解决Settings被占用无法读取的问题

DownKyi.Core/Settings/SettingsManager.cs

@@ -57,9 +57,11 @@ namespace DownKyi.Core.Settings
         {
             try
             {
-                StreamReader streamReader = File.OpenText(settingsName);
+                FileStream fileStream = new FileStream(settingsName, FileMode.Open, FileAccess.Read, FileShare.ReadWrite);
+                StreamReader streamReader = new StreamReader(fileStream, System.Text.Encoding.UTF8);
                 string jsonWordTemplate = streamReader.ReadToEnd();
                 streamReader.Close();
+                fileStream.Close();
 
 #if DEBUG
 #else

DownKyi/ViewModels/Settings/ViewDanmakuViewModel.cs

@@ -144,7 +144,7 @@ namespace DownKyi.ViewModels.Settings
 
             // 弹幕字体
             string danmakuFont = SettingsManager.GetInstance().GetDanmakuFontName();
-            if (Fonts.Contains(danmakuFont))
+            if (danmakuFont != null && Fonts.Contains(danmakuFont))
             {
                 // 只有系统中存在当前设置的字体，才能显示
                 SelectedFont = danmakuFont;