MVVM Prism WPF -设置公共属性和SetProperty

本文关键字：属性 SetProperty 设置 Prism WPF MVVM | 更新日期: 2023-09-27 18:11:20

我是MVVM和Prism的新手。我有下面的ViewModel 

    using System.Collections.Generic;
using BasicMVVMQuickstart_Desktop.Model;
using Microsoft.Practices.Prism.Mvvm;
namespace BasicMVVMQuickstart_Desktop.ViewModels
{
    public class QuestionnaireViewModel : BindableBase
    {
        private Questionnaire questionnaire;
        public QuestionnaireViewModel()
        {
            this.Questionnaire = new Questionnaire();
            this.AllColors = new[] { "Red", "Blue", "Green" };
        }
        public Questionnaire Questionnaire
        {
            get { return this.questionnaire; }
            set { 
                SetProperty(ref this.questionnaire, value);

            }
        }
        public IEnumerable<string> AllColors { get; private set; }
    }
}

我正试图从另一个视图模型设置问卷，并使用另一个视图模型的设定值更新WPF UI。但不幸的是，它不起作用。下面是另一个视图模型的代码。我在"私有void OnSubmit(object obj)"中设置了属性，但是当我运行应用程序并按下提交时，UI没有得到更新。有人知道这个工作还需要添加什么吗?如果我设置this。questionnaireviewmodel。questionnaire。Age = 32;" inside "public MainWindowViewModel()"，然后UI在运行时更新，但与OnSubmit不工作。请帮助。

 using System.Diagnostics;
using System.Text;
using System.Windows.Input;
using BasicMVVMQuickstart_Desktop.Model;
using Microsoft.Practices.Prism.Commands;
using Microsoft.Practices.Prism.Mvvm;
namespace BasicMVVMQuickstart_Desktop.ViewModels
{
    public class MainWindowViewModel : BindableBase
    {
        public MainWindowViewModel()
        {
            this.SubmitCommand = new DelegateCommand<object>(this.OnSubmit);
            this.QuestionnaireViewModel = new QuestionnaireViewModel();
            this.ResetCommand = new DelegateCommand(this.OnReset);
        }
        public ICommand SubmitCommand { get; private set; }
        public ICommand ResetCommand { get; private set; }
        public QuestionnaireViewModel QuestionnaireViewModel { get; set; }
        private void OnSubmit(object obj)
        {
          Debug.WriteLine(this.BuildResultString());
          this.QuestionnaireViewModel.Questionnaire.Age = 32;
        }
        private void OnReset()
        {
            this.QuestionnaireViewModel.Questionnaire = new Questionnaire();
        }
        private string BuildResultString()
        {
            StringBuilder builder = new StringBuilder();
            builder.Append("Name: ");
            builder.Append(this.QuestionnaireViewModel.Questionnaire.Name);
            builder.Append("'nAge: ");
            builder.Append(this.QuestionnaireViewModel.Questionnaire.Age);
            builder.Append("'nQuestion 1: ");
            builder.Append(this.QuestionnaireViewModel.Questionnaire.Quest);
            builder.Append("'nQuestion 2: ");
            builder.Append(this.QuestionnaireViewModel.Questionnaire.FavoriteColor);
            return builder.ToString();
        }
    }
}

MVVM Prism WPF -设置公共属性和SetProperty

当您在代码中更改Age属性时:

this.QuestionnaireViewModel.Questionnaire.Age = 32;

你改变了Questionnaire的属性，但没有改变QuestionnaireViewModel的属性。因此，您需要从BindableBase继承您的Questionnaire类，并为Age属性创建类似的代码:

private int _age;
public int Age
    {
        get { return _age; }
        set { SetProperty(ref _age, value); }
    }
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