@ 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"))
@@ -1113,7 +1112,7 @@ void CheckUpdates()
                 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);
+                    Tools.OpenURL(githubReleasesLinkURL);
                 }
             }
             else

Diff for: UnityLauncher/Form1.cs

@@ -7,7 +7,6 @@
 using System.Net;
 using System.Text;
 using System.Text.RegularExpressions;
-using System.Threading.Tasks;
 using System.Windows.Forms;
 
 namespace UnityLauncherTools
@@ -336,9 +335,19 @@ public static string CheckUpdates(string githubReleaseURL, string previousGitRel
             string result = null;
             using (WebClient client = new WebClient())
             {
+                // apparently this is now required..otherwise: "The request was aborted: Could not create SSL/TLS secure channel"
+                ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12;
+
                 // fetch current release info
                 client.Headers.Add("user-agent", "MuskBrowser");
                 string json = client.DownloadString(githubReleaseURL);
+
+                if (json.IndexOf('{') != 0)
+                {
+                    // invalid json
+                    return result;
+                }
+
                 var arr = json.Split(new string[] { "\"tag_name\":" }, StringSplitOptions.None);
 
                 // have tagname
@@ -349,9 +358,14 @@ public static string CheckUpdates(string githubReleaseURL, string previousGitRel
                     if (arr2.Length > 1)
                     {
                         var currentlyAvailableLatestReleaseTag = arr2[1];
+
                         // compare online version with build in release version, return github version if different from embedded version
-                        if (Math.Abs(float.Parse(currentlyAvailableLatestReleaseTag)-float.Parse(previousGitRelease))>0.1f)
-//                            if (currentlyAvailableLatestReleaseTag != previousGitRelease)
+                        float previous = 0;
+                        float current = 0;
+                        if (float.TryParse(previousGitRelease, out previous) == false) return result;
+                        if (float.TryParse(currentlyAvailableLatestReleaseTag, out current) == false) return result;
+
+                        if (Math.Abs(previous - current) > 0.1f)
                         {
                             result = currentlyAvailableLatestReleaseTag;
                             Console.WriteLine("update available: [" + currentlyAvailableLatestReleaseTag + "] / [" + previousGitRelease + "]");

Diff for: UnityLauncher/Tools.cs

@@ -132,6 +132,6 @@
   </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 $(ProjectDir)PreviousVersion.txt;"</PreBuildEvent>
+    <PreBuildEvent>powershell.exe -command "[Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12;$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>