如何在Firemonkey中拉伸图像？ [英] How to stretch image in Firemonkey?

问题描述

我想将图像的大小调整为64 * 64的预定义位图，无论其当前尺寸和宽高比如何。我尝试了 Bitmap.ReSize 但保持了宽高比。我尝试 TImage 并将 WrapMode 设置为 iwStretch 。这在一定程度上起作用，因为它确实重新缩放了我想要的图像，但我找不到从 TImage 中获取该图像的方法。 TImage 的位图属性仍包含原始位图。

I would like to resize an image to a predefined bitmap of 64 * 64, regardless of its current dimensions and aspect ratio. I tried Bitmap.ReSize but that keeps the aspect ratio. I tried TImage and set the WrapMode to iwStretch. That works to a certain extent in that it indeed rescales the image as I want it, but I can't find a way to get that image out of the TImage. The Bitmap property of TImage still contains the original bitmap.

有人知道如何从屏幕上显示的 TImage 获取图像吗？或者甚至更好：指向一个能够进行这种调整和拉伸的功能？如果有，我错过了。

Does anybody know how to fetch the Image from a TImage as it is shown on the screen? Or even better: point me to a function that does this kind of resizing and stretching? If there is one, I have missed it.

感谢您的时间。

推荐答案

要在 Fmx 中拉伸图像，您不需要使用 TImage 。我知道你真的不想使用 TImage ，解决方案如下：

To stretch an image in Fmx you don't need to use a TImage. I understand you do not really want to use a TImage, and the solution is as follows:

var
  bmpA, bmpB: TBitmap;
  src, trg: TRectF;
begin
  bmpA := nil;
  bmpB := nil;
  try
    bmpA := TBitmap.Create;
    bmpA.LoadFromFile('C:\tmp\Imgs\149265645.jpg');

    bmpB:= TBitmap.Create;
    bmpB.SetSize(64, 64);

    src := RectF(0, 0, bmpA.Width, bmpA.Height);
    trg := RectF(0, 0, 64, 64);

    bmpB.Canvas.BeginScene;
    bmpB.Canvas.DrawBitmap(bmpA, src, trg, 1);
    bmpB.Canvas.EndScene;

    bmpB.SaveToFile('C:\tmp\Imgs\149265645_take_two.bmp');
  finally
    bmpA.Free;
    bmpB.Free;
  end;
end;

你让 bmpB.Canvas 画出 bmpA 位图并根据 src 和 trg 矩形。

You let the bmpB.Canvas draw the bmpA bitmap and resizing the image at the same time according src and trg rectangles.

这篇关于如何在Firemonkey中拉伸图像？的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！