我觉得到目前为止我的失败在于搜索词，因为这方面的信息必须非常普遍。基本上，我正在寻找在调整表单大小时对多个组件执行调整大小时的通用解决方案和最佳实践。
我有一个表单，其组件基于TScrollBox。 ScrollBox 包含在运行时动态添加的行。它们基本上是一个子组件。每张照片的左侧都有一张图片，右侧有一份备忘录。高度是根据图像的宽度和纵横比设置的。调整滚动框的大小时，循环会设置行的宽度，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。
截屏：
大约 16 行表现良好。我的目标是接近 32 行，这非常不稳定，并且可以将核心固定在 100% 使用率。
我努力了：
- 添加了一项检查，以防止在前一个调整大小尚未完成时开始新的调整大小。如果发生的话它就会回答，而且有时确实会发生。
- 我尝试阻止它调整大小的频率超过每 30 毫秒，这样可以每秒绘制 30 帧。结果好坏参半。
- 将行基础组件从 TPanel 更改为 TWinControl。不确定使用面板是否会降低性能，但这是一个老习惯。
- 有和没有双缓冲。
我希望允许在调整大小期间进行行大小调整，作为图像在行中的大小的预览。这就消除了一种明显的解决方案，而这种解决方案在某些应用中是可以接受的损失。
现在，行内部的调整大小代码是完全动态的，并且基于每个图像的尺寸。我计划尝试的下一步是根据集合中最大的图像来指定长宽比、最大宽度/高度。这应该会减少每行的数学量。但问题似乎更多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.
