前言：
1、公司delphi7开发的传统软件还活得好好的，但是大家都知道delphi早已经日落西山了，现在成了后进、追随者。细细算了已经6、7不用了。新的delphixe7呢，没有时间成本去适应和研究。
由于大量使用了第3方的组件和控件，想升级估计是吃力不讨好的事情...
2、保留原有代码，开发新功能可调用远程主机（云主机）的REST ful风格的api,使用Json交换数据。这样就赶上了新潮流，复活了。
由于网上搜索了很多次，发现符合需求的文章很少，这里记录下来，授人以鱼吧。
- delphi7使用Json
- delphi7使用msxml 的“IXMLHttpRequest”对象实现发起 Http post get请求，并传递Json。
- delphi7使用base64编码图片通过Json传递
以下是关键代码：
（1）msxml,SuperObject（第3方,delphi7不自带）, EncdDecd 的引用
（2）XMLHttpRequest的使用：
//提交会员开卡信息
procedure TFormMakeCard.btnOKClick(Sender: TObject);
var
url: string;
resultJson,paramsJson: ISuperObject;
begin
if (CheckInput) then
begin
HttpReq := CoXMLHTTPRequest.Create;
//两种提交请求的方式：Get和Post,Get是通过URL地址传递参数如果是中文需要转码，需要添加时间戳 Post不需要添加时间戳
//get url := ‘http://localhost:5269/api/webmemberapi/NewMemberRegister?timestamp=‘+inttostr(Windows.GetTickCount);
url := ‘http://localhost:5269/api/webmemberapi/NewMemberRegister?‘;
HttpReq.open(‘Post‘, url, False, EmptyParam, EmptyParam);
//http post
HttpReq.setRequestHeader(‘Accept‘, ‘application/json‘);
HttpReq.setRequestHeader(‘Content-Type‘, ‘application/json‘);
//请求主体
try
paramsJson:= GetMemberEntity();
Memo1.Lines.Clear;
memo1.Text := paramsJson.AsString();
HttpReq.send(paramsJson.AsString());
resultJson:=SO(HttpReq.responseText);
if (resultJson<>nil) then
begin
showmessage(resultJson.S[‘Message‘]);
//发卡成功，如果有照片或者签名则执行上传
if (resultJson.B[‘Success‘]=true) then
begin
if (mbPhoto) then
begin
url := ‘http://localhost:5269/api/webmemberapi/UploadMemberImage?‘;
HttpReq.open(‘Post‘, url, False, EmptyParam, EmptyParam);
//http post
HttpReq.setRequestHeader(‘Accept‘, ‘application/json‘);
HttpReq.setRequestHeader(‘Content-Type‘, ‘application/json‘);
paramsJson:=SO();
paramsJson.S[‘ImageFileContent‘]:= BitmapToString(ImageMemberPhoto.Picture.Bitmap);
paramsJson.S[‘ImageCategory‘]:=‘头像‘;
paramsJson.S[‘MemberCardNo‘]:=self.edtCardNo.Text;
HttpReq.send(paramsJson.AsString());
resultJson:=SO(HttpReq.responseText);
end;
if (mbSign) then
begin
url := ‘http://localhost:5269/api/webmemberapi/UploadMemberImage?‘;
HttpReq.open(‘Post‘, url, False, EmptyParam, EmptyParam);
//http post
HttpReq.setRequestHeader(‘Accept‘, ‘application/json‘);
HttpReq.setRequestHeader(‘Content-Type‘, ‘application/json‘);
paramsJson:=SO();
paramsJson.S[‘ImageFileContent‘]:= BitmapToString(ImageMemberSign.Picture.Bitmap);;
paramsJson.S[‘ImageCategory‘]:=‘签名‘;
paramsJson.S[‘MemberCardNo‘]:=self.edtCardNo.Text;
HttpReq.send(paramsJson.AsString());
resultJson:=SO(HttpReq.responseText);
end;
end;
end;
except
on Ex:Exception do
showmessage(Ex.Message);
end;
end;
end;
//XMLHttpRequest实例化
HttpReq := CoXMLHTTPRequest.Create;
//两种提交请求的方式：Get和Post,Get是通过URL地址传递参数如果是中文需要转码，需要添加时间戳 Post不需要添加时间戳
//get url := ‘http://localhost:5269/api/webmemberapi/NewMemberRegister?timestamp=‘+inttostr(Windows.GetTickCount);
url := ‘http://localhost:5269/api/webmemberapi/NewMemberRegister?‘;
// Post或者Get
HttpReq.open(‘Post‘, url, False, EmptyParam, EmptyParam);
//http post **这是关键代码**RequestHeader的设置‘application/json‘,服务器端才能识别为Json
HttpReq.setRequestHeader(‘Accept‘, ‘application/json‘);
HttpReq.setRequestHeader(‘Content-Type‘, ‘application/json‘);
//这是请求的主体
HttpReq.send(paramsJson.AsString());
//把服务器返回的Json字符串反序列化成一个SuperObject对象。
resultJson:=SO(HttpReq.responseText);
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
namespace Com.Aidpoint.MemberApi.Models
{
/// <summary>
/// Action返回值实体
/// </summary>
public class ApiActionResult
{
public bool Success
{
get;
set;
}
public string Message
{
get;
set;
}
public object Result
{
get;
set;
}
}
}
if (resultJson<>nil) then
begin
showmessage(resultJson.S[‘Message‘]);
//发卡成功，如果有照片或者签名则执行上传
if (resultJson.B[‘Success‘]=true) then ...
