refactor<*>: rewrite all codes...

src/Commands/Checkout.cs

@@ -0,0 +1,46 @@
+using System.Collections.Generic;
+using System.Text;
+
+namespace SourceGit.Commands {
+    /// <summary>
+    ///     检出
+    /// </summary>
+    public class Checkout : Command {
+
+        public Checkout(string repo) {
+            Cwd = repo;
+        }
+
+        public bool Branch(string branch) {
+            Args = $"checkout {branch}";
+            return Exec();
+        }
+
+        public bool Branch(string branch, string basedOn) {
+            Args = $"checkout -b {branch} {basedOn}";
+            return Exec();
+        }
+
+        public bool File(string file, bool useTheirs) {
+            if (useTheirs) {
+                Args = $"checkout --theirs -- \"{file}\"";
+            } else {
+                Args = $"checkout --ours -- \"{file}\"";
+            }
+
+            return Exec();
+        }
+
+        public bool Files(List<string> files) {
+            StringBuilder builder = new StringBuilder();
+            builder.Append("checkout -qf --");
+            foreach (var f in files) {
+                builder.Append(" \"");
+                builder.Append(f);
+                builder.Append("\"");
+            }
+            Args = builder.ToString();
+            return Exec();
+        }
+    }
+}