refactor<*>: rewrite all codes...

src/Commands/QueryLFSObjectChange.cs

@@ -0,0 +1,41 @@
+namespace SourceGit.Commands {
+    /// <summary>
+    ///     查询LFS对象变更
+    /// </summary>
+    public class QueryLFSObjectChange : Command {
+        private Models.LFSChange change = new Models.LFSChange();
+
+        public QueryLFSObjectChange(string repo, string args) {
+            Cwd = repo;
+            Args = $"diff --ignore-cr-at-eol {args}";
+        }
+
+        public Models.LFSChange Result() {
+            Exec();
+            return change;
+        }
+
+        public override void OnReadline(string line) {
+            var ch = line[0];
+            if (ch == '-') {
+                if (change.Old == null) change.Old = new Models.LFSObject();
+                line = line.Substring(1);
+                if (line.StartsWith("oid sha256:")) {
+                    change.Old.OID = line.Substring(11);
+                } else if (line.StartsWith("size ")) {
+                    change.Old.Size = int.Parse(line.Substring(5));
+                }
+            } else if (ch == '+') {
+                if (change.New == null) change.New = new Models.LFSObject();
+                line = line.Substring(1);
+                if (line.StartsWith("oid sha256:")) {
+                    change.New.OID = line.Substring(11);
+                } else if (line.StartsWith("size ")) {
+                    change.New.Size = int.Parse(line.Substring(5));
+                }
+            } else if (line.StartsWith(" size ")) {
+                change.New.Size = change.Old.Size = int.Parse(line.Substring(6));
+            }
+        }
+    }
+}