Home > Developer > JavaScript

Js implementation method similar to Sina Weibo's homepage content for gradual display

Source: Internet
Author: User
Developer on Alibaba Coud: Build your first app with APIs, SDKs, and tutorials on the Alibaba Cloud. Read more ＞

Js implementation method similar to Sina Weibo's homepage content for gradual display

Key Aspect 1:

1

2

3

4

5

If (list_li.length> = 1 ){

List. insertBefore (li, list_li [0]);

} Else {

List. appendChild (li );

}

Insert new content from the front. If there is no new content, insert new content to the back.

Key Aspect 2:

1

2

Var height = li. offsetHeight;

Li. style. height = '0 ';

Obtain the li height, and then set the li height to 0, because the height changes from 0 to the existing height.

Key Aspect 3:

1

2

3

Startrun (li, "height", height, function (){

Startrun (li, "opacity", "100 ");

})

First, high change, then transparency change

Finally, run the following code:

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

43

44

45

46

47

48

49

50

51

52

53

54

55

56

57

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

<! DOCTYPE html>

<Html>

<Head>

<Meta charset = "gb2312"/>

<Title> untitled document </title>

<Style>

<! --

Body, ul, li {margin: 0; padding: 0; font: 12px/1.5 arial ;}

# List {width: 400px; margin: 10px auto ;}

# List li {list-style: none; padding: 5px 0;

Overflow: hidden; border-bottom: 1px dotted # ccc;

Filter: alpha (opacity: 0); opacity: 0; vertical-align: middle ;}

-->

</Style>

<Script>

<! --

Window. onload = function (){

Var btn = document. getElementById ("btn ");

Var con = document. getElementById ("con ");

Var list = document. getElementById ("list ");

Var list_li = list. getElementsByTagName ("li ");

Btn. onclick = function (){

Var li = document. createElement ("li ");

Li. innerHTML = con. value;

Con. value = '';

If (list_li.length> = 1 ){

List. insertBefore (li, list_li [0]);

} Else {

List. appendChild (li );

}

Var height = li. offsetHeight;

Li. style. height = '0 ';

Startrun (li, "height", height, function (){

Startrun (li, "opacity", "100 ");

})

}

}

Function getstyle (obj, name ){

If (obj. currentStyle ){

Return obj. currentStyle [name];

} Else {

Return getComputedStyle (obj, false) [name];

}

}

Function startrun (obj, attr, target, fn ){

ClearInterval (obj. timer );

Obj. timer = setInterval (function (){

Var cur = 0;

If (attr = "opacity "){

Cur = Math. round (parseFloat (getstyle (obj, attr) * 100 );

} Else {

Cur = parseInt (getstyle (obj, attr ));

}

Var speed = (target-cur)/8;

Speed = speed> 0? Math. ceil (speed): Math. floor (speed );

If (cur = target ){

ClearInterval (obj. timer );

If (fn ){

Fn ();

}

} Else {

If (attr = "opacity "){

Obj. style. filter = "alpha (opacity =" + (cur + speed) + ")";

Obj. style. opacity = (cur + speed)/100;

} Else {

Obj. style [attr] = cur + speed + "px ";

}

}

}, 30)

}

// -->

</Script>

</Head>

<Body>

<Textarea id = "con" cols = "50" rows = "5"> </textarea>

<Input id = "btn" name = "" type = "button" value = "publish">

<Ul id = "list">

</Ul>

</Body>

</Html>

This article is an English version of an article which is originally in the Chinese language on aliyun.com and is provided for information purposes only. This website makes no representation or warranty of any kind, either expressed or implied, as to the accuracy, completeness ownership or reliability of the article or any translations thereof. If you have any concerns or complaints relating to the article, please send an email, providing a detailed description of the concern or complaint, to info-contact@alibabacloud.com. A staff member will contact you within 5 working days. Once verified, infringing content will be removed immediately.

Contact Us

The content source of this page is from Internet, which doesn't represent Alibaba Cloud's opinion; products and services mentioned on that page don't have any relationship with Alibaba Cloud. If the content of the page makes you feel confusing, please write us an email, we will handle the problem within 5 days after receiving your email.

If you find any instances of plagiarism from the community, please send an email to: info-contact@alibabacloud.com and provide relevant evidence. A staff member will contact you within 5 working days.

A Free Trial That Lets You Build Big!

Start building with 50+ products and up to 12 months usage for Elastic Compute Service

Get Started for Free

  • Sales Support

    1 on 1 presale consultation

    Chat Contact Sales

  • After-Sales Support

    24/7 Technical Support 6 Free Tickets per Quarter Faster Response

    Open a Ticket

  • Alibaba Cloud offers highly flexible support services tailored to meet your exact needs.

    Learn More