Visual Studio中的錯誤：無法將類型'字符串'隱式轉換爲'int'

Question

這是家庭作業，它是Visual Studio中使用C＃的ASP.NET MVC應用程序。當我運行它時，錯誤說：「不能隱式地將類型'字符串'轉換爲'int'，」參考下面這行：Manufacturer = collection [「Manufacturer」]，Gears = collection [「Gears」]，Frame = collection [ 「Frame」]，Gears = collection [「Gears」]下面有一條波浪線。

using MvcApplication3.Models; 
using System; 
using System.Collections.Generic; 
using System.Linq; 
using System.Web; 
using System.Web.Mvc; 

namespace MvcApplication3.Controllers 
{ 
    public class BikeController : Controller 
    { 
     // 
     // GET: /Bike/ 

     List<Bike> bikes; 


     public BikeController() 
     { 
      if (bikes == null) 
      { 
       bikes = new List<Bike> { 
       new Bike(), 
       new Bike { Manufacturer = "Nishiki", Gears = 5, Frame = "Road" } 
      }; 
      } 
     } 

     public ActionResult Index() 
     { 
      return View(this.bikes); 
     } 

     private ActionResult View(Func<object> func) 
     { 
      throw new NotImplementedException(); 
     } 

     // 
     // GET: /Bike/Details/5 

     public ActionResult Details(int id) 
     { 
      var currentBikes = bikes[id]; 
      return View(currentBikes); 

     } 

     // 
     // GET: /Bike/Create 

     public ActionResult Create() 
     { 
      return View(); 
     } 

     // 
     // POST: /Bike/Create 

     [HttpPost] 
     public ActionResult Create(FormCollection collection) 
     { 
      Bike b = new Bike 
      { 
       Manufacturer = collection["Manufacturer"], Gears = collection["Gears"], Frame = collection["Frame"] 
      }; 
      bikes.Add(b); 
      try 
      { 
       return RedirectToAction("Index"); 
      } 
      catch 
      { 
       return View(); 
      } 
     } 

     // 
     // GET: /Bike/Edit/5 

     public ActionResult Edit(int id) 
     { 
      return View(bikes.Where(b => b.BikeID == id).First()); 
     } 

     // 
     // POST: /Bike/Edit/5 

     [HttpPost] 
     public ActionResult Edit(int id, FormCollection collection) 
     { 
      try 
      { 
       // TODO: Add update logic here 

       return RedirectToAction("Index"); 
      } 
      catch 
      { 
       return View(); 
      } 
     } 

     // 
     // GET: /Bike/Delete/5 

     public ActionResult Delete(int id) 
     { 
      return View(); 
     } 

     // 
     // POST: /Bike/Delete/5 

     [HttpPost] 
     public ActionResult Delete(int id, FormCollection collection) 
     { 
      try 
      { 
       // TODO: Add delete logic here 

       return RedirectToAction("Index"); 
      } 
      catch 
      { 
       return View(); 
      } 
     } 

     public int bike { get; set; } 
    } 
} 

Answer 1

您需要將字符串顯式轉換爲int。

嘗試以下行

Manufacturer = collection["Manufacturer"], Gears = int.Parse(collection["Gears"]), Frame = collection["Frame"]