How to open pictures on php mobile phone without displaying pictures

How to open pictures without displaying pictures on PHP mobile phones

Nowadays, mobile phones have become an indispensable electronic device in our lives. Browsers on mobile phones are becoming more and more popular. In addition to being used for surfing the Internet, browsers on mobile phones can also be used to view various files and information, such as pictures. However, when developing web pages using PHP, you sometimes encounter a problem, that is, the images cannot be displayed when the web page is opened on a mobile phone. So, what exactly causes this problem? Is there any way to solve this problem?

There are two main reasons for this problem. On the one hand, it is because the image path used is incorrect, and on the other hand, it is because the image format used is incompatible. But no matter what the reason is, it can be solved by the following methods.

1. Use relative paths instead of absolute paths

When you use absolute paths, you may encounter the problem that pictures cannot be displayed when you open them on your mobile phone. This is because paths have different syntax on different devices. Relative paths do not have this problem because they specify the location of the image relative to the directory where the current web page is located. Therefore, relative paths can be resolved correctly by different devices, even on devices using different operating systems or browsers.

For example, suppose your website directory structure is:

/var/www/html
└── images
    ├── image1.jpg
    └── subfolder
        └── image2.jpg

If you want to use image1.jpg and image2.jpg on your php page, what should you do?

• If you use relative paths in "/var/www/html/index.php", you can use "images/image1.jpg" to reference image1.jpg, use "images/subfolder/image2 .jpg" to reference image2.jpg.
• If you use relative paths in "/var/www/html/subfolder/index.php", you can use "../images/image1.jpg" to reference image1.jpg and "image2.jpg" ” to reference image2.jpg.

Remember that relative paths are environment-independent, so it works on all operating systems and browsers.

2. Be careful with slashes

In PHP, the slash (/) is not a path separator in many cases, but is used as a division operator. Therefore, when using paths in PHP, you need to use specific functions to generate the paths. We can use "DIRECTORY_SEPARATOR" instead of slashes and we can avoid this problem.

For example, assuming your website directory structure is:

/var/www/html
└── images
    ├── image1.jpg
    └── subfolder
        └── image2.jpg

Then, we can use this code to generate the path:

$path = "/ var / www / html / images / image1.jpg";
$path = str_replace ('/', DIRECTORY_SEPARATOR, $path);

This ensures that the correct one is used in the path path separator so that this path can be correctly parsed by all operating systems.

3. Incompatible image formats

Another common problem is incompatible image formats. Some formats of images cannot be displayed properly on some browsers or operating systems. Therefore, we need to choose the image format carefully.

When we develop a PHP website, it is best to use common formats, such as JPEG, PNG, etc., which are well supported on most devices. However, if you are using unconventional formats such as WEBP or AVIF, you may encounter problems with images not displaying correctly on certain devices.

If you must use unusually formatted images, it is recommended to add an alternative to the code. For example, if you use images in the WEBP format, you can add a PNG image as an alternative. When the device cannot load the WEBP image, the PNG image will be automatically loaded.

4. Cache Cleaning

Finally, if you encounter the problem of being unable to display images, you can try clearing the browser cache. Due to the browser cache, sometimes even if the file path or file format is correct, the image still cannot be displayed properly. If it still cannot be displayed normally after clearing the cache, it may be caused by other factors, and you need to further find out the cause.

In general, the problem of not displaying images when opening images in PHP requires us to pay attention to path selection, be careful about the use of slashes, choose image formats with good compatibility and clear browser cache. This way we can display the image correctly in PHP.

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