我必须以主要形式处理一个图像,但是对于inc速度,处理速度很低我使用线程...
我的线程代码:
type
TPaintThread = class(TThread)
Source,Mask :TBitmap ;
image : TImage;
public
procedure SetAll(src,msk:TBitmap;img:TImage);
private
procedure DoWritePix;
var
mBit : TBitmap ;
protected
procedure Execute; override;
end;
implementation
procedure TPaintThread.SetAll(src: TBitmap; msk: TBitmap; img: TImage);
begin
Source := src ;
mask := msk ;
img := img ;
mBit := TBitmap.Create ;
end;
procedure TPaintThread.DoWritePix;
begin
image.Picture.Bitmap := mBit ;
end;
procedure TPaintThread.Execute;
var
i: Integer;
j: Integer;
begin
mBit.Width := Source.Width ;
mBit.Height := Source.Height ;
for i := 1 to Source.Width do
for j := 1 to Source.Width do
begin
// my processing event
end;
// result := mBit ;
// write on form image
Synchronize(DoWritePix);
end;
我在timer
上使用它:
procedure TForm1.tmr1Timer(Sender: TObject);
var
pThread : TPaintThread ;
begin
pThread := TPaintThread.Create(True) ;
pThread.SetAll(MyBmp,mask,img1);
pThread.Resume ;
pThread.FreeOnTerminate := True ;
end;
但我在运行时DoWritePix
出错:
First chance exception at $005A81DE. Exception class $C0000005 with message 'access violation at 0x005a81de: read of address 0x000001b8'. Process myexe.exe (6032)
First chance exception at $754E9617. Exception class EAccessViolation with message 'Access violation at address 005A81DE in module 'myexe.exe'. Read of address 000001B8'. Process myexe.exe (6032)
我的问题:对于主要表单中的编辑图像,这种方式是否正确?如果不是正确的方式访问和写在线程上?如果是,我怎么解决问题?
答案 0 :(得分:8)
此代码错误:
procedure TPaintThread.SetAll(src: TBitmap; msk: TBitmap; img: TImage);
begin
Source := src ;
mask := msk ;
img := img ; // OOPS!
mBit := TBitmap.Create ;
end;
当你写img := img;
时你什么都不做 - 这是一个无操作。你打算写:
image := img;
这就是image
中nil
DoWritePix
解释访问冲突的原因。
遇到运行时错误时不要无助。在调试器下运行代码,让调试器告诉你哪个变量没有初始化。