项目中遇到的一些需要重构的问题以及解决方案1应该尽量减少缩进层次

简单的判断对任何人来说都不难理解，而且加入条件判断非常容易，这往往导致大家无节制的使用深层次的条件判断，但如果层次过多，嵌套过多代码会非常不容易理解，这里结合项目中的几段代码来说说如何去除不必要的条件嵌套。

1、尽量去除else

修改前：

 public object GetEntityById(int? id, NameValueCollection nameValues)
        {
            object entity;
            if (id != null)
            {
                entity = EntityBll.GetEntityById(id.Value);
            }
            else
            {
                entity = EntityBll.GetNewEntity();

                if (nameValues != null)
                {
                    foreach (var n in nameValues.AllKeys)
                    {
                        EntityBll.SetEntityPropertyValue(entity, n, nameValues[n]);
                    };
                }
            }
            return entity;
        }

修改后：

public object GetEntityById(int? id, NameValueCollection nameValues)
        {
            
            if (id != null)
            {
                return EntityBll.GetEntityById(id.Value);
            }
            object entity= EntityBll.GetNewEntity();

            if (nameValues != null)
            {
                foreach (var n in nameValues.AllKeys)
                {
                    EntityBll.SetEntityPropertyValue(entity, n, nameValues[n]);
                };
            }

            return entity;
        }

 2、适当调整条件顺序去除条件层次

修改前：

public string GetString(string key, string culture)
        {
            Check.Argument.IsNotEmpty(key, "key");
            Check.Argument.IsNotEmpty(culture, "culture");
            var condition = new Dictionary<string, string>();
            condition.Add(CoreConstDefine.CodeColumnCode, key);
            condition.Add("LanguageName", culture);
            var dbLocalize = localize.GetEnumerable(condition).FirstOrDefault();
            var displayName = string.Empty;
            if (dbLocalize == null)
            {
                if (GetCulture() == CoreConstDefine.LanguageCN)
                {
                    dbLocalize = localize.GetNew();
                    dbLocalize.Code = key;
                    dbLocalize.LanguageName = CoreConstDefine.LanguageCN;
                    dbLocalize.DisplayName = string.Empty;
                    localize.Save(dbLocalize);
                }
            }
            else
            {
                displayName = dbLocalize.DisplayName;
            }

            return GetCultureString(culture, key, displayName);
        }

 修改后：

 public string GetString(string key, string culture)
        {
            Check.Argument.IsNotEmpty(key, "key");
            Check.Argument.IsNotEmpty(culture, "culture");
            var condition = new Dictionary<string, string>();
            condition.Add(CoreConstDefine.CodeColumnCode, key);
            condition.Add("LanguageName", culture);
            var dbLocalize = localize.GetEnumerable(condition).FirstOrDefault();
            var displayName = string.Empty;
            if (dbLocalize != null)
            {
                displayName = dbLocalize.DisplayName;

            }
            else if (GetCulture() == CoreConstDefine.LanguageCN)
            {
                dbLocalize = localize.GetNew();
                dbLocalize.Code = key;
                dbLocalize.LanguageName = CoreConstDefine.LanguageCN;
                dbLocalize.DisplayName = string.Empty;
                localize.Save(dbLocalize);
            }
            return GetCultureString(culture, key, displayName);
        }

3、不要因为性能问题而使代码重复

修改前

 private void chkAll_Click(object sender, RoutedEventArgs e)
        {
            CheckBox chk = sender as CheckBox;
            bool check = chk.IsChecked.Value;
            if (check)
            {
                foreach (object obj in dgUserList.ItemsSource)
                {
                    chk = dgUserList.Columns[0].GetCellContent(obj).FindName("chkUser") as CheckBox;
                    if (chk != null)
                    {
                        chk.IsChecked = true;
                    }
                }
            }
            else
            {
                foreach (object obj in dgUserList.ItemsSource)
                {
                    chk = dgUserList.Columns[0].GetCellContent(obj).FindName("chkUser") as CheckBox;
                    if (chk != null)
                    {
                        chk.IsChecked = false;
                    }
                }
            }
        }

修改后：

 private void chkAll_Click(object sender, RoutedEventArgs e)
        {
            CheckBox chk = sender as CheckBox;
            bool check = chk.IsChecked.Value;
            foreach (object obj in dgUserList.ItemsSource)
            {
                chk = dgUserList.Columns[0].GetCellContent(obj) as CheckBox;
                if (chk != null)
                {
                    chk.IsChecked = check;
                }
            }
        }

4、及时return

修改前

private void btnLogin_Click(object sender, RoutedEventArgs e)
        {
            
            if (string.IsNullOrEmpty(txtUserName.Text.Trim()))
            {
                txtUserName.Focus();
            }
            else
            {
                if (string.IsNullOrEmpty(txtPwd.Password.Trim()))
                {
                    txtPwd.Focus();
                }
                else
                {
                    try
                    {
                        EndpointAddress address = new EndpointAddress(GlobalData.loginService);
                        PollingDuplexHttpBinding binding = new PollingDuplexHttpBinding();

                        proxy = new LoginServiceClient(binding, address);

                        //LoginService.User
                        proxy.LoginMessageReceived += new EventHandler<LoginMessageReceivedEventArgs>(proxy_LoginMessageReceived);
                        proxy.LoginAsync(EnterpriseId +txtUserName.Text, txtPwd.Password);
                    }
                    catch (Exception ex)
                    {
                        MessageBox.Show(ex.Message);
                    }
                }              
            }            
        }

修改后：

 private void btnLogin_Click(object sender, RoutedEventArgs e)
        {
            if (string.IsNullOrEmpty(txtUserName.Text.Trim()))
            {
                txtUserName.Focus();
                return;
            }

            if (string.IsNullOrEmpty(txtPwd.Password.Trim()))
            {
                txtPwd.Focus();
                return;
            }

            try
            {
                EndpointAddress address = new EndpointAddress(GlobalData.loginService);
                PollingDuplexHttpBinding binding = new PollingDuplexHttpBinding();

                proxy = new LoginServiceClient(binding, address);

                //LoginService.User
                proxy.LoginMessageReceived += new EventHandler<LoginMessageReceivedEventArgs>(proxy_LoginMessageReceived);
                proxy.LoginAsync(EnterpriseId +txtUserName.Text, txtPwd.Password);
            }
            catch (Exception ex)
            {
                MessageBox.Show(ex.Message);
            }                        
        }