WPF-22 基于MVVM员工管理-02

我们接着上一节，这节我们实现crud操作，我们在EmployeeViewMode类中新增如下成员，并在构造函数中初始化该成员

code snippet.

public EmployeeViewMode(){    employeeService = new EmployeeService();    BindData();    Employee = new Employee();    AddCommand = new DelegateCommand(Add);    GetEmployeeCommand = new DelegateCommand(GetEmployee);    UpdateCommand = new DelegateCommand(Update);    DeleteCommand = new DelegateCommand(Delete);}

WPF-22 基于MVVM员工管理-02

code snippet

private ICommand addCommand;public ICommand AddCommand{     get { return addCommand; }     set { addCommand = value; }}private ICommand getEmployeeCommand;public ICommand GetEmployeeCommand{     get { return getEmployeeCommand; }     set { getEmployeeCommand = value; }}private ICommand updateCommand;public ICommand UpdateCommand{     get { return updateCommand; }     set { updateCommand = value; }}private ICommand deleteCommand;public ICommand DeleteCommand{     get { return deleteCommand; }     set { deleteCommand = value; }}

定义每个Command委托执行的方法，code snippet

public void Add(){ try   {        var emp = new Employee()        {           No = Employee.No,           Name = Employee.Name,           Role = Employee.Role,         };         bool isAdded = employeeService.Add(emp);         if (isAdded)         {               BindData();               Message = "添加成功";          }          else               Message = "添加失败";  }   catch (Exception ex)    {          Message = ex.Message;    }}public void GetEmployee(){   try   {       var employee = employeeService.GetEmployee(Employee.No);       if (employee != null)       {                    var emp = new Employee()                    {                        No = employee.No,                        Name = employee.Name,                        Role = employee.Role,                    };                    this.Employee = emp;                }                else                    Message = "未发现当前用户";            }            catch (Exception ex)            {                Message = ex.Message;            }        }        public void Update()        {            try            {                var emp = new Employee()                {                    No = Employee.No,                    Name = Employee.Name,                    Role = Employee.Role                };                bool isUpdated = employeeService.Update(emp);                if (isUpdated)                {                    BindData();                    Message = "修改成功";                }                else                    Message = "修改失败";            }            catch (Exception ex)            {                Message = ex.Message;            }        }        private void Delete()        {            try            {                bool isDeleted = employeeService.Delete(Employee.No);                Employee.No = String.Empty;                Employee.Name = String.Empty;                Employee.Role = String.Empty;                if (isDeleted)                {                    BindData();                    Message = "修改成功";                }                else                    Message = "修改失败";            }            catch (Exception ex)            {                Message = ex.Message;            }        }

在EmployeeService 中添加如下方法：

        public bool Add(Employee employee)        {            _employees.Add(employee);            return true;        }        public bool Update(Employee employee)        {            bool isUpdated = false;            foreach (var item in _employees)            {                if (item.No == employee.No)                {                    item.Name = employee.Name;                    item.Role = employee.Role;                    isUpdated = true;                    break;                }            }            return isUpdated;        }        public bool Delete(string no)        {            bool isDeleted = false;            for (int i = 0; i < _employees.Count; i++)            {                if (_employees[i].No == no)                {                    _employees.RemoveAt(i);                    isDeleted = true;                }            }            return isDeleted;        }        public Employee? GetEmployee(string no)            => _employees.FirstOrDefault(x => x.No == no);

接下来我们将ViewModel中的Command和EmployeeView.xaml UI做绑定

WPF-22 基于MVVM员工管理-02

code snippet

<Button Content="新增" Width="100" Height="30" Margin="2" Command="{Binding Path=AddCommand}"></Button><Button Content="修改" Width="100" Height="30" Margin="2" Command="{Binding Path=UpdateCommand}"></Button><Button Content="删除" Width="100" Height="30" Margin="2" Command="{Binding Path=DeleteCommand}"></Button><Button Content="查询" Width="100" Height="30" Margin="2" Command="{Binding Path=GetEmployeeCommand}"></Button>

到这里我们基本完成对一个页面的增删改查

WPF-22 基于MVVM员工管理-02

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