這幾天在玩個程式,突然看到c#採用圖toml檔案,好用,直觀,確實也簡單。
不過。。。。。。
github上示例寫的
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,於是改了個float型別的引數測試測試,魔咒來了。
Console.WriteLine("ServerAddress: " + toml.Get<TomlTable>("Client").Get<float>("floatXXX"));
讀取一切正常,
下一步呢?修改修改?於是看來看去有個Update函式
toml.Get<TomlTable>("Server").Update("
floatXXX
",(double)fV);
噩夢,於是1.1存進去變成了值 1.00999999046326,怎麼測試都不對,這是什麼鬼
百度https://www.baidu.com/s?ie=UTF-8&tn=62095104_35_oem_dg&wd=1.00999999046326也有這個莫名其妙的數字
百思不得其解,然後下載了https://github.com/paiden/Nett原始碼看看:
// 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));
琢磨出點門道來了,沒有float型別啊,於是改為double,一切風平浪靜,回歸正常。
OMG,這個。。。。
得出個結論,c#用toml檔案讀取非整數字請用double,不要用float,decimal倒無所謂,反正編譯不過,切記不要用float。
特此記錄,避免打擊迷茫,也算一個玩程式中的不太有用知識點,算是記錄吧。
20240420