我觉得我的失败在于搜索关键词,因为这方面的信息应该很普遍。基本上,我正在寻找在调整表单大小时调整多个组件的常见解决方案和最佳实践。
我有一个基于
屏幕截图:
我有一个基于
TScrollBox
的组件表单。滚动框包含在运行时动态添加的行。它们基本上是子组件。每个行左侧有一个图像,右侧有一个备忘录。高度根据图像的宽度和长宽比设置。在滚动框调整大小时,循环设置行的宽度,从而触发行自身的内部调整大小。如果高度发生变化,循环还会设置相对顶部位置。屏幕截图:
大约16行表现良好。我的目标更接近32行,这非常卡顿,可能会将一个核心的使用率提高到100%。
我已经尝试过:
- 添加了一个检查,以防止新的调整大小在之前完成之前开始。如果发生了,它会回答,并且有时确实会发生。
- 我尝试防止每30毫秒调整大小一次,这将允许每秒绘制30帧。效果不稳定。
- 将行基本组件从TPanel更改为TWinControl。不确定使用Panel是否存在性能惩罚,但这是一个老习惯。
- 使用和不使用双缓冲。
我希望在调整大小期间允许行调整大小,以预览行中图像的大小。这消除了一个显而易见的解决方案,在某些应用程序中是可以接受的损失。
现在,行的调整大小代码在内部完全动态,并基于每个图像的尺寸。我计划尝试的下一件事情是基本上指定纵横比、最大宽度/高度,这取决于集合中最大的图像。这应该减少每行的计算量。但似乎问题更多的是调整大小事件和循环本身?
组件的完整单元代码:
unit rPBSSVIEW;
interface
uses
Classes, Controls, Forms, ExtCtrls, StdCtrls, Graphics, SysUtils, rPBSSROW, Windows, Messages;
type
TPBSSView = class(TScrollBox)
private
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure ResizeRows(Sender: TObject);
procedure AddRow(FileName: String);
procedure FillRow(Row: Integer; ImageStream: TMemoryStream);
end;
var
PBSSrow: Array of TPBSSRow;
Resizingn: Boolean;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Standard', [TScrollBox]);
end;
procedure TPBSSView.AddRow(FileName: String);
begin
SetLength(PBSSrow,(Length(PBSSrow) + 1));
PBSSrow[Length(PBSSrow)-1] := TPBSSRow.create(self);
With PBSSrow[Length(PBSSrow)-1] do
begin
Left := 2;
if (Length(PBSSrow)-1) = 0 then Top := 2 else Top := ((PBSSRow[Length(PBSSRow) - 2].Top + PBSSRow[Length(PBSSRow) - 2].Height) + 2);
Width := (inherited ClientWidth - 4);
Visible := True;
Parent := Self;
PanelLeft.Caption := FileName;
end;
end;
procedure TPBSSView.FillRow(Row: Integer; ImageStream: TMemoryStream);
begin
PBSSRow[Row].LoadImageFromStream(ImageStream);
end;
procedure TPBSSView.ResizeRows(Sender: TObject);
var
I, X: Integer;
begin
if Resizingn then exit
else
begin
Resizingn := True;
HorzScrollBar.Visible := False;
X := (inherited ClientWidth - 4);
if Length(PBSSrow) > 0 then
for I := 0 to Length(PBSSrow) - 1 do
Begin
PBSSRow[I].Width := X; //Set Width
if not (I = 0) then //Move all next ones down.
begin
PBSSRow[I].Top := (PBSSRow[(I - 1)].Top + PBSSRow[(I - 1)].Height) + 2;
end;
Application.ProcessMessages;
End;
HorzScrollBar.Visible := True;
Resizingn := False;
end;
end;
constructor TPBSSView.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
OnResize := ResizeRows;
DoubleBuffered := True;
VertScrollBar.Tracking := True;
Resizingn := False;
end;
destructor TPBSSView.Destroy;
begin
inherited;
end;
end.
