C# How to read multiple json data in txt file

Question

Excuse me, I am a Rookie in C#.
I have a txt file like this

{"ID":1,"ScrewDiameter":28.0,"InjectionStroke":139.7,"InjectionVolume":86.0,"InjectionPressure":1857.0,"InjectionRate":62.0,"ClampForce":55.0,"MinMoldHeight":180.0,"MaxStroke":380.0,"InjectionSpeed":100.0,"CreateDate":null}
{"ID":2,"ScrewDiameter":36.0,"InjectionStroke":140.0,"InjectionVolume":143.0,"InjectionPressure":1842.0,"InjectionRate":90.0,"ClampForce":85.0,"MinMoldHeight":200.0,"MaxStroke":450.0,"InjectionSpeed":100.0,"CreateDate":null}

I want to get two data to show

but it shows

Newtonsoft.Json.JsonReaderException: Unexpected character encountered while parsing value: <. Path '', line 0, position 0.


於 Newtonsoft.Json.JsonTextReader.ParseValue()
於 Newtonsoft.Json.JsonTextReader.ReadInternal()
於 Newtonsoft.Json.JsonTextReader.Read()
於 Newtonsoft.Json.Serialization.JsonSerializerInternalReader.ReadForType(JsonReader reader, JsonContract contract, Boolean hasConverter)
於 Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
於 Newtonsoft.Json.Serialization.JsonSerializerInternalReader.Deserialize(JsonReader reader, Type objectType, Boolean checkAdditionalContent)
於 Newtonsoft.Json.JsonConvert.DeserializeObject(String value, Type type, JsonSerializerSettings settings)
於 Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value, JsonSerializerSettings settings)
於 Newtonsoft.Json.JsonConvert.DeserializeObject[T](String value)
於 WindowsFormsAppgetData.Form1.ReadFromJsonFile[machine2](String filePath) 
於 C:\Users\Shih-Hao.Su\source\repos\WindowsFormsAppgetData\WindowsFormsAppgetData\Form1.cs: 行 50

'[13104] WindowsFormsAppgetData.exe' 程式以返回碼 -1 (0xffffffff) 結束。

I use this example

json

How to save/restore serializable object to/from file?

and change append = true

I expected results like

"ID":1,"ScrewDiameter":28.0,"InjectionStroke":139.7,"InjectionVolume":86.0,"InjectionPressure":1857.0,"InjectionRate":62.0,"ClampForce":55.0,"MinMoldHeight":180.0,"MaxStroke":380.0,"InjectionSpeed":100.0,"CreateDate":null
"ID":2,"ScrewDiameter":36.0,"InjectionStroke":140.0,"InjectionVolume":143.0,"InjectionPressure":1842.0,"InjectionRate":90.0,"ClampForce":85.0,"MinMoldHeight":200.0,"MaxStroke":450.0,"InjectionSpeed":100.0,"CreateDate":null

This format, commonly known as "ndjson", "newline delimited json", isn't supported out of the box by json.net. You will ned to read the contents of that file, one "line" at a time, and deserialize the resulting string to one object at a time. — Lasse V. Karlsen, Apr 08 '19 at 08:21

score 0 · Answer 1 · answered Apr 08 '19 at 08:09

0

1) Create a file, I named it "json.json"

2) Put this array inside:

[{"ID":1,"ScrewDiameter":28.0,"InjectionStroke":139.7,"InjectionVolume":86.0,"InjectionPressure":1857.0,"InjectionRate":62.0,"ClampForce":55.0,"MinMoldHeight":180.0,"MaxStroke":380.0,"InjectionSpeed":100.0,"CreateDate":null},{"ID":2,"ScrewDiameter":36.0,"InjectionStroke":140.0,"InjectionVolume":143.0,"InjectionPressure":1842.0,"InjectionRate":90.0,"ClampForce":85.0,"MinMoldHeight":200.0,"MaxStroke":450.0,"InjectionSpeed":100.0,"CreateDate":null}]

3) Use this code:

List<dynamic> objs = JsonConvert.DeserializeObject<List<dynamic>>(File.ReadAllText("json.json"));

answered Apr 08 '19 at 08:09

Marco Salerno

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thank you.but it shows Newtonsoft.Json.JsonReaderException HResult=0x80131500 Message=Unexpected character encountered while parsing value: <. Path '', line 0, position 0. – xeroxion Apr 08 '19 at 09:06
1

If you follow my answer, it can't happen, if you get this error, it means you did it differently. – Marco Salerno Apr 08 '19 at 09:13
Check your input file here, it looks like whatever is being loaded starts with a '<', perhaps it is XML not JSON? – Kyle Apr 08 '19 at 09:25

C# How to read multiple json data in txt file

1 Answers1