UIWebView和iPhone 4视网膜显示屏 [英] UIWebView and iPhone 4 retina display

问题描述

我有一个 UIWebView ，它会显示一些本地文本和图像。我在某个地方犯了错误，或者 UIWebView 没有自动处理高分辨率的 @ 2x 后缀图片。

I have a UIWebView which displays some local text and images. Either I've made a mistake somewhere, or the UIWebView doesn't automatically handle the @2x suffix for high resolution images.

所以，我的问题是还有其他人成功将 @ 2x 图片加载到 UIWebView 通过正常的方式，还是我需要做一些特别的事情？我可以以某种方式检测我的用户是否有视网膜显示器吗？

So, my question is has anyone else successfully loaded @2x images into a UIWebView through the normal means, or do I need to do something special? Can I somehow detect if my user has a retina display?

推荐答案

根据您的要求......

As per your request...

测试功能。如果你想知道你是否需要显示视网膜图像或常规图像，那么测试你的设备是否有视网膜显示器，而不是特定型号的显示器（未来证明你的应用程序尽你所能，意味着你必须改变当一个新模型出来时，更少的东西）。为此，您可以使用以下示例代码：

Test for functionality. If you want to know if you need to display a retina image or a regular image, then test if your device has a retina display, not that it's of a particular model (future proof your application as best you can, means you have to change less stuff when a new model comes out). To do this, you can use the following sample code:

if([[UIScreen mainScreen] respondsToSelector:@selector(scale)] &&
   [[UIScreen mainScreen] scale] == 2.0)
{
    /* We have a retina display. */
}
else
{
    /* We do not. */
}

这段代码是安全的，截至我写这篇文章的时候，所有型号和所有固件版本。它在将来的版本中也是安全的，直到Apple弃用 scale 方法，这可能永远不会发生。

This code is safe, as of the time I wrote this, on all models and on all firmware versions. It will be safe on future versions as well until Apple deprecates the scale method, which may never happen.

更多在你的问题上，我不知道如何在webview中做到这一点，而没有预先设置视网膜图像和非视网膜图像的位置。一旦我有了这些信息，我（过去）用它来替换网页希望我替换的一些已知的标记文本，就像在HTML中说的那样： { {{image_location}}} 在哪里我可以下载HTML数据，将其转换为字符串格式，然后替换该字符串替换该文本，如果我们是@ 2x图像的URL在视网膜显示器上，使用适当的比例因子，或者如果没有，则使用正常大小的图像（使用上面的代码）。

More on your question, I don't know how to do that in a webview without having the locations to a retina image and a non-retina image beforehand. Once I have that info, I have (in the past) used it to replace some known sentinel text that the web page expected me to replace, as in I would put something in the HTML that had say: {{{image_location}}} where I could download the HTML data, get it into string format, then do a replace on that string replacing that text, with the URL of the @2x image if we're on a retina display, with the appropriate scale factor, or the normal sized image if not (using the above code).

希望如果没有人能更好的话，这会有所帮助解决方案。

Hope this helps if nobody comes along with a better solution.

这篇关于UIWebView和iPhone 4视网膜显示屏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！