行代码:
unit rPBSSROW;
interface
uses
Classes, Controls, Forms, ExtCtrls, StdCtrls, Graphics, pngimage, SysUtils;
type
TPBSSRow = class(TWinControl)
private
FImage: TImage;
FPanel: TPanel;
FMemo: TMemo;
FPanelLeft: TPanel;
FPanelRight: TPanel;
FImageWidth: Integer;
FImageHeight: Integer;
public
constructor Create(AOwner: TComponent); override;
destructor Destroy; override;
procedure MyPanelResize(Sender: TObject);
procedure LeftPanelResize(Sender: TObject);
published
procedure LoadImageFromStream(ImageStream: TMemoryStream);
property Image: TImage read FImage;
property Panel: TPanel read FPanel;
property PanelLeft: TPanel read FPanelLeft;
property PanelRight: TPanel read FPanelRight;
end;
procedure Register;
implementation
procedure Register;
begin
RegisterComponents('Standard', [TWinControl]);
end;
procedure TPBSSRow.MyPanelResize(Sender: TObject);
begin
if (Width - 466) <= FImageWidth then FPanelLeft.Width := (Width - 466)
else FPanelLeft.Width := FImageWidth;
FPanelRight.Width := (Width - FPanelLeft.Width);
end;
procedure TPBSSRow.LeftPanelResize(Sender: TObject);
var
AspectRatio: Extended;
begin
FPanelRight.Left := (FPanelLeft.Width);
//Enforce Info Minimum Height or set Height
if FImageHeight > 0 then AspectRatio := (FImageHeight/FImageWidth) else
AspectRatio := 0.4;
if (Round(AspectRatio * FPanelLeft.Width)) >= 212 then
begin
Height := (Round(AspectRatio * FPanelLeft.Width));
FPanelLeft.Height := Height;
FPanelRight.Height := Height;
end
else
begin
Height :=212;
FPanelLeft.Height := Height;
FPanelRight.Height := Height;
end;
if Fimage.Height >= FImageHeight then FImage.Stretch := False else Fimage.Stretch := True;
if Fimage.Width >= FImageWidth then FImage.Stretch := False else Fimage.Stretch := True;
end;
procedure TPBSSRow.LoadImageFromStream(ImageStream: TMemoryStream);
var
P: TPNGImage;
n: Integer;
begin
P := TPNGImage.Create;
ImageStream.Position := 0;
P.LoadFromStream(ImageStream);
FImage.Picture.Assign(P);
FImageWidth := P.Width;
FImageHeight := P.Height;
end;
constructor TPBSSRow.Create(AOwner: TComponent);
begin
inherited Create(AOwner);
BevelInner := bvNone;
BevelOuter := bvNone;
BevelKind := bkNone;
Color := clWhite;
OnResize := MyPanelResize;
DoubleBuffered := True;
//Left Panel for Image
FPanelLeft := TPanel.Create(Self);
with FPanelLeft do
begin
SetSubComponent(true);
Align := alLeft;
Parent := Self;
//SetBounds(0,0,100,100);
ParentBackground := False;
Color := clBlack;
Font.Color := clLtGray;
Constraints.MinWidth := 300;
BevelInner := bvNone;
BevelOuter := bvNone;
BevelKind := bkNone;
BorderStyle := bsNone;
OnResize := LeftPanelResize;
end;
//Image for left panel
FImage := TImage.Create(Self);
FImage.SetSubComponent(true);
FImage.Align := alClient;
FImage.Parent := FPanelLeft;
FImage.Center := True;
FImage.Stretch := True;
FImage.Proportional := True;
//Right Panel for Info
FPanelRight := TPanel.Create(Self);
with FPanelRight do
begin
SetSubComponent(true);
Parent := Self;
Padding.SetBounds(2,5,5,2);
BevelInner := bvNone;
BevelOuter := bvNone;
BevelKind := bkNone;
BorderStyle := bsNone;
Color := clLtGray;
end;
//Create Memo in Right Panels
FMemo := TMemo.create(self);
with FMemo do
begin
SetSubComponent(true);
Parent := FPanelRight;
Align := alClient;
BevelOuter := bvNone;
BevelInner := bvNone;
BorderStyle := bsNone;
Color := clLtGray;
end;
end;
destructor TPBSSRow.Destroy;
begin
inherited;
end;
end.
LockWindowUpdate
的文档。这是那些API函数之一,通常会像滥用ProcessMessages
一样被滥用。 - David Heffernan