前面说了basic4android 直接访问kbmMW server 的方法，由于javaclient 不直接支持服务器端数据库的操作，
要显示数据的内容就需要通过JSON 方式来转换。今天就大概介绍一下转换的办法。
首先要在服务器端把数据库转换为JSON ，为了方便，我修改了一下前面的转换过程。
function Txalionsrv.datatojson(intablename: string): string; var alljson: ISuperObject; datajson: ISuperObject; recordjson: ISuperObject; totalcount: string; starti, endi, i: integer; begin alljson := TSuperObject.Create(stobject); cx.sql.clear; cx.sql.add('select count(*) from (' + intablename + ')'); try cx.Open; except on E:Exception do begin result:='数据库打开错误!'+e.Message; exit; end; end; totalcount := cx.fields[0].AsString; if totalcount > '0' then begin datajson := TSuperObject.Create(starray); with cx do begin sql.clear; sql.Add(' select * from ( '+intablename+' )'); try Open; except result:='数据库打开错误!2'; exit; end; while not eof do begin recordjson := TSuperObject.Create(stobject); for i := 0 to fields.Count - 1 do begin recordjson.s[fields[i].FieldName] := fields[i].AsString; end; datajson.o[''] := recordjson; recordjson := nil; next; end; end; alljson.o['topics'] := datajson; alljson.s['totalCount'] := totalcount; datajson := nil; end; result := alljson.AsJSon(); alljson := nil; end; function Txalionsrv.Performgetdata(ClientIdent:TkbmMWClientIdentity; const Args:array of Variant):Variant; begin result:=datatojson(args[0]); end; function Txalionsrv.ProcessRequest(const Func: string; const ClientIdent: TkbmMWClientIdentity; const Args: array of Variant): Variant; var AFunc:string; begin AFunc:=UpperCase(Func); if AFunc='SUMALL' then Result:=Performsumall(ClientIdent,Args) else if AFunc='GETIMG' then Result:=Performgetimg(ClientIdent,Args) else if AFunc='GETDATA' then result:=Performgetdata(ClientIdent,Args) end;
然后运行服务器端。
客户端需要在B4A 上加一个显示数据的activity
主单元的代码为
'Activity module Sub Process_Globals 'These global variables will be declared once when the application starts. 'These variables can be accessed from all modules. Dim sdata As String End Sub Sub Globals 'These global variables will be redeclared each time the activity is created. 'These variables can only be accessed from this module. Dim SimpleClient As TkbmMWClient Dim Ip As EditText Dim Port As EditText Dim mLog As EditText End Sub Sub Activity_Create(FirstTime As Boolean) Activity.LoadLayout("Main") Ip.Text = "192.168.1.215" Port.Text = "3000" End Sub Sub Activity_Resume End Sub Sub Activity_Pause (UserClosed As Boolean) End Sub Sub ConnectBtn_Click SimpleClient.Connect(Ip.Text,Port.Text) End Sub Sub SendBtn_Click Dim args(2) As String args(0)="select Xh,Xm,yanglaoxy,yanglaogr from rssj" sdata=SimpleClient.SendRequest ("xalion_srv","","GETDATA",args) StartActivity(bmxinxi) End Sub
bmxinxi的代码如下：
'Activity module Sub Process_Globals 'These global variables will be declared once when the application starts. 'These variables can be accessed from all modules. End Sub Sub Globals 'These global variables will be redeclared each time the activity is created. 'These variables can only be accessed from this module. Dim SV As ScrollView Dim Header As Panel Dim Footer As Panel Dim Table As Panel Dim NumberOfColumns, RowHeight, RowHeight_1, ColumnWidth, ColumnWidth_1 As Int Dim HeaderColor, LineColor, CellColor, FontColor, HeaderFontColor As Int Dim ColLineWidth, RowLineWidth As Int Dim FontSize As Float Type RowCol (Row As Int, Col As Int) Dim Alignment As Int Dim SelectedRow As Int Dim SelectedRowColor As Int : SelectedRowColor=Colors.LightGray 'Table settings HeaderColor = Colors.Gray NumberOfColumns = 4 'will be overwritten when loading from CSV file. ColLineWidth = 1dip RowLineWidth = 1dip RowHeight_1 = 30dip RowHeight=RowHeight_1+RowLineWidth LineColor = Colors.Black CellColor = Colors.White FontColor = Colors.Black HeaderFontColor = Colors.White FontSize = 14 Alignment = Gravity.CENTER 'change to Gravity.LEFT or Gravity.RIGHT for other alignments. End Sub Sub Activity_Create(FirstTime As Boolean) SV.Initialize(0) ' SV.Color=Colors.Transparent SV.Panel.Color=Colors.Black Table = SV.Panel Table.Color = LineColor Activity.AddView(SV, 1%x, 10%y, 99%x, 80%y) ColumnWidth = SV.Width / NumberOfColumns ColumnWidth_1 = ColumnWidth-ColLineWidth SelectedRow = -1 loadxinxi(Main.sdata) End Sub Sub loadxinxi(s As String) Dim JSON As JSONParser Dim Master As Map Dim records As List Dim XINXI As Map Dim recordcount As String ClearAll Dim h(4) As String h(0)="序号" h(1)="姓名" h(2)="学院" h(3)="个人" NumberOfColumns = h.Length ColumnWidth = SV.Width / NumberOfColumns 'update the columns widths ColumnWidth_1 = ColumnWidth-ColLineWidth SetHeader(h) JSON.Initialize(s) Master = JSON.NextObject records=Master.Get("topics") Dim data(4) As String For i=0 To records.Size-1 Dim row() As String XINXI=records.Get(i) data(0)=XINXI.Get("XH") data(1)=XINXI.get("XM") data(2)=XINXI.get("YANGLAOXY") data(3)=XINXI.get("YANGLAOGR") row =data AddRow(row) Next recordcount=Master.Get("totalCount") h(0)="合计" h(1)=recordcount h(2)="" h(3)="" SetFooter(h) Activity.Title="职工信息" End Sub Sub Cell_Click Dim rc As RowCol Dim l As Label Dim l0 As Label l = Sender rc = l.Tag SelectRow(rc.Row) l0=GetView(rc.Row,0) 'activity.Title = "Cell clicked: (" & rc.Row & ", " & rc.Col & l0.Text &")" myxh=l0.Text End Sub Sub Header_Click Dim l As Label Dim col As Int l = Sender col = l.Tag Activity.Title = "Header clicked: " & col End Sub Sub SelectRow(Row As Int) 'remove the color of previously selected row If SelectedRow > -1 Then For col = 0 To NumberOfColumns - 1 GetView(SelectedRow, col).Color = CellColor Next End If SelectedRow = Row For col = 0 To NumberOfColumns - 1 GetView(Row, col).Color = SelectedRowColor Next End Sub 'Returns the label in the specific cell Sub GetView(Row As Int, Col As Int) As Label Dim l As Label l = Table.GetView(Row * NumberOfColumns + Col) Return l End Sub 'Adds a row to the table Sub AddRow(Values() As String) If Values.Length <> NumberOfColumns Then Log("Wrong number of values.") Return End If Dim lastRow As Int lastRow = NumberOfRows For i = 0 To NumberOfColumns - 1 Dim l As Label l.Initialize("cell") l.Text = Values(i) l.Gravity = Alignment l.TextSize = FontSize l.TextColor = FontColor l.Color=Colors.White Dim rc As RowCol rc.Initialize rc.Col = i rc.Row = lastRow l.Tag = rc Table.AddView(l, ColumnWidth * i, RowHeight * lastRow, ColumnWidth_1, RowHeight_1) Next Table.Height = NumberOfRows * RowHeight End Sub 'Set the headers values Sub SetHeader(Values() As String) If Header.IsInitialized Then Return 'should only be called once Header.Initialize("") For i = 0 To NumberOfColumns - 1 Dim l As Label l.Initialize("header") l.Text = Values(i) l.Gravity = Gravity.CENTER l.TextSize = FontSize l.Color = HeaderColor l.TextColor = HeaderFontColor l.Tag = i Header.AddView(l, ColumnWidth * i, 0, ColumnWidth_1, RowHeight_1) Next Activity.AddView(Header, SV.Left, SV.Top - RowHeight, SV.Width, RowHeight) End Sub Sub SetFooter(Values() As String) If Footer.IsInitialized Then Return 'should only be called once Footer.Initialize("") For i = 0 To NumberOfColumns - 1 Dim l As Label l.Initialize("footer") l.Text = Values(i) l.Gravity = Gravity.CENTER l.TextSize = FontSize l.Color = HeaderColor l.TextColor = HeaderFontColor l.Tag = i Footer.AddView(l, ColumnWidth * i, 0, ColumnWidth_1, RowHeight_1) Next Activity.AddView(Footer, SV.Left, SV.Top+SV.Height, SV.Width, RowHeight) End Sub Sub NumberOfRows As Int Return Table.NumberOfViews / NumberOfColumns End Sub 'Sets the value of the given cell Sub SetCell(Row As Int, Col As Int, Value As String) GetView(Row, Col).Text = Value End Sub 'Gets the value of the given cell Sub GetCell(Row As Int, Col As Int) As String Return GetView(Row, Col).Text End Sub 'Clears the table Sub ClearAll For i = Table.NumberOfViews -1 To 0 Step -1 Table.RemoveViewAt(i) Next Table.Height = 0 SelectedRow = -1 End Sub Sub Activity_Resume End Sub Sub Activity_Pause (UserClosed As Boolean) End Sub
现在运行客户端，就会回来下面界面，而且还支持滑动显示呢.
注意：本文纯粹是为了演示目的，在实际操作中由于JSON 数据量比较大，因此在显示数据时
要考虑到分页，同时可以通过压缩来减少网络流量。