Javascript obtains and determines the height, width, etc. of the browser window, screen, web page, etc. _javascript skills

HTML precise positioning attributes: scrollLeft, scrollWidth, clientWidth, offsetWidth

scrollHeight: Get the scroll height of the object.
scrollLeft: Sets or gets the distance between the left edge of the object and the leftmost end of the currently visible content in the window
scrollTop: Sets or gets the distance between the topmost edge of the object and the topmost end of the visible content in the window
scrollWidth: Get the scroll width of the object
offsetHeight: Get the height of the object relative to the layout or the parent coordinate specified by the offsetParent property
offsetLeft: Get the height of the object relative to the layout or the parent coordinate specified by the offsetParent property Calculate the left position
offsetTop: Get the calculated top position of the object relative to the layout or the parent coordinate specified by the offsetTop attribute
event.clientX The horizontal coordinate relative to the document
event.clientY The vertical coordinate relative to the document
event.offsetX is the horizontal coordinate relative to the container
event.offsetY is the vertical coordinate relative to the container
document.documentElement.scrollTop is the value of vertical scrolling
event.clientX document.documentElement.scrollTop is relative to the horizontal position of the document The amount of coordinate scrolling in the vertical direction
The difference between IE and FireFox is as follows:
IE6.0, FF1.06:

Copy code The code is as follows:

clientWidth = width padding
clientHeight = height padding
offsetWidth = width padding border
offsetHeight = height padding border
IE5.0/5.5:
clientWidth = width – border
clientHeight = height – border
offsetWidth = width
offsetHeight = height

Tip: The margin attribute in CSS has nothing to do with clientWidth, offsetWidth, clientHeight, and offsetHeight

The width of the visible area of ​​the web page: document.body.clientWidth
The height of the visible area of ​​the web page: document. body.clientHeight
The width of the visible area of ​​the web page: document.body.offsetWidth (including the width of the side lines)
The height of the visible area of ​​the web page: document.body.offsetHeight (including the height of the side lines)
The width of the full text of the web page: document .body.scrollWidth
The height of the full text of the web page: document.body.scrollHeight
The height of the web page being scrolled: document.body.scrollTop
The left side of the web page being scrolled: document.body.scrollLeft
The main part of the web page: window.screenTop
The left part of the main part of the web page: window.screenLeft
The height of the screen resolution: window.screen.height
The width of the screen resolution: window.screen.width
Screen available work area height: window.screen.availHeight
Screen available work area width: window.screen.availWidth

Technical Points

The code in this section mainly uses some properties of the Document object regarding the window. The main functions and usage of these properties are as follows.
To get the size of the window, different properties and methods need to be used for different browsers: to detect the real size of the window, you need to use the properties of the Window under Netscape; under IE you need to go deep inside the Document to perform the body Detection; in the DOM environment, if you want to get the size of the window, you need to pay attention to the size of the root element, not the element.
The innerWidth property of the Window object contains the inner width of the current window. The innerHeight property of the Window object contains the inner height of the current window.
The body attribute of the Document object corresponds to the tag of the HTML document. The documentElement property of the Document object represents the root node of the HTML document.
document.body.clientHeight represents the current height of the window where the HTML document is located. document.body.clientWidth represents the current width of the window where the HTML document is located.

Sample code

Copy code The code is as follows:

🎜 >                                                                                                                              >                                                            The actual size of the browser window-->
The actual height of the browser window:

Actual width of the browser window:
>                                                                                                                                                                                                                                    () //Function: get size
                                                                                                                                                                                                                                                                                           since cument.body.clientWidth)) winWidth = document .body.clientWidth;
                                                                                                                                                                                                                                                                                        ​winHeight= document.body.clientHeight;
//Detect the body by going deep into the Document and get the window size
if (document.documentElement && document.documentElement.clientHeight && document.documentElement.clientWidth) {
winHeight = document.documentElement.clientHeight;
winWidth = document.documentElement.clientWidth;
}
//The results are output to two text boxes
document.form1.availHeight.value = winHeight;
document .form1.availWidth.value = winWidth;
                                
                     findDimensions();





Source program interpretation

(1) The program first creates a form containing two text boxes to display the current width and height of the window, and their values ​​will change as the window size changes. (2) In the subsequent JavaScript code, two variables winWidth and winHeight are first defined to save the height and width values ​​of the window. (3) Then, in the function findDimensions (), use window.innerHeight and window.innerWidth to get the height and width of the window, and save them in the two aforementioned variables.

(4) Then detect the body by going deep inside the Document, obtain the window size, and store it in the two variables mentioned above.

(5) At the end of the function, by accessing the form elements by name, the results are output to two text boxes.
(6) At the end of the JavaScript code, complete the entire operation by calling the findDimensions () function.