显示URL中的图像 [英] Display an image from URL

问题描述

我需要从URL获取图像并在视图中显示。怎么能在Cincom Smalltalk中做到这一点？
例如，我有这个图片网址：

I need get an image from a URL and display in a view. How can do this in Cincom Smalltalk? For example, I have this image URL:

http://news.bbcimg.co.uk/media/images/64001000/jpg/_64001280_63976026.jpg

我希望显示图像。我尝试：

And I wish display the image. I try:

|req content reader|
req := HttpRequest
    get:'http://news.bbcimg.co.uk/media/images/64001000/jpg/_64001280_63976026.jpg' asURI.
content:=req execute.
reader := JPEGImageReader new.
reader from: content byteSource.

但它不起作用。 Cincom Smalltalk说：

But it doesn't work. Cincom Smalltalk says:

图像不完整或部分损坏预期的JFIF标记。

Image incomplete or partially corrupted JFIF marker expected.

执行时： JPEGImageReader>> parseFirstMarker 。

推荐答案

byteSource方法返回已经定位到文件末尾的流。当JPEG阅读器开始阅读时，我点击结束并中止。

The "byteSource" method is returning a stream that's already positioned to the end of file. When the JPEG reader starts to read, I hits the end and aborts.

你真的不应该使用byteSource方法。如果URI的内容被压缩，您将无法正确解压缩它们。您应该获取byteContents并在该结果上打开一个readStream，如下所示：

You really shouldn't be using the byteSource method. If the contents of the URI are compressed, you won't get them properly decompressed. You should fetch the byteContents and open a readStream on that result as follows:

|req content reader image |
req := HttpRequest
    get:'http://news.bbcimg.co.uk/media/images/64001000/jpg/_64001280_63976026.jpg' asURI.
content:=req execute.
reader := JPEGImageReader new.
image := (reader from: content byteContents readStream) image

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