Angular确实在HTML指令中提供了一些使用数字的for循环的支持:
<div data-ng-repeat="i in [1,2,3,4,5]">
do something
</div>
但是,如果作用域变量包含一个具有动态数字的范围,那么每次都需要创建一个空数组。
在控制器中
var range = [];
for(var i=0;i<total;i++) {
range.push(i);
}
$scope.range = range;
在HTML中
<div data-ng-repeat="i in range">
do something
</div>
这是可行的,但这是不必要的,因为我们在循环中根本不会使用范围数组。有人知道设置最小/最大值的范围或规则吗?
喜欢的东西:
<div data-ng-repeat="i in 1 .. 100">
do something
</div>
我提出了一个稍微不同的语法,它更适合我一点,并添加了一个可选的下界:
myApp.filter('makeRange', function() {
return function(input) {
var lowBound, highBound;
switch (input.length) {
case 1:
lowBound = 0;
highBound = parseInt(input[0]) - 1;
break;
case 2:
lowBound = parseInt(input[0]);
highBound = parseInt(input[1]);
break;
default:
return input;
}
var result = [];
for (var i = lowBound; i <= highBound; i++)
result.push(i);
return result;
};
});
你可以用哪个
<div ng-repeat="n in [10] | makeRange">Do something 0..9: {{n}}</div>
or
<div ng-repeat="n in [20, 29] | makeRange">Do something 20..29: {{n}}</div>
@Mormegil的解决方案的改进
app.filter('makeRange', function() {
return function(inp) {
var range = [+inp[1] && +inp[0] || 0, +inp[1] || +inp[0]];
var min = Math.min(range[0], range[1]);
var max = Math.max(range[0], range[1]);
var result = [];
for (var i = min; i <= max; i++) result.push(i);
if (range[0] > range[1]) result.reverse();
return result;
};
});
使用
<span ng-repeat="n in [3, -3] | makeRange" ng-bind="n"></span>
Three, two, one, zero, one, two, three
<span ng-repeat="n in [-3, 3] | makeRange" ng-bind="n"></span>
Minus 3, minus 2, minus 1, 0, 1, 2, 3
<span ng-repeat="n in [3] | makeRange" ng-bind="n"></span>
0, 1, 2, 3
<span ng-repeat="n in [-3] | makeRange" ng-bind="n"></span>
0-1-2-3