Author: h.mohri
I tried a program that reads a JSON file in C++Builder VCL and displays it in TTreeView component.
This project file is open to public from github.
https://www.microsoft.com/store/productid/9PLPHK05PJF7
Place two TSpeedButton, TTreeView, TMemo, TActivityIndicator, TOpenDialog, TImageList.
ImageList1 has an icon for displaying in TreeView1
[code]
Create an event to read a JSON file and an event to read a character string contained in the clipboard.
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//--------------------------------------------------------------------------- void __fastcall TForm1::SpeedButton1Click(TObject *Sender) { //Read JSON file. if (OpenDialog1-＞Execute(this-＞Handle) ) { if (FileExists(OpenDialog1-＞FileName) ) { UnicodeString s_ = file_towstring(OpenDialog1-＞FileName); if (s_.Length() ＞ 0) { start_js_build(s_); } } } } void __fastcall TForm1::SpeedButton2Click(TObject *Sender) { //Read the character string contained in the clipboard. start_js_build(Clipboard()-＞AsText); } |
[Read JSON and add it to TreeView 1-＞Items]
Code to add from JSON string to ”TreeView 1->Items” using TJsonTextReader.
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//--------------------------------------------------------------------------- void __fastcall TForm1::addChild_(TJsonTextReader* jsr, std::stack＜TTreeNode* ＞& st_, UnicodeString value_, const int imagenum) { UnicodeString path_ = StringReplace(jsr-＞Path, st_.top()-＞Text, "", TReplaceFlags() ＜＜ System::Sysutils::rfReplaceAll); if (Pos(".", path_) == 1) path_.Delete(1, 1); TThread::Synchronize(TThread::CurrentThread, [this, &st_, jsr, &path_, &value_, &imagenum](){ TTreeNode* node_ = TreeView1-＞Items-＞AddChild(st_.top(),path_ + ":" + value_); Memo1-＞Lines-＞Append(path_ + " = " + value_); node_-＞ImageIndex = imagenum; node_-＞SelectedIndex = imagenum; }); } void __fastcall TForm1::json_totree_(TJsonTextReader* jsr) { TThread::CreateAnonymousThread([this, jsr](){ std::stack＜TTreeNode* ＞ st_; try { while (jsr-＞Read() ) { switch (jsr-＞TokenType) { case TJsonToken::StartObject: TThread::Synchronize(TThread::CurrentThread, [this, &st_, jsr](){ (st_.empty())? st_.push(TreeView1-＞Items-＞Add(nullptr, "JSON")): st_.push(TreeView1-＞Items-＞AddChild(st_.top(), jsr-＞Path)); if (st_.top() != nullptr) { st_.top()-＞ImageIndex = 0; st_.top()-＞SelectedIndex = 0; if (jsr-＞Path.Length() ＞ 0) { Memo1-＞Lines-＞Append("[" + jsr-＞Path + "]"); } } }); break; case TJsonToken::StartArray: case TJsonToken::PropertyName: break; case TJsonToken::String: addChild_(jsr, st_, jsr-＞Value.AsString() + " (string)",1 ); break; case TJsonToken::Integer: addChild_(jsr, st_, IntToStr(jsr-＞Value.AsInteger()) + " (integer)" , 2); break; case TJsonToken::Float: addChild_(jsr, st_, CurrToStr(jsr-＞Value.AsCurrency()) + " (float)" ,2); break; case TJsonToken::Boolean: addChild_(jsr, st_, BoolToStr(jsr-＞Value.AsBoolean()) + " (bool)" ,2); break; case TJsonToken::Null: addChild_(jsr, st_, "null" ,3); break; case TJsonToken::EndArray: break; case TJsonToken::EndObject: st_.pop(); break; } } } __finally { TThread::Synchronize(TThread::CurrentThread, [this](){ SpeedButton1-＞Enabled = true; SpeedButton2-＞Enabled = true; Panel4-＞Visible = false; }); } })-＞Start(); } |
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