我如何 运行 在后台循环程序?
How can i run a loop procedure in background?
我创建了一个过程来更新 SQLite 数据库。过程 运行 循环直到列表完成。问题是,当我运行程序时,程序停止响应
我怎样才能 运行 这个程序在后台运行而不会使程序崩溃?
procedure TForm1.domainupdate;
var
I, J, K, svr: integer ;
domain1, domain2: string ;
expiry: string;
sl: TStringList;
fs: TFormatSettings;
s: string;
dt: TDatetime;
ds : TFormatSettings;
memo : tmemo;
begin
DM.Qdomains.First;
while not DM.Qdomains.Eof do begin
for J := Length (DM.Qdomains.FieldByName('domain').AsString) downto 2 do begin
if DM.Qdomains.FieldByName('domain').AsString [J] = '.' then begin // search host.co.uk
if domain1 = '' then
domain1 := Copy (DM.Qdomains.FieldByName('domain').AsString, J + 1, 99) + IcsSpace
// found uk
else begin
domain2 := Copy (DM.Qdomains.FieldByName('domain').AsString, J + 1, 99) + IcsSpace ;
// found co.uk
Break ;
end;
end;
end;
FWhoisServers := TStringList.Create;
for I := 0 to Length(WhoisNames) - 1 do
FWhoisServers.add(WhoisNames[I]);
FHost := 'whois.ripe.net' ;
K := -1 ;
if FWhoisServers.Count > 0 then begin
for I := 0 to FWhoisServers.Count - 1 do
begin
if (Pos (domain1, FWhoisServers [I]) = 1) then K := I ;
if (Pos (domain2, FWhoisServers [I]) = 1) then
begin
K := I ;
break ;
end ;
end;
if K >= 0 then begin
J := Pos (IcsSpace, FWhoisServers [K]) ;
end;
end;
if K < 0 then begin
end;
IdWhois1.host := Copy (FWhoisServers [K], J + 1, 99) ;
Memo:=TMemo.Create(nil);
Memo.Visible:=false;
memo.Lines.text := IdWhois1.WhoIs(DM.Qdomains.FieldByName('domain').AsString);
begin
sl := TStringList.Create;
try
sl.Assign(Memo.Lines);
for I := 0 to sl.Count-1 do begin
sl[I] := TrimLeft(sl[I]);
end;
sl.NameValueSeparator := ':';
for I := Low(FieldNames) to High(FieldNames) do begin
expiry := Trim(sl.Values[FieldNames[I]]);
if expiry <> '' then
Break;
end;
finally
sl.Free;
end;
if expiry = '' then
exit
else
s := expiry;
fs := TFormatSettings.Create;
fs.DateSeparator := '-';
fs.TimeSeparator := ':';
fs.shortdateformat := 'yyyy-mm-dd';
fs.ShortTimeFormat := 'hh:nn:ss';
dt := StrToDatetime(s, fs);
ds.DateSeparator := '/';
ds.TimeSeparator := ':';
ds.ShortDateFormat := 'dd/mm/yyyy';
ds.longtimeFormat := 'hh:mm:ss';
end;
end;
//********************************************************
//********************************************************
//if edit1.text <> '' then DM.Qdomains.Open;
DM.Qdomains.Edit;
DM.Qdomains.FieldByName('domain').AsString :=
DM.Qdomains.FieldByName('domain').AsString;
DM.Qdomains.FieldByName('expiry').AsString := datetimetostr(dt, ds);
DM.Qdomains.FieldByName('whois').AsString :=
IdWhois1.WhoIs(DM.Qdomains.FieldByName('domain').AsString);
DM.Qdomains.FieldByName('update').AsString := DatetimeToStr(now);
DM.Qdomains.Post;
DM.Qdomains.Next;
end;
将逻辑移动到一个单独的工作线程中,仅在绝对需要时才与主 UI 线程同步(即显示结果)。如果您计划在 运行 Android 上编写此代码,则无论如何都需要执行此操作,因为您无法在 UI 主线程上执行网络操作。
此外,删除代码正在创建的 TMemo
,它根本不需要。您使用它的全部目的是将 Whois 结果解析为 TStringList
,您可以直接这样做。而且,您正在泄露 TMemo
并且永远不会向用户展示它。
试试像这样的东西:
procedure TForm1.DomainUpdate;
var
I, J, K: Integer;
domain, domain1, domain2, host, whois, expiry: string;
sl: TStringList;
fs, ds: TFormatSettings;
dt: TDatetime;
begin
// TODO: perform the DB query here instead of in the main thread...
