我试图理解ng-if和ng-show/ng-hide之间的区别,但对我来说它们看起来是一样的。
在选择使用一种或另一种时,我应该记住有什么区别吗?
我试图理解ng-if和ng-show/ng-hide之间的区别,但对我来说它们看起来是一样的。
在选择使用一种或另一种时,我应该记住有什么区别吗?
当前回答
@Gajus Kuizinas and @CodeHater are correct. Here i am just giving an example. While we are working with ng-if, if the assigned value is false then the whole html elements will be removed from DOM. and if assigned value is true, then the html elements will be visible on the DOM. And the scope will be different compared to the parent scope. But in case of ng-show, it wil just show and hide the elements based on the assigned value. But it always stays in the DOM. Only the visibility changes as per the assigned value.
http://plnkr.co/edit/3G0V9ivUzzc8kpLb1OQn?p=preview
希望这个例子能帮助你理解范围。 尝试给ng-show和ng-if赋假值,并在控制台中检查DOM。 尝试在输入框中输入值并观察差异。
<!DOCTYPE html>
你好砰砰作响!
<input type="text" ng-model="data">
<div ng-show="true">
<br/>ng-show=true :: <br/><input type="text" ng-model="data">
</div>
<div ng-if="true">
<br/>ng-if=true :: <br/><input type="text" ng-model="data">
</div>
{{data}}
其他回答
Ng-show和ng-hide的工作方式相反。但是ng-hide或ng-show与ng-if的区别是,如果我们使用ng-if,那么元素将在dom中创建,而使用ng-hide/ng-show,元素将完全隐藏。
ng-show=true/ng-hide=false:
Element will be displayed
ng-show=false/ng-hide=true:
element will be hidden
ng-if =true
element will be created
ng-if= false
element will be created in the dom.
ng-if if false will remove elements from DOM. This means that all your events, directives attached to those elements will be lost. For example, ng-click to one of child elements, when ng-if evaluates to false, that element will be removed from DOM and again when it is true it is recreated. ng-show/ng-hide does not remove the elements from DOM. It uses CSS styles (.ng-hide) to hide/show elements .This way your events, directives that were attached to children will not be lost. ng-if creates a child scope while ng-show/ng-hide does not.
请注意,现在发生在我身上的一件事: Ng-show通过css隐藏内容,是的,但它导致了奇怪的小故障在div的应该是按钮。
我有一个底部有两个按钮的卡,根据实际状态,一个与第三个交换,示例编辑按钮与新条目。使用ng-show=false来隐藏左边的按钮(首先出现在文件中),下面的按钮的右边框出现在卡片外面。 Ng-if通过完全不包括代码来修复这个问题。 (只是在这里检查是否有一些隐藏的惊喜使用ng-if而不是ng-show)
@Gajus Kuizinas and @CodeHater are correct. Here i am just giving an example. While we are working with ng-if, if the assigned value is false then the whole html elements will be removed from DOM. and if assigned value is true, then the html elements will be visible on the DOM. And the scope will be different compared to the parent scope. But in case of ng-show, it wil just show and hide the elements based on the assigned value. But it always stays in the DOM. Only the visibility changes as per the assigned value.
http://plnkr.co/edit/3G0V9ivUzzc8kpLb1OQn?p=preview
希望这个例子能帮助你理解范围。 尝试给ng-show和ng-if赋假值,并在控制台中检查DOM。 尝试在输入框中输入值并观察差异。
<!DOCTYPE html>
你好砰砰作响!
<input type="text" ng-model="data">
<div ng-show="true">
<br/>ng-show=true :: <br/><input type="text" ng-model="data">
</div>
<div ng-if="true">
<br/>ng-if=true :: <br/><input type="text" ng-model="data">
</div>
{{data}}
ng-if和ng-show的一个有趣的区别是:
安全
如果ng-if块中的DOM元素值为false,则不会被呈现
在ng-show的情况下,用户可以打开检查元素窗口并将其值设置为TRUE。
随着一声巨响,原本要隐藏的全部内容都显示出来了,这是一个安全漏洞。:)