js implements uploading images and previewing images before uploading_javascript skills

Upload the image and preview the image to get an idea of ​​what the image will look like after uploading. This function is implemented with js, and then called in the change event of the fileupload control, so that after the image is selected using fileupload, the image will be automatically displayed. . The function is very simple, but very practical.

js code for preview image:

Copy code The code is as follows:

fileupload control and image used to preview images:

Copy code The code is as follows:

< /asp:FileUpload>

The function is very simple and the code is also very easy to understand. I believe everyone can understand it without me having to talk nonsense. I feel like there’s really not much to say in writing an article like this, so I won’t say much and let’s focus on the code.