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JQuery callbacks.lock()用法及代碼示例


用法 
callbacks.lock() => Callbacks

說明：將回調列表鎖定在當前狀態。

  • 添加的版本：1.7callbacks.lock()

    • 此方法不接受任何參數。

此方法返回它所附加的回調對象 (this)。

如果創建回調對象時使用"memory" 標誌作為其參數，則可能會在回調列表鎖定後添加和觸發其他函數。

例子：

使用 callbacks.lock() 鎖定回調列表，以避免對列表狀態進行進一步更改：

// A sample logging function to be added to a callbacks list
var foo = function( value ) {
  console.log( "foo:" + value );
};
 
var callbacks = $.Callbacks();
 
// Add the logging function to the callback list
callbacks.add( foo );
 
// Fire the items on the list, passing an argument
callbacks.fire( "hello" );
// Outputs "foo: hello"
 
// Lock the callbacks list
callbacks.lock();
 
// Try firing the items again
callbacks.fire( "world