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System.Exception：表没有（公共）列(System.Exception: Table has no (public) columns)

 我正在使用Xamarin.Android在visual studio 2015上开发Android，我在PCL项目上遇到以下错误：  
Unhandled Exception:
10-04 01:47:04.594 E/mono    ( 3322): System.Exception: Table has no (public) columns
10-04 01:47:04.594 E/mono    ( 3322):   at SQLite.Net.SQLiteConnection.CreateTable (System.Type ty, CreateFlags createFlags) [0x0002e] in <filename unknown>:0 
10-04 01:47:04.594 E/mono    ( 3322):   at SQLite.Net.Async.SQLiteAsyncConnection+<>c__DisplayClass11_0.<CreateTablesAsync>b__0 () [0x0002b] in <filename unknown>:0 
 
 我的打包属性是关闭Use Shared Runtime 。  
 我的链接器属性设置为链接Sdk and User Assemblies集。  
 我支持arm和x86架构，我的Java Mas Heap Size是1G 。  
 我已经搜索过这个错误，但我找不到任何相关的东西。  
 当SQLite尝试为此实体创建表时发生错误：  
[Table("User")]
public class User : IBusinessEntity
{
    [PrimaryKey, AutoIncrement]
    public long Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
    public string Password { get; set; }
    public DateTime CreationDate { get; set; }
}
 
 我正在使用SQLite.Net.Async-PCL库。 

I'm developing for Android on visual studio 2015 using Xamarin.Android and I'm getting the following error on the PCL project: 
Unhandled Exception:
10-04 01:47:04.594 E/mono    ( 3322): System.Exception: Table has no (public) columns
10-04 01:47:04.594 E/mono    ( 3322):   at SQLite.Net.SQLiteConnection.CreateTable (System.Type ty, CreateFlags createFlags) [0x0002e] in <filename unknown>:0 
10-04 01:47:04.594 E/mono    ( 3322):   at SQLite.Net.Async.SQLiteAsyncConnection+<>c__DisplayClass11_0.<CreateTablesAsync>b__0 () [0x0002b] in <filename unknown>:0 
 
My packaging properties are setting Use Shared Runtime off. 
My linker properties are set to link Sdk and User Assemblies. 
I'm supporting both arm and x86 architectures and my Java Mas Heap Size is 1G. 
I already search about this error, but I couldn't find anythig relevent. 
The error occurs when SQLite tries to create a table for this entity: 
[Table("User")]
public class User : IBusinessEntity
{
    [PrimaryKey, AutoIncrement]
    public long Id { get; set; }
    public string Name { get; set; }
    public string Email { get; set; }
    public string Password { get; set; }
    public DateTime CreationDate { get; set; }
}
 
I'm using SQLite.Net.Async-PCL library.

原文：https://stackoverflow.com/questions/39843074

更新时间：2023-08-23 10:08

最满意答案

 您甚至不需要遍历名称，为什么不使用Contains呢？  
 这里的技巧是使用Enum.Parse 。 在检查颜色有效后，只需调用Enum.Parse ：  
public void setColor(string col){
    if (Enum.GetNames(typeof(Color)).Contains(col)) {
        color = (Color)Enum.Parse(typeof(Color), col);
    }
}

You don't need to even loop through the names, why not just use Contains? 
The trick here is to use Enum.Parse. Just stick a call to Enum.Parse after you checked that the color is valid: 
public void setColor(string col){
    if (Enum.GetNames(typeof(Color)).Contains(col)) {
        color = (Color)Enum.Parse(typeof(Color), col);
    }
}

System.Exception：表没有（公共）列(System.Exception: Table has no (public) columns)

最满意答案

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