Dart、JavaScript 的一些代码啊啊啊啊啊～
投石击水，不起浪花，也泛涟漪。
Dart
Call 事件派发与监听
class Call {
Call._internal() {
// 构建单例，也可直接将 _callBackMap 变为静态成员，代码简洁，但是暴露了 _callBackMap。
}
static final Call _instance = Call._internal();
Map<String, List<Function>> _callBackMap = new Map<String, List<Function>>();
static bool hasCallBack(String eventKey, Function callback) {
if (_instance._callBackMap[eventKey] == null) {
return false;
}
return _instance._callBackMap[eventKey].contains(callback);
}
static void addCallBack(String eventKey, Function callback) {
if (_instance._callBackMap[eventKey] == null) {
_instance._callBackMap[eventKey] = [];
}
if (!hasCallBack(eventKey, callback)) {
_instance._callBackMap[eventKey].add(callback);
}
}
static void removeCallBack(String eventKey, Function callback) {
if (_instance._callBackMap[eventKey] == null) {
return;
}
_instance._callBackMap[eventKey].removeWhere((callBackFunc) => callBackFunc == callback);
}
static void dispatch(String eventKey, {var data}) {
if (_instance._callBackMap[eventKey] == null) {
throw Exception('未找到回调事件 $eventKey 的监听');
}
_instance._callBackMap[eventKey].forEach((callBackFunc) {
callBackFunc?.call(data);
});
}
}
/* ---------- */
void main() {
Call.addCallBack('test', (data) {
print('test1$data');
});
var test = (data) {
print('test2$data');
};
Call.addCallBack('test', test);
Call.dispatch('test', data: '123');
print('hasCallBack-test${Call.hasCallBack('test', test)}');
Call.removeCallBack('test', test);
Call.dispatch('test');
Call.dispatch('test-not');
}防抖
Function debounce(
Function func, [
int delay = 2000,
]) {
if (func == null) {
return () {
print('func is null');
};
}
Timer timer;
Function target = () {
if (timer?.isActive ?? false) {
timer?.cancel();
}
timer = Timer(Duration(milliseconds: delay), () {
func?.call();
});
};
return target;
}
/* ---------- */
void main() async {
print("Hello, World0!");
var test = debounce(() {
print("Hello, World1!");
}, 5000);
test();
await Future.delayed(Duration(milliseconds: 1000));
test();
await Future.delayed(Duration(milliseconds: 1000));
test();
print("Hello, World2!");
}
// 最后一次才有效，7s多打印一次 Hello, World1!。节流
Function throttle(
Function func, [
int delay = 2000,
]) {
if (func == null) {
return () {
print('func is null');
};
}
bool enable = true;
Function target = () async {
if (enable == true) {
enable = false;
func?.call();
await Future.delayed(Duration(milliseconds: delay));
enable = true;
}
};
return target;
}
/* ---------- */
void main() async {
print("Hello, World0!");
var test = throttle(() {
print("Hello, World1!");
}, 5000);
test();
await Future.delayed(Duration(milliseconds: 1000));
test();
await Future.delayed(Duration(milliseconds: 1000));
test();
print("Hello, World2!");
}
// 第一次才有效，严格意义立即打印一次 Hello, World1!。http-dao
Future fetch() async {
String getUrl = 'http://localhost:888';
final Map<String, String> header = {'Content-type': 'application/json', 'authorization': 'Bearer test'};
var response;
try {
response = await http.get(Uri.parse(getUrl), headers: header);
} catch (e) {
// ERROR
}
Utf8Decoder utf8decoder = Utf8Decoder();
var result = json.decode(utf8decoder.convert(response.bodyBytes));
if (response.statusCode == 200 || result['code'] == '0') {
// Success
} else {
// Failed
}
}Base64
String base64StrEncode(String sourceStr) {
List<int> bytes = utf8.encode(sourceStr);
String encodeStr = base64Encode(bytes);
return encodeStr;
}
String base64StrDecode(String encodedStr) {
List<int> bytes = base64Decode(encodedStr);
// String decodeStr = String.fromCharCodes(bytes);
String decodeStr = utf8.decode(bytes);
return decodeStr;
}JavaScript
Call 事件派发与监听
export default class Call {
private static instance: Call;
private constructor() { } // 不能初始化
/**
* 获取 Call 单例
* @returns
*/
static getInstance(): Call {
if (!this.instance) {
this.instance = new Call();
}
return this.instance;
}
private _callBackMap: { [key: string]: Function[] } = {};
static hasCallBack(eventKey: string, callBack: Function): boolean {
if (!Call.getInstance()._callBackMap[eventKey]) {
return false;
}
return Call.getInstance()._callBackMap[eventKey]?.includes(callBack) ?? false;
}
static addCallBack(eventKey: string, callback: Function): void {
if (!Call.getInstance()._callBackMap[eventKey]) {
Call.getInstance()._callBackMap[eventKey] = [];
}
if (!Call.hasCallBack(eventKey, callback)) {
Call.getInstance()._callBackMap[eventKey]?.push(callback);
}
}
static removeCallBack(eventKey: string, callback: Function): void {
if (!Call.getInstance()._callBackMap[eventKey]) {
return;
}
