- 合并 FreeSql.DbContext 项目至 FreeSql 维护；

FreeSql.DbContext/UnitOfWork/UnitOfWork.cs

@@ -0,0 +1,103 @@
+using SafeObjectPool;
+using System;
+using System.Data;
+using System.Data.Common;
+
+namespace FreeSql {
+	class UnitOfWork : IUnitOfWork {
+
+		protected IFreeSql _fsql;
+		protected Object<DbConnection> _conn;
+		protected DbTransaction _tran;
+
+		public UnitOfWork(IFreeSql fsql) {
+			_fsql = fsql;
+		}
+
+		void ReturnObject() {
+			_fsql.Ado.MasterPool.Return(_conn);
+			_tran = null;
+			_conn = null;
+		}
+
+
+        /// <summary>
+        /// 是否启用工作单元
+        /// </summary>
+        public bool Enable { get; private set; } = true;
+
+        /// <summary>
+        /// 禁用工作单元
+        /// <exception cref="Exception"></exception>
+        /// <para></para>
+        /// 若已开启事务（已有Insert/Update/Delete操作），调用此方法将发生异常，建议在执行逻辑前调用
+        /// </summary>
+        public void Close()
+        {
+            if (_tran != null)
+            {
+                throw new Exception("已开启事务，不能禁用工作单元");
+            }
+
+            Enable = false;
+        }
+
+        public void Open()
+        {
+            Enable = true;
+        }
+
+        public IsolationLevel? IsolationLevel { get; set; }
+
+		public DbTransaction GetOrBeginTransaction(bool isCreate = true) {
+
+			if (_tran != null) return _tran;
+			if (isCreate == false) return null;
+            if (!Enable) return null;
+			if (_conn != null) _fsql.Ado.MasterPool.Return(_conn);
+
+			_conn = _fsql.Ado.MasterPool.Get();
+			try {
+				_tran = IsolationLevel == null ? 
+					_conn.Value.BeginTransaction() : 
+					_conn.Value.BeginTransaction(IsolationLevel.Value);
+			} catch {
+				ReturnObject();
+				throw;
+			}
+			return _tran;
+		}
+
+		public void Commit() {
+			if (_tran != null) {
+				try {
+					_tran.Commit();
+				} finally {
+					ReturnObject();
+				}
+			}
+		}
+		public void Rollback() {
+			if (_tran != null) {
+				try {
+					_tran.Rollback();
+				} finally {
+					ReturnObject();
+				}
+			}
+		}
+		~UnitOfWork() {
+			this.Dispose();
+		}
+		bool _isdisposed = false;
+		public void Dispose() {
+			if (_isdisposed) return;
+			try {
+				this.Rollback();
+			} finally {
+				_isdisposed = true;
+				GC.SuppressFinalize(this);
+			}
+		}
+	}
+}