Delphi Thread线程错误：Canvas doesn't allow drawing

Delphi Thread线程错误：Canvas doesn't allow drawing

错误原因：在使用Thread线程时，所有UI界面的代码都要进行同步，否则，就会出现这个错误。

解决方法：

TThread.Synchronize();

Synchronize 源码：　　

procedure TThread.Synchronize(Method: TThreadMethod);
begin
  FSynchronize.FThread := Self;
  FSynchronize.FSynchronizeException := nil;
  FSynchronize.FMethod := Method;
  Synchronize(@FSynchronize);
end;

class procedure TThread.Synchronize(AThread: TThread; AMethod: TThreadMethod);
var
  SyncRec: TSynchronizeRecord;
begin
  if AThread <> nil then
    AThread.Synchronize(AMethod)
  else
  begin
    SyncRec.FThread := nil;
    SyncRec.FSynchronizeException := nil;
    SyncRec.FMethod := AMethod;
    TThread.Synchronize(@SyncRec);
  end;
end;

class procedure TThread.StaticSynchronize(AThread: TThread; AMethod: TThreadMethod);
begin
  Synchronize(AThread, AMethod);
end;

　　

 

 

创建时间：2020.10.13　　更新时间：