Dart-CheatSheet

Dart CheatSheet

dart-cheat-sheet

import 'dart:async';
import 'dart:math' show Random;
main() async {
print('Compute π using the Monte Carlo method.');
await for (var estimate in computePi().take(500)) {
print('π ≅ $estimate');
}
}
/// Generates a stream of increasingly accurate estimates of π.
Stream<double> computePi({int batch: 100000}) async* {
var total = 0;
var count = 0;
while (true) {
var points = generateRandom().take(batch);
var inside = points.where((p) => p.isInsideUnitCircle);
total += batch;
count += inside.length;
var ratio = count / total;
// Area of a circle is A = π⋅r², therefore π = A/r².
// So, when given random points with x ∈ <0,1>,
// y ∈ <0,1>, the ratio of those inside a unit circle
// should approach π / 4. Therefore, the value of π
// should be:
yield ratio * 4;
}
}
Iterable<Point> generateRandom([int seed]) sync* {
final random = Random(seed);
while (true) {
yield Point(random.nextDouble(), random.nextDouble());
}
}
class Point {
final double x, y;
const Point(this.x, this.y);
bool get isInsideUnitCircle => x * x + y * y <= 1;
}

Core

Async | 异步编程

HTML

Angular

BootStrap

Component | 组件

(
selector: '[tooltip]',
map: const {
'tooltip': '@text'
})
class Tooltip {
final Element element;
String text;
Tooltip(this.element) {
...
}
}
<span tooltip="Hello World!">...</span>

Module

class MyAppModule extends Module {
MyAppModule() {
install(new AnotherModule());
bind(TypeToBind);
bindByKey(KeyToBind);
}
}
main() {
applicationFactory()
.addModule(new MyAppModule())
.run();
}