Call.getInstance()._callBackMap[eventKey] = Call.getInstance()._callBackMap[eventKey]?.filter((callBackFunc) => callBackFunc != callback);
}
static dispatch(eventKey: string, ...args: any) {
if (!Call.getInstance()._callBackMap[eventKey]) {
throw new Error(`未找到回调事件 ${eventKey} 的监听`);
}
Call.getInstance()._callBackMap[eventKey].forEach((callBackFunc) => {
callBackFunc?.apply(this, args);
});
}
}
/* ---------- */
Call.addCallBack('test', function () {
console.log('test1', arguments);
});
var test = function (data1, data2) {
console.log('test2', data1, data2);
};
Call.addCallBack('test', test);
Call.dispatch('test', 123, 456);
console.log(
'hasCallBack-test',
Call.hasCallBack('test', test),
Call.hasCallBack('test', () => {})
);
Call.removeCallBack('test', test);
Call.dispatch('test');
Call.dispatch('test-not');防抖
function debounce(fn, delay = 2000) {
let timer = null;
return function () {
clearTimeout(timer);
timer = setTimeout(function () {
fn.apply(this, arguments);
}, delay);
};
}
/* ---------- */
async function testFunc() {
console.time('x');
console.log('Hello, World0!');
var test = debounce(function () {
console.log('Hello, World1!');
console.timeEnd('x');
}, 5000);
test();
await new Promise((resolve) => {
setTimeout(() => resolve(), 1000);
});
test();
await new Promise((resolve) => {
setTimeout(() => resolve(), 1000);
});
test();
console.log('Hello, World2!');
}
testFunc();
// 最后一次才有效，7s多打印一次 Hello, World1!。节流
function throttle(fn, delay = 2000) {
let canRun = true;
return function () {
if (!canRun) return;
canRun = false;
fn.apply(this, arguments);
setTimeout(function () {
canRun = true;
}, delay);
};
}
/* ---------- */
async function testFunc() {
console.time('x');
console.log('Hello, World0!');
var test = throttle(function () {
console.log('Hello, World1!');
console.timeEnd('x');
}, 5000);
test();
await new Promise((resolve) => {
setTimeout(() => resolve(), 1000);
});
test();
await new Promise((resolve) => {
setTimeout(() => resolve(), 1000);
});
test();
console.log('Hello, World2!');
}
testFunc();
// 第一次才有效，严格意义立即打印一次 Hello, World1!。fetch/ajax/axios/XHR
/* ----- Ajax ----- */
$.ajax({
url: '/test',
success: function (result) {
console.log(result);
}
});
$.ajax({
url: '/test',
method: 'POST',
success: function (result) {
console.log(result);
}
});
$.ajax({
url: '/test',
data: { a: 10 },
success: function (result) {
console.log(result);
},
error: function (xhr, status, error) {
console.log(error);
}
});
$.ajax({
url: '/test',
headers: { contentType: 'application/json' },
method: 'POST',
data: JSON.stringify({ a: 10 }),
success: function (result) {
console.log(result);
}
});
$.get(url, data, callback); // querystring
$.post(url, data, callback); // x-www-form-urlencoded
/* ----- Fetch ----- */
fetch(url, {
headers: {
'content-type': 'application/x-www-form-urlencoded'
},
method: 'POST',
body: 'a=1&b=2&c[]=a&c[]=b'
})
.then((res) => res.json())
.then((data) => console.log(res))
.catch((e) => {});
fetch(url, {
headers: {
'content-type': 'application/json'
},
method: 'POST',
body: JSON.stringify({ a: 100 })
})
.then((res) => res.json())
.then((data) => console.log(res))
.catch((e) => {});
/* ----- Axios ----- */
axios({
url: 'http://localhost',
method: 'POST',
data: { a: 1 }
}).then((res) => console.log(res.data));
axios({
url: 'http://localhost',
method: 'POST',
headers: { 'Content-Type': 'application/x-www-form-urlencoded' },
data: 'a=1&b=2&c[]=a&c[]=b'
}).then((res) => console.log(res.data));
axios.post(url, data).then(callback);
/* ----- XHR-XMLHttpRequestAjax ----- */
function XMLHttpRequestAjax(method, url, callback, data, flag) {
var xhr;
flag = flag || true;
method = method.toUpperCase();
if (window.XMLHttpRequest) {
xhr = new XMLHttpRequest();
} else {
xhr = new ActiveXObject('Microsoft.XMLHttp');
}
xhr.onreadystatechange = function () {
if (xhr.readyState == 4 && xhr.status == 200) {
callback(xhr.responseText);
}
};
if (method == 'GET') {
var date = new Date(),
timer = date.getTime();
xhr.open('GET', url + '?' + data + '&timer' + timer, flag);
xhr.send();
} else if (method == 'POST') {
xhr.open('POST', url, flag);
xhr.setRequestHeader('Content-Type', 'application/x-www-form-urlencoded');
xhr.send(data);
}
}Base64
static base64Encode(str: string): string {
return Buffer.from(str, 'utf-8').toString('base64');
}
static base64Decode(str: string): string {
return Buffer.from(str, 'base64').toString('utf8');
}本文参与?腾讯云自媒体分享计划，分享自作者个人站点/博客。
原始发表：2021-04-15，如有侵权请联系 cloudcommunity@tencent.com 删除
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