在处理过程中如何查看执行的进度？

问题描述

 程序TForm1.ADOQuery1FetchProgress（DataSet：TCustomADODataSet; Progress，
 
 MaxProgress：Integer; var EventStatus：TEventStatus）; 
 
 begin 
 
 Progressbar1.Visible：= true; 
 
 Progressbar1.Max：= MaxProgress; 
 
 Progressbar1.Ppsitian：=进度; 
 
 Progressbar1.Visible：= false; 
 
 end; 
  

但....
我看不到任何效果（此代码不' t执行）

我希望在用户点击数据库中的SEARCH按钮时，显示查询执行的进度，从开始到结束进度条过滤。

按钮onclick代码：

  with ADOQuery1 do 
 
开始
 
 SQL.Clear; 
 
 SQL.Add（'select * from tbl1 where id ='+ Edit1.Text）; 
 
打开; 
 
 end; 
  

但是进度条中没有任何突变，就好像不写任何代码OnFetchProgress事件。

我是否代表你？

解决方案

设置属性之前通话打开的程序

检查此示例

 与ADOQuery1 do 
 begin 
 SQL.Clear; 
 SQL.Add（'select * from tbl1 where id ='+ Edit1.Text）; 
 ExecuteOptions：= [eoAsyncFetch]; 
打开; 
结束
 
 
程序TForm1.ADOQuery1FetchProgress（DataSet：TCustomADODataSet; Progress，
 MaxProgress：Integer; var EventStatus：TEventStatus）; 
 begin 
 ProgressBar1.Max：= MaxProgress; 
 ProgressBar1.Position：=进度; 
 Application.ProcessMessages; 
结束
  

I used the following code in delphi for handle :

procedure TForm1.ADOQuery1FetchProgress(DataSet: TCustomADODataSet; Progress,

  MaxProgress: Integer; var EventStatus: TEventStatus);

begin

    Progressbar1.Visible:=true;

    Progressbar1.Max:=MaxProgress;

    Progressbar1.Ppsitian:=Progress;

    Progressbar1.Visible:=false;

end;

but....I can't see any effect (this code doesn't execute)

I want to show progress of query execution during when the user clicked a button for ٍُSEARCH in database from begining to finish filter in progressbar.

the button onclick codes :

with ADOQuery1 do

begin

SQL.Clear;

SQL.Add('select * from tbl1 where id = '+Edit1.Text);

Open;

end;

but i don't any mutation in the progress bar , as though don't write any code in OnFetchProgress event.

Did i represented you?

解决方案

you must set property ExecuteOptions to eoAsyncFetch before to call the open procedure

check this sample

with ADOQuery1 do
begin
 SQL.Clear;
 SQL.Add('select * from tbl1 where id = '+Edit1.Text);
 ExecuteOptions:=[eoAsyncFetch];
 Open;
end;


procedure TForm1.ADOQuery1FetchProgress(DataSet: TCustomADODataSet; Progress,
  MaxProgress: Integer; var EventStatus: TEventStatus);
begin
  ProgressBar1.Max      :=MaxProgress;
  ProgressBar1.Position :=Progress;
  Application.ProcessMessages;
end;

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