DM.Qdomains.First;
while not DM.Qdomains.Eof do begin
domain := DM.Qdomains.FieldByName('domain').AsString;
domain1 := '';
domain2 := '';
for J := Length(domain) downto 2 do begin
if domain[J] = '.' then begin // search host.co.uk
if domain1 = '' then
domain1 := Copy(domain, J + 1, MaxInt) + IcsSpace
// found uk
else begin
domain2 := Copy(domain, J + 1, MaxInt) + IcsSpace;
// found co.uk
Break;
end;
end;
end;
FWhoisServers := TStringList.Create;
try
for I := 0 to Length(WhoisNames) - 1 do
FWhoisServers.Add(WhoisNames[I]);
host := 'whois.ripe.net';
K := -1;
if FWhoisServers.Count > 0 then begin
for I := 0 to FWhoisServers.Count - 1 do
begin
if (Pos(domain1, FWhoisServers[I]) = 1) then K := I;
if (Pos(domain2, FWhoisServers[I]) = 1) then
begin
K := I;
Break;
end;
end;
if K >= 0 then begin
J := Pos(IcsSpace, FWhoisServers[K]);
host := Copy(FWhoisServers[K], J + 1, MaxInt);
end;
end;
IdWhois1.Host := host;
finally
FWhoisServers.Free;
end;
expiry := '';
sl := TStringList.Create;
try
whois := IdWhois1.WhoIs(domain);
sl.Text := whois;
for I := 0 to sl.Count-1 do begin
sl[I] := TrimLeft(sl[I]);
end;
sl.NameValueSeparator := ':';
for I := Low(FieldNames) to High(FieldNames) do begin
expiry := Trim(sl.Values[FieldNames[I]]);
if expiry <> '' then
Break;
end;
finally
sl.Free;
end;
if expiry <> '' then begin
fs := TFormatSettings.Create;
fs.DateSeparator := '-';
fs.TimeSeparator := ':';
fs.ShortDateFormat := 'yyyy-mm-dd';
fs.ShortTimeFormat := 'hh:nn:ss';
dt := StrToDateTime(expiry, fs);
ds := TFormatSettings.Create;
ds.DateSeparator := '/';
ds.TimeSeparator := ':';
ds.ShortDateFormat := 'dd/mm/yyyy';
ds.LongTimeFormat := 'hh:mm:ss';
DM.Qdomains.Edit;
try
DM.Qdomains.FieldByName('domain').AsString := domain;
DM.Qdomains.FieldByName('expiry').AsString := DateTimeToStr(dt, ds);
DM.Qdomains.FieldByName('whois').AsString := whois;
DM.Qdomains.FieldByName('update').AsString := DateTimeToStr(Now);
DM.Qdomains.Post;
except
DM.Qdomains.Cancel;
raise;
end;
end;
DM.Qdomains.Next;
end;
end;
...
TThread.CreateAnonymousThread(DomainUpdate).Start;
我创建了一个过程来更新 SQLite 数据库。过程 运行 循环直到列表完成。问题是,当我运行程序时,程序停止响应
我怎样才能 运行 这个程序在后台运行而不会使程序崩溃?
procedure TForm1.domainupdate;
var
I, J, K, svr: integer ;
domain1, domain2: string ;
expiry: string;
sl: TStringList;
fs: TFormatSettings;
s: string;
dt: TDatetime;
ds : TFormatSettings;
memo : tmemo;
begin
DM.Qdomains.First;
while not DM.Qdomains.Eof do begin
for J := Length (DM.Qdomains.FieldByName('domain').AsString) downto 2 do begin
if DM.Qdomains.FieldByName('domain').AsString [J] = '.' then begin // search host.co.uk
if domain1 = '' then
domain1 := Copy (DM.Qdomains.FieldByName('domain').AsString, J + 1, 99) + IcsSpace
// found uk
else begin
domain2 := Copy (DM.Qdomains.FieldByName('domain').AsString, J + 1, 99) + IcsSpace ;
// found co.uk
Break ;
end;
end;
end;
FWhoisServers := TStringList.Create;
for I := 0 to Length(WhoisNames) - 1 do
FWhoisServers.add(WhoisNames[I]);
FHost := 'whois.ripe.net' ;
K := -1 ;
if FWhoisServers.Count > 0 then begin
for I := 0 to FWhoisServers.Count - 1 do
begin
if (Pos (domain1, FWhoisServers [I]) = 1) then K := I ;
if (Pos (domain2, FWhoisServers [I]) = 1) then
begin
K := I ;
break ;
end ;
end;
if K >= 0 then begin
J := Pos (IcsSpace, FWhoisServers [K]) ;
end;
end;
if K < 0 then begin
end;
IdWhois1.host := Copy (FWhoisServers [K], J + 1, 99) ;
Memo:=TMemo.Create(nil);
Memo.Visible:=false;
memo.Lines.text := IdWhois1.WhoIs(DM.Qdomains.FieldByName('domain').AsString);
begin
sl := TStringList.Create;
try
sl.Assign(Memo.Lines);
for I := 0 to sl.Count-1 do begin
sl[I] := TrimLeft(sl[I]);
end;