end
(3)Josn包含base64编码的图片:
//位图文件转Base64字符串
function TFormMakeCard.BitmapToString(img:TBitmap):string;
var
ms:TMemoryStream;
ss:TStringStream;
s:string;
begin
ms := TMemoryStream.Create;
img.SaveToStream(ms);
ss := TStringStream.Create(‘‘);
ms.Position:=0;
EncodeStream(ms,ss);//将内存流编码为base64字符流
s:=ss.DataString;
ms.Free;
ss.Free;
result:=s;
end;
url := ‘http://localhost:5269/api/webmemberapi/UploadMemberImage?‘;
HttpReq.open(‘Post‘, url, False, EmptyParam, EmptyParam);
//http post
HttpReq.setRequestHeader(‘Accept‘, ‘application/json‘);
HttpReq.setRequestHeader(‘Content-Type‘, ‘application/json‘);
paramsJson:=SO();
paramsJson.S[‘ImageFileContent‘]:= BitmapToString(ImageMemberPhoto.Picture.Bitmap);
paramsJson.S[‘ImageCategory‘]:=‘头像‘;
paramsJson.S[‘MemberCardNo‘]:=self.edtCardNo.Text;
HttpReq.send(paramsJson.AsString());
resultJson:=SO(HttpReq.responseText);
(4)服务器端的web api
public ApiActionResult NewMemberRegister([FromBody]MemberDTO memberDTO)
{
//初始化返回值
var result = new ApiActionResult()
{
Success = false,
Result = null,
Message = "操作失败。"
};
if (memberDTO != null)
{
try
{
using (MemberEntities db = new MemberEntities())
{
var dbEntity = CheckMemberExists(memberDTO, db);
if (dbEntity==null)
{
//插入会员表
var entity = DTO2Entity.ConvertToEntityObject<会员表>(memberDTO) as 会员表;
db.AddTo会员表(entity);
//生成储值流水--w:误收,d:积分兑换礼品,f:发新卡,c:储值,q:取款,j:积分消费记录
var detailRec = new 会员储值流水表();
detailRec.会员卡号 = memberDTO.卡号;
detailRec.储值标志 = "f";
detailRec.充值金额 = memberDTO.开卡额.Value;
detailRec.新卡 = "Y";
db.AddTo会员储值流水表(detailRec);
try
{
db.SaveChanges();
result.Success = true;
result.Result = entity;
result.Message = string.Format("操作成功。新发会员卡[{0}],开卡金额:{1}。", entity.自编号, entity.开卡额);
}
catch (Exception ex)
{
var exx = ex.InnerException == null ? ex : ex.InnerException;
throw new Exception(exx.Message);
}
}
else
{
result.Success = false;
result.Result = null;
result.Message = string.Format("卡号[{0}]已经存在。发卡门店[{1}],持卡人:{2}。",dbEntity.自编号,dbEntity.发行分店编号,dbEntity.姓名);
}
}
}
catch (Exception ex)
{
var exx = ex.InnerException == null ? ex : ex.InnerException;
result.Success = false;
result.Result = exx;
result.Message = string.Format("操作异常,异常消息：{0}。", exx.Message);
}
}
return result;
}