Html 使用angularjs,如何对文本框执行数学运算,并在键入值时查看结果?
我有一个HTML文件,有两个文本框,一个用于值,另一个用于数量。底部的结果文本将值乘以数量并显示结果Html 使用angularjs,如何对文本框执行数学运算,并在键入值时查看结果?,html,angularjs,frontend,Html,Angularjs,Frontend,我有一个HTML文件,有两个文本框,一个用于值,另一个用于数量。底部的结果文本将值乘以数量并显示结果 <div ng-app="adder" ng-controller="addcontrol"> <table> <tr> <th>Value</th><th>Quantity</th> </tr> <
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
其目的是在屏幕上显示所有成对文本框行的总和。为此,我有一个“添加新”按钮,它不断添加额外的文本框对
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
HTML上出现的第一组文本框反映了包含属性“val”和“qty”的对象“numbers”数组的大小。相同的值绑定到文本框
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
但是,只有第一组值添加到屏幕上。当我不断添加新的文本框并输入新的值时,结果的值应该相应地改变,但事实并非如此
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
HTML代码
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
}))
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
我做错了什么?在您的代码中,总和的计算只执行一次
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
您需要添加作用域的监视或将函数绑定到ng change
事件,以便在更改数字时更新总和
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
例如,您可以执行以下操作:
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-change="update()" ng-model="number.val"></td>
<td><input type="text" ng-change="update()" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
控制器中的代码仅激活一次(渲染视图时)。因此,在您有机会添加任何行之前,您的总和只计算一次。您需要做的是将您的计算放入一个函数中,以便可以根据需要重复调用它
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
Tong的回答基本上是正确的,但我认为这是一个更好的方法:
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
<div ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{total()}}
</div>
定义一个total
函数,该函数在数组中循环并返回适当的总和。然后可以将该函数绑定到视图中的结果字段。这样做的好处是,您不必记住在任何可能导致总数更改的地方调用update()
(如文本框上的ng change
,以及deleteNumber
函数)。总数只是自动更新
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
这里有一个。除了问题之外,我知道这一点,但您可以在单个输入字段中执行任意算术运算:
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
{{$eval(表达式)}
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
根据派利努克斯的回答:这似乎很明显,但在这里。如果要添加2个表达式,请使用以下命令:
{{$eval(表达式1)+$eval(表达式2)}
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
Php
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
- id,数据类型为int,大小为11,自动递增并设置为主键
- Firstname,数据类型为varchar,大小为30
- Middlename,数据类型为varchar,大小为30
- Lastname,数据类型为varchar,大小为30
- 联系人,数据类型为int,大小为11
- 房屋地址,数据类型为int,大小为50
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>
Help TT是的,就复杂性而言,这将是一个更好的解决方案。我的答案基本上是尝试使用OP的逻辑。这三个例子的逻辑基本上是相同的。这只是在哪里以及如何触发计算的问题。
<div ng-app="adder" ng-controller="addcontrol">
<table>
<tr>
<th>Value</th><th>Quantity</th>
</tr>
<tr ng-repeat="number in numbers">
<td><input type="text" ng-model="number.val"></td>
<td><input type="text" ng-model="number.qty"></td>
<td><input type="button" ng-click="deleteNumber($index)" value= "Delete"></td>pp',[]);
</tr>
</table>
<input type="button" ng-click="add()" value="Add new">Result : {{sum}}
</div>
</body>
</html>