Razor Page表单绑定后无法获取用户提交内容该如何解决？

• 类属性的set访问器为private：ASP.NET Core模型绑定系统在接收表单提交数据时，需要对绑定目标的属性进行写入操作，private级别的set访问器会阻止写入，导致所有属性保留默认值（int为0、字符串为null、bool为false）
• 布尔类型字段绑定不匹配：表单中isEmergency下拉选项的值为Yes/No，无法自动转换为C#的bool类型，导致绑定失败
• 可选展示问题：Byline对应的label标签asp-for属性错误绑定到了title字段，仅影响展示不影响绑定逻辑
• 可选遗漏问题：如果PageModel中的ArticleNews属性未添加[BindProperty]特性，Razor Page默认不会对POST请求的页面属性进行自动绑定

1. 修改属性访问权限 #

将Article基类和NewsArticle子类中需要绑定的属性set访问器改为public：

public abstract class Article
{
    public Article()
    { }

    public Article(int id, string title, string text)
    {
        this.id = id;
        this.title = title;
        this.text = text;
    }

    [Required]
    public int id { get; set; }
   
    public string title { get; set; }
    
    public string text { get; set; }

    public bool HasID(int id)
    {
        return id == this.id;
    }

    public override string ToString()
    {
        return "Id: " + id + " Title: " + title + " Text: " + text;
    }
}

public class NewsArticle : Article
{
    public NewsArticle()
        {}

    public NewsArticle(int id, string title, string text, bool isEmergency, string byLine, string source)
        : base(id, title, text)
    {
        this.isEmergency = isEmergency;
        this.byLine = byLine;
        this.source = source;
    }

   
    public bool isEmergency { get; set; }
  
    public string byLine { get; set; }
    
    public string source { get; set; }

    public override string ToString()
    {
        return base.ToString() + " Made by: " + byLine + " Used sources: " + source;
    }
}

2. 修正布尔字段下拉选项 #

将isEmergency下拉框的value值改为和bool类型匹配的true/false：

<select asp-for="ArticleNews.isEmergency">
    <option value=""></option>
    <option value="true">Yes</option>
    <option value="false">No</option>
</select>

3. 修正错误的label绑定 #

修改Byline对应的label标签：

<label asp-for="ArticleNews.byLine">Byline*</label>

4. 为PageModel属性添加绑定特性 #

确认你的MakeNewsArticleModel中ArticleNews属性添加了[BindProperty]特性：

public class MakeNewsArticleModel : PageModel
{
    [BindProperty]
    public NewsArticle ArticleNews { get; set; }

    public IActionResult OnPost()
    {
        if (ModelState.IsValid)
        {
            // 替换为你的输出逻辑即可正常读取提交数据
            ViewData["Message"] = $"The article id is: {ArticleNews.id} The title is: {ArticleNews.title} It is written by: {ArticleNews.byLine} The written text is: {ArticleNews.text} It was an {ArticleNews.isEmergency} news article And the used source was: {ArticleNews.source}";
        }
        return Page();
    }
}

内容的提问来源于stack exchange，提问作者Jessy