The application of the layer and its fixed position (3)

3, absolutely fixed position and relative fixed position


The character of the optional fixed position of the layer gives webpage architect brought very big convenience, but also brought certain trouble at the same time. Why to say so?

Everybody knows, to let a webpage can get used to the resolution that the user installs automatically, in the webpage the people in the process that make used the setting means of per cent, thereby all elements of the page anew composing, assure original format. But if you used a layer on the page, when you can discover when the browser size is changed, the position of the layer does not have a change however, result between it and other elements cooperated to appear amlposition phenomenon, the page becomes desultorily. And we are cannot enforce quite the user uses specific resolution, like thinking method lets the position of the layer also can resemble form only so according to the change of browser size new fixed position, this uses relative fixed position and absolutely fixed position reasonably with respect to need. Absolutely fixed position (Position:aBsolute) : Namely the orientation way with acquiescent layer, begin numerical value of computational fixed position at the brim of browser top left corner absolutely.
Relative fixed position (Position:rElative) : The positional photograph of the layer is installed to a certain element, this element position is changed, criterion the position of the layer is changed accordingly.

Contrast locates two kinds means, discover not hard, the layer that uses relative fixed position just is the way that realizes architect idea truly, master the composing of the layer completely thereby.

So, is absolutely fixed position used? Useful of course, the webpage that becomes you uses a layer to come entirely composing, and the page is the buy of house Zun Fang of use acquiesce, so the composing that the absolutely orientation way of use ac quiesce can go to the lavatory, improve the work efficiency of the design.

In Dreamweaver, although insertion layer is those who use is absolutely (Absolute) orientation way, but insertion kind is different, brought result is different. We had known in front, the layer that use menu inserts is the coordinate that did not locate, procrastinate when your use mouse only after moving this to change its position, ability can keep coordinate cost. And dilatory the initiative position coordinate of the layer that come out is the coordinate when the mouse begins an action.

Make clear a concept please: Gift by Dreanweaver the layer that coordinate is worth is the layer that locates at browser brim absolutely. The layer that does not bring coordinate value is the layer that locates at some element relatively!

So, the simplest setting locates relatively of the layer means is: The position that make choice of inserts a layer (for example a certain unit case or the somewhere in the page) keep cursor in this position, choose Insert next- - > Layer, the layer of a fixed size can be founded in this position, this layer is opposite locate at this position. Need attention, use the layer that this kind of means founds, you can use a mouse to adjust its volume only, can not move absolutely its position! That is to say, on attribute face plate, in the positional column of the layer (Left Top) can not have numerical value absolutely.

Below a lot of circumstances, the position of insertion layer is not certain and exact, especially Dreamweaver is not right place to see namely the software of earning, the composing of the webpage shows in the browser ability can see the show of composing truly only, the method that place of place above face says gives an issue too simple and easily with respect to what show. This moment, you need what the layer locates to consult content, let it accomplish relative fixed position truly.


Consult simply content can be layer of a father, insert the blank layer of a relative fixed position first namely, the layer that you need truly is inserted in the layer here, and this layer is OK of position of optional and dilatory change. But inserted a blank layer more in the webpage after all so, what the webpage stylist that I think to it is not major certainly hopes. We introduce use CSS to realize the layer of real relative fixed position below.
 

We need to install a CSS Class first, the means that will define fixed position is opposite:
.ceng {Position:&Nbsp;relative; }
Next, gift what you need consult content (can be Table, tr, td. . .  ) attribute of a CSS is this kind. Such browsers can be origin with its top left corner, building new coordinate is. Consult in this again of content inferior insert a layer, criterion the layer consults at this absolutely content fixed position, if you need to change the po sition of the layer, you are OK and direct the numerical value that inputs Left Top on the attribute face plate of the layer (can not use a mouse dilatory) , be sure to keep in mind this numeric coordinate origin is the consulting that you appoint content, the brim that is not a browser (when the editor in Dreamweaver, this look as if locate at page brim absolutely, but in the browser, it is absolutely consult at what what you appoint of content) .
 

Use layer of a lot of friends is for when dynamic effect, use time line to let motion of a certain object rise for example, increase a webpage move feeling, can the layer after so relative fixed position still move? The answer is affirmative of course. Because define two positions of the object to need to procrastinate,move this object to change the position, the method that uses simple layer fixed position so is no good, but if you use CSS to install the effect of relative fixed position, can come true completely so. Just need to notice, when the initiative position that defines motion and end position, you still can not use a mouse dilatory, and the numerical value that can input Left and Top by oneself only.

The use of original layer is not very complex, but I regard as it alone however paragraphic, the reason has certain difficulty with respect to the fixed position that is a layer, after hope friends had seen the introduction of ab ove, much in Dreamweaver experimentation a few, appear easily still otherwise of the problem.

OK! Say so much about the use of the layer.