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qjson中把记录或类型或泛型数组转换为json字符串

2016-09-022016-09-09 • Delphi、QDAC、QJSON、教程 • 暂无评论 • 老衲 •浏览 504 次

我一直都在寻找各种业务功能的最简单写法，用减法的模式来开发软件。如果有比我的写法更简单的方法，请留言告知。

unit Unit4;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type
  TForm4 = class(TForm)
    btn1: TButton;
    Memo1: TMemo;
    lbl1: TLabel;
    btn2: TButton;
    procedure btn1Click(Sender: TObject);
    procedure btn2Click(Sender: TObject);
  private
    { Private declarations }
  public
    { Public declarations }
  end;

/// <summary>
/// 新手留意，一定要定义在implementation关键词的上方.
/// </summary>
type TRenLei = record
  name: string;
  age: Integer;
  sex: Boolean;
end;


var
  Form4: TForm4;

implementation

{$R *.dfm}

uses qjson;

procedure TForm4.btn1Click(Sender: TObject);
var
  ARenLei: TRenLei;
  MyQj: TQJson;
begin
  MyQj := TQJson.Create;
  try
    //这个例子比较好理解
    ARenLei.name := '奥巴马';
    ARenLei.age := 1;
    ARenLei.sex := True;

    MyQj.FromRecord<TRenLei>(ARenLei);
    Memo1.Lines.Clear;
    Memo1.Lines.Add(MyQj.AsJson);
  finally
    MyQj.Free;
  end;
end;

procedure TForm4.btn2Click(Sender: TObject);
var
  RenLeiArray: TArray<TRenLei>;
  MyQj: TQJson;
begin
  MyQj := TQJson.Create;
  try
    SetLength(RenLeiArray,2);
    with RenLeiArray[0] do
    begin
      name := '拜登';
      age := 1;
      sex := True;
    end;
    with RenLeiArray[1] do
    begin
      name := '希拉里';
      age := 2;
      sex := False;
    end;

    //这里不是很好理解了，我也不理解，这里用TArray<TRenLei>就可以把泛型数组转换为Json，谁知道原理的请下方留言。
    MyQj.FromRecord<TArray<TRenLei>>(RenLeiArray);
    Memo1.Lines.Clear;
    Memo1.Lines.Add(MyQj.AsJson);
  finally
    MyQj.Free;
  end;
end;

end.

unit Unit4;

interface

uses

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls;

type

TForm4 = class(TForm)

btn1: TButton;

Memo1: TMemo;

lbl1: TLabel;

btn2: TButton;

procedure btn1Click(Sender: TObject);

procedure btn2Click(Sender: TObject);

private

{ Private declarations }

public

{ Public declarations }

end;

/// <summary>

/// 新手留意，一定要定义在implementation关键词的上方.

/// </summary>

type TRenLei = record

name: string;

age: Integer;

sex: Boolean;

end;

var

Form4: TForm4;

implementation

{$R *.dfm}

uses qjson;

procedure TForm4.btn1Click(Sender: TObject);

var

ARenLei: TRenLei;

MyQj: TQJson;

begin

MyQj := TQJson.Create;

try

//这个例子比较好理解

ARenLei.name := '奥巴马';

ARenLei.age := 1;

ARenLei.sex := True;

MyQj.FromRecord<TRenLei>(ARenLei);

Memo1.Lines.Clear;

Memo1.Lines.Add(MyQj.AsJson);

finally

MyQj.Free;

end;

procedure TForm4.btn2Click(Sender: TObject);

var

RenLeiArray: TArray<TRenLei>;

MyQj: TQJson;

begin

MyQj := TQJson.Create;

try

SetLength(RenLeiArray,2);

with RenLeiArray[0] do

begin

name := '拜登';

age := 1;

sex := True;

end;

with RenLeiArray[1] do

begin

name := '希拉里';

age := 2;

sex := False;

end;

//这里不是很好理解了，我也不理解，这里用TArray<TRenLei>就可以把泛型数组转换为Json，谁知道原理的请下方留言。

MyQj.FromRecord<TArray<TRenLei>>(RenLeiArray);

Memo1.Lines.Clear;

Memo1.Lines.Add(MyQj.AsJson);

finally

MyQj.Free;

end;

end.

[FMX] 获取 iOS 设备的类型名称

2016-08-312016-10-10 • Delphi、iOS、教程 • 暂无评论 • swish •浏览 769 次

[更新] 2016.10.10 增加 iPad 和 iPod 的几款新型设备 2016.9.30 修改了 GetDeviceModel 函数，由 sysctl 改成使用 uname（Delphi 没有声明，需要声明下）增加对 iPhone 7 的设备型号列表好吧，我承认这个函数不是必需的，只是为了满足我无耻的偷窥欲

新版 THttpClient组件同步下载文件方法。

2016-08-292016-08-30 • Delphi、教程、杂谈 • 6 条评论 • 老衲 •浏览 1,218 次

我一直都在寻找各种业务功能的最简单写法，用减法的模式来开发软件。下面是我下载文件的写法，如果有更简单的方法，请留言告知。

unit Unit3;

interface

uses
  Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,
  Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, System.Net.HttpClient,
  Vcl.ComCtrls;

type
  TForm3 = class(TForm)
    btnStart: TButton;
    ProgressBar1: TProgressBar;
    edt1: TEdit;
    procedure btnStartClick(Sender: TObject);
    procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);
    procedure FormShow(Sender: TObject);
    procedure FormCreate(Sender: TObject);
  private
    { Private declarations }