sl.NameValueSeparator := ':';
for I := Low(FieldNames) to High(FieldNames) do begin
expiry := Trim(sl.Values[FieldNames[I]]);
if expiry <> '' then
Break;
end;
finally
sl.Free;
end;
if expiry = '' then
exit
else
s := expiry;
fs := TFormatSettings.Create;
fs.DateSeparator := '-';
fs.TimeSeparator := ':';
fs.shortdateformat := 'yyyy-mm-dd';
fs.ShortTimeFormat := 'hh:nn:ss';
dt := StrToDatetime(s, fs);
ds.DateSeparator := '/';
ds.TimeSeparator := ':';
ds.ShortDateFormat := 'dd/mm/yyyy';
ds.longtimeFormat := 'hh:mm:ss';
end;
end;
//********************************************************
//********************************************************
//if edit1.text <> '' then DM.Qdomains.Open;
DM.Qdomains.Edit;
DM.Qdomains.FieldByName('domain').AsString :=
DM.Qdomains.FieldByName('domain').AsString;
DM.Qdomains.FieldByName('expiry').AsString := datetimetostr(dt, ds);
DM.Qdomains.FieldByName('whois').AsString :=
IdWhois1.WhoIs(DM.Qdomains.FieldByName('domain').AsString);
DM.Qdomains.FieldByName('update').AsString := DatetimeToStr(now);
DM.Qdomains.Post;
DM.Qdomains.Next;
end;
将逻辑移动到一个单独的工作线程中,仅在绝对需要时才与主 UI 线程同步(即显示结果)。如果您计划在 运行 Android 上编写此代码,则无论如何都需要执行此操作,因为您无法在 UI 主线程上执行网络操作。
此外,删除代码正在创建的 TMemo
,它根本不需要。您使用它的全部目的是将 Whois 结果解析为 TStringList
,您可以直接这样做。而且,您正在泄露 TMemo
并且永远不会向用户展示它。
试试像这样的东西:
procedure TForm1.DomainUpdate;
var
I, J, K: Integer;
domain, domain1, domain2, host, whois, expiry: string;
sl: TStringList;
fs, ds: TFormatSettings;
dt: TDatetime;
begin
// TODO: perform the DB query here instead of in the main thread...
DM.Qdomains.First;
while not DM.Qdomains.Eof do begin
domain := DM.Qdomains.FieldByName('domain').AsString;
domain1 := '';
domain2 := '';
for J := Length(domain) downto 2 do begin
if domain[J] = '.' then begin // search host.co.uk
if domain1 = '' then
domain1 := Copy(domain, J + 1, MaxInt) + IcsSpace
// found uk
else begin
domain2 := Copy(domain, J + 1, MaxInt) + IcsSpace;
// found co.uk
Break;
end;
end;
end;
FWhoisServers := TStringList.Create;
try
for I := 0 to Length(WhoisNames) - 1 do
FWhoisServers.Add(WhoisNames[I]);
host := 'whois.ripe.net';
K := -1;
if FWhoisServers.Count > 0 then begin
for I := 0 to FWhoisServers.Count - 1 do
begin
if (Pos(domain1, FWhoisServers[I]) = 1) then K := I;
if (Pos(domain2, FWhoisServers[I]) = 1) then
begin
K := I;
Break;
end;
end;
if K >= 0 then begin
J := Pos(IcsSpace, FWhoisServers[K]);
host := Copy(FWhoisServers[K], J + 1, MaxInt);
end;
end;
IdWhois1.Host := host;
finally
FWhoisServers.Free;
end;
expiry := '';
sl := TStringList.Create;
try
whois := IdWhois1.WhoIs(domain);
sl.Text := whois;
for I := 0 to sl.Count-1 do begin
sl[I] := TrimLeft(sl[I]);
end;
sl.NameValueSeparator := ':';
for I := Low(FieldNames) to High(FieldNames) do begin
expiry := Trim(sl.Values[FieldNames[I]]);
if expiry <> '' then
Break;
end;
finally
sl.Free;
end;
if expiry <> '' then begin
fs := TFormatSettings.Create;
fs.DateSeparator := '-';
fs.TimeSeparator := ':';
fs.ShortDateFormat := 'yyyy-mm-dd';
fs.ShortTimeFormat := 'hh:nn:ss';
dt := StrToDateTime(expiry, fs);
ds := TFormatSettings.Create;
ds.DateSeparator := '/';
ds.TimeSeparator := ':';
ds.ShortDateFormat := 'dd/mm/yyyy';
ds.LongTimeFormat := 'hh:mm:ss';
DM.Qdomains.Edit;
try
DM.Qdomains.FieldByName('domain').AsString := domain;
DM.Qdomains.FieldByName('expiry').AsString := DateTimeToStr(dt, ds);
DM.Qdomains.FieldByName('whois').AsString := whois;
DM.Qdomains.FieldByName('update').AsString := DateTimeToStr(Now);
DM.Qdomains.Post;
except
DM.Qdomains.Cancel;
raise;
end;
end;
DM.Qdomains.Next;
end;
end;
...
TThread.CreateAnonymousThread(DomainUpdate).Start;