c#采用toml做配置文件的坑过

这几天在玩个程序，突然看到c#采用图toml文件，好用，直观，确实也简单。

不过。。。。。。

github上示例写的

TOML to TomlTable

TOML input file:v

EnableDebug = true

[Server]
Timeout = 1m  [Client] ServerAddress = "http://127.0.0.1:8080" 

Code:

var toml = Toml.ReadFile(filename);
Console.WriteLine("EnableDebug: " + toml.Get<bool>("EnableDebug"));
Console.WriteLine("Timeout: " + toml.Get<TomlTable>("Server").Get<TimeSpan>("Timeout")); Console.WriteLine("ServerAddress: " + toml.Get<TomlTable>("Client").Get<string>("ServerAddress")); 

Output:

EnableDebug: True
Timeout: 00:01:00 ServerAddress: http://127.0.0.1:8080 

TomlTable is Nett's generic representation of a TomlDocument. It is a hash set based data structure where each key is represented as a string and each value as a TomlObject.

Using the TomlTable representation has the benefit of having TOML metadata - e.g. the Comments - available in the data model.

很好用，于是改了个float类型的参数测试测试，魔咒来了。

Console.WriteLine("ServerAddress: " + toml.Get<TomlTable>("Client").Get<float>("floatXXX"));


             读取一切正常，

             下一步呢？修改修改？于是看来看去有个Update函数

             toml.Get<TomlTable>("Server").Update("floatXXX",(double)fV);

             噩梦，于是1.1存进去变成了值 1.00999999046326，怎么测试都不对，这是什么鬼

             百度https://www.baidu.com/s?ie=UTF-8&tn=62095104_35_oem_dg&wd=1.00999999046326也有这个莫名其妙的数字


             百思不得其解，然后下载了https://github.com/paiden/Nett源码看看：

// Values

public static Result<TomlBool> Update(this TomlTable table, string key, bool value)

=> Update(table, key, table.CreateAttached(value));

public static Result<TomlString> Update(this TomlTable table, string key, string value)

=> Update(table, key, table.CreateAttached(value));

public static Result<TomlInt> Update(this TomlTable table, string key, long value)

=> Update(table, key, table.CreateAttached(value));

public static Result<TomlFloat> Update(this TomlTable table, string key, double value)

=> Update(table, key, table.CreateAttached(value));

public static Result<TomlOffsetDateTime> Update(this TomlTable table, string key, DateTimeOffset value)

=> Update(table, key, table.CreateAttached(value));

public static Result<TomlDuration> Update(this TomlTable table, string key, TimeSpan value)

=> Update(table, key, table.CreateAttached(value));

琢磨出点门道来了，没有float类型啊，于是改为double，一切风平浪静，回归正常。

OMG，这个。。。。

得出个结论，c#用toml文件读取非整数字请用double，不要用float，decimal倒无所谓，反正编译不过，切记不要用float。

特此记录，避免打击迷茫，也算一个玩程序中的不太有用知识点，算是记录吧。

20240420