我有一个相当简单的JSON:
[
{
"hero-img": "girl-ipad.png",
"main-story-headline": "How to Stay Mentally Healthy During a Pandemic",
"main-story-paragraph": "lorem ipsum",
"main-story-button-text": "Read More"
},
{
"hero-img": "painter-woman.png",
"main-story-headline": "How to Stay Mentally Healthy During a Pandemic",
"main-story-paragraph": "lorem ipsum",
"main-story-button-text": "Explore More"
},
{
"hero-img": "old-man.png",
"main-story-headline": "How to Stay Mentally Healthy During a Pandemic",
"main-story-paragraph": "lorem ipsum",
"main-story-button-text": "Get Yours Now"
} ]
通过使用Delphi 10.3 RIO,我想遍历所有属性,无论它们如何调用。我是这样开始的:
program JuTemplates;
{$APPTYPE CONSOLE}
{$R *.res}
uses
System.SysUtils, System.JSON, System.IOUtils, System.Types;
var
root, OutputDir, TemplatesDir, JsonDir, jsonText: string;
JsonFiles: TStringDynArray;
i, j: Integer;
JSONValue: TJSONObject;
JSONValues: TJSONArray;
begin
try
try
root := ExtractFilePath(ParamStr(0));
OutputDir := root + 'OutputDir\';
TemplatesDir := root + 'TemplatesDir\';
JsonDir := root + 'JsonDir\';
writeln('Processing: ' + JsonDir);
JsonFiles := TDirectory.GetFiles(JsonDir);
for i := 0 to High(JsonFiles) do
begin
jsonText := TFILE.ReadAllText(JsonFiles[i]);
JSONValues := TJSONObject.ParseJSONValue(jsonText) as TJSONArray;
for j := 0 to JSONValues.Count - 1 do
begin
JSONValue := JSONValues.Items[i] as TJSONObject;
// here I should iterate through that JSONValue object
end;
end;
except
on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
finally
writeln ('Press any key to continue');
readln;
end;
end.
要枚举JSONObject,可以使用如下枚举器。
用于for..in循环(隐式枚举器)
procedure TForm1.Button1Click(Sender: TObject);
var
JSONData : String;
JSONObject : TJSONObject;
JSONPair : TJSONPair;
begin
JSONData := '... some JSON data ...'; // Place you data here
JSONObject := TJSonObject.ParseJSONValue(JSONData) as TJSONObject;
try
for JSONPair in JSONObject do
ShowMessage(Format('1) Key=%s Value=%s',
[JSONPair.JsonString.ToString,
JSONPair.JsonValue.ToString]));
finally
JSONObject.Free;
end;
end;
使用经典的for循环:
procedure TForm1.Button1Click(Sender: TObject);
var
JSONData : String;
JSONObject : TJSONObject;
JSONPair : TJSONPair;
I : Integer;
begin
JSONData := '... some JSON data ...'; // Place you data here
JSONObject := TJSonObject.ParseJSONValue(JSONData) as TJSONObject;
try
for I := 0 to JSONObject.Count - 1 do begin
ShowMessage(Format('Key=%s Value=%s',
[JSONObject.Pairs[I].JsonString.ToString,
JSONObject.Pairs[I].JsonValue.ToString]));
end;
finally
JSONObject.Free;
end;
end;
使用一个显式的枚举器和一个while循环:
procedure TForm1.Button1Click(Sender: TObject);
var
JSONData : String;
JSONObject : TJSONObject;
JSONEnumerator : TJSONObject.TEnumerator;
JSONPair : TJSONPair;
begin
JSONData := '... some JSON data ...'; // Place you data here
JSONObject := TJSonObject.ParseJSONValue(JSONData) as TJSONObject;
try
JSONEnumerator := JSONObject.GetEnumerator;
try
while JSONEnumerator.MoveNext do begin
JSONPair := JSONEnumerator.Current;
ShowMessage(Format('Key=%s Value=%s',
[JSONPair.JsonString.ToString,
JSONPair.JsonValue.ToString]));
end;
finally
JSONEnumerator.Free;
end;
finally
JSONObject.Free;
end;
end;
请注意,您可能需要检查JSONPair.JsonValue是否具有子项,然后递归地用另一个枚举器枚举那些子项。
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我来说两句