代码分析 AvoidExcessiveComplexity - 只需设置命令

Question

我有一个 WPF 表单，上面有 16 个按钮。当我的视图模型初始化时，我需要将所有 16 个设置为 RelayCommand 对象。这就是我的 Initialize() 方法所做的全部，但这会导致代码分析错误 CA1502:AvoidExcessiveComplexity。

这是抑制 CA 警告的好案例，还是有更优雅的方法来设置这些命令而不会导致 CA 违规？

[SuppressMessage("Microsoft.Maintainability", "CA1502:AvoidExcessiveComplexity", Justification = "Simply setting the commands")]
private void Initialize()
{
    this.AddApplicationCommand      = new RelayCommand(_ => AddApplication());
    this.DeleteApplicationCommand   = new RelayCommand(_ => DeleteApplication(), _ => ApplicationIsSelected);
    this.RefreshApplicationsCommand = new RelayCommand(_ => RefreshApplications());
    this.SaveApplicationCommand     = new RelayCommand(_ => SaveApplication(), _ => ApplicationIsSelected);

    this.ForceInstallationCommand       = new RelayCommand(_ => ForceInstallation(), _ => ApplicationIsSelected);
    this.DeleteForceInstallationCommand = new RelayCommand(_ => DeleteForceInstallation(), _ => ApplicationIsSelectedAndForceExists());

    this.AddTaskCommand            = new RelayCommand(_ => AddTask(), _ => ApplicationIsSelected);
    this.EditTaskCommand           = new RelayCommand(_ => EditTask(), _ => TaskIsSelected());
    this.DeleteTaskCommand         = new RelayCommand(_ => DeleteTask(), _ => TaskIsSelected());
    this.ImportTasksCommand        = new RelayCommand(_ => ImportTasks(), _ => ApplicationIsSelected);
    this.ExportTasksCommand        = new RelayCommand(_ => ExportTasks(), _ => TaskIsSelected());
    this.ImportLegacyTasksCommand  = new RelayCommand(_ => ImportLegacyTasks(), _ => ApplicationIsSelected);            
    this.MoveTaskUpCommand         = new RelayCommand(_ => MoveRowUp(), _ => TaskIsSelected());
    this.MoveTaskDownCommand       = new RelayCommand(_ => MoveRowDown(), _ => TaskIsSelected());

    this.AddVariableGroupCommand    = new RelayCommand(_ => AddVariableGroup());
    this.RemoveVariableGroupCommand = new RelayCommand(_ => RemoveVariableGroup(), _ => VariableGroupIsSelected());
}

Answer 1

由于使用了匿名方法，这是误报。该规则不会将编译器生成的分支识别为生成的代码。有关现有错误报告，请参阅 https://connect.microsoft.com/VisualStudio/feedback/details/555560/method-using-many-lambda-expressions-causes-high-cyclomatic-complexity 和 https://connect.microsoft.com/VisualStudio/feedback/details/295703/incorrect-cyclomatic-complexity-with-lambdas。

Answer 2

看起来可读，所以对我来说抑制是可以的（假设你不能更改 RelayCommand）。

如果您可以控制 RelayCommand 类 - 添加构造函数 RealayCommand(Action, Func<bool>) 以消除额外的包装 lambda/委托创建。

如果您希望有更多按钮，请考虑切换到带有 { button, action, enabled } 条目的表格。

编辑：要通过删除每一行上的委托创建来简化代码，您可以更改代码

new RelayCommand(_ => MoveRowDown(), _ => TaskIsSelected());

到

new RelayCommand(MoveRowDown, TaskIsSelected);

通过添加设置文件本身的新构造函数：

public RelayCommand(Action action, Func<bool> enabled)
{
  this._execute = _ => action();
  this._enabled = _ => enabled();
}

或调用现有构造函数的新构造函数：

public RelayCommand(Action action, Func<bool> enabled)
 : this(_ => MoveRowDown(), _ => TaskIsSelected()) {}