    /// <summary>
    /// 下载的时候不允许关闭窗体
    /// </summary>
    FAllowFormClose: Boolean;

    /// <summary>
    /// 接收数据事件
    /// </summary>
    procedure ReceiveDataEvent(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);
  public
    { Public declarations }
  end;

var
  Form3: TForm3;

implementation

{$R *.dfm}

procedure TForm3.ReceiveDataEvent(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);
begin
  //加上这句界面不卡死.
  Application.ProcessMessages;
  ProgressBar1.Position := AReadCount;
end;

procedure TForm3.btnStartClick(Sender: TObject);
var
  MyHTTPClient: THTTPClient;
  MyHTTPResponse: IHTTPResponse;
  MyMemoryStream: TMemoryStream;
  downloadUrl: string;
begin
  MyHTTPClient := THTTPClient.Create;
  MyMemoryStream := TMemoryStream.Create;
  try
    btnStart.Enabled := False;
    FAllowFormClose := False;
    downloadUrl := Trim(edt1.Text);

    //获取文件的大小
    MyHTTPResponse := MyHTTPClient.Head(downloadUrl);
    ProgressBar1.Position := 0;
    ProgressBar1.Max := MyHTTPResponse.ContentLength;

    //开始下载,保存到本地
    MyHTTPClient.OnReceiveData := ReceiveDataEvent;
    MyHTTPResponse := MyHTTPClient.Get(downloadUrl, MyMemoryStream);
    if MyHTTPResponse.StatusCode = 200 then
    begin
      MyMemoryStream.SaveToFile('c:\aa.exe');
      ShowMessage('下载完成');
    end;
  finally
    MyHTTPClient.Free;
    MyMemoryStream.Free;
    //最终都允许关闭窗体
    btnStart.Enabled := True;
    FAllowFormClose := True;
  end;
end;

procedure TForm3.FormCloseQuery(Sender: TObject; var CanClose: Boolean);
begin
  CanClose := FAllowFormClose;
end;

procedure TForm3.FormCreate(Sender: TObject);
begin
  ReportMemoryLeaksOnShutdown := True;
end;

procedure TForm3.FormShow(Sender: TObject);
begin
  btnStart.Enabled := True;
  FAllowFormClose := True;
  ProgressBar1.Position := 0;
end;

end.

100

101

102

unit Unit3;

interface

uses

Winapi.Windows, Winapi.Messages, System.SysUtils, System.Variants, System.Classes, Vcl.Graphics,

Vcl.Controls, Vcl.Forms, Vcl.Dialogs, Vcl.StdCtrls, System.Net.HttpClient,

Vcl.ComCtrls;

type

TForm3 = class(TForm)

btnStart: TButton;

ProgressBar1: TProgressBar;

edt1: TEdit;

procedure btnStartClick(Sender: TObject);

procedure FormCloseQuery(Sender: TObject; var CanClose: Boolean);

procedure FormShow(Sender: TObject);

procedure FormCreate(Sender: TObject);

private

{ Private declarations }

/// <summary>

/// 下载的时候不允许关闭窗体

/// </summary>

FAllowFormClose: Boolean;

/// <summary>

/// 接收数据事件

/// </summary>

procedure ReceiveDataEvent(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);

public

{ Public declarations }

end;

var

Form3: TForm3;

implementation

{$R *.dfm}

procedure TForm3.ReceiveDataEvent(const Sender: TObject; AContentLength: Int64; AReadCount: Int64; var Abort: Boolean);

begin

//加上这句界面不卡死.

Application.ProcessMessages;

ProgressBar1.Position := AReadCount;

end;

procedure TForm3.btnStartClick(Sender: TObject);

var

MyHTTPClient: THTTPClient;

MyHTTPResponse: IHTTPResponse;

MyMemoryStream: TMemoryStream;

downloadUrl: string;

begin

MyHTTPClient := THTTPClient.Create;

MyMemoryStream := TMemoryStream.Create;

try

btnStart.Enabled := False;

FAllowFormClose := False;

downloadUrl := Trim(edt1.Text);

//获取文件的大小

MyHTTPResponse := MyHTTPClient.Head(downloadUrl);

ProgressBar1.Position := 0;

ProgressBar1.Max := MyHTTPResponse.ContentLength;

//开始下载,保存到本地

MyHTTPClient.OnReceiveData := ReceiveDataEvent;

MyHTTPResponse := MyHTTPClient.Get(downloadUrl, MyMemoryStream);

if MyHTTPResponse.StatusCode = 200 then

begin

MyMemoryStream.SaveToFile('c:\aa.exe');

ShowMessage('下载完成');

end;

finally

MyHTTPClient.Free;

MyMemoryStream.Free;

//最终都允许关闭窗体

btnStart.Enabled := True;

FAllowFormClose := True;

end;

procedure TForm3.FormCloseQuery(Sender: TObject; var CanClose: Boolean);

begin

CanClose := FAllowFormClose;

end;

procedure TForm3.FormCreate(Sender: TObject);

begin

ReportMemoryLeaksOnShutdown := True;

end;

procedure TForm3.FormShow(Sender: TObject);

begin

btnStart.Enabled := True;

FAllowFormClose := True;

ProgressBar1.Position := 0;

end;

end.

分类：教程

qjson中把记录或类型或泛型数组转换为json字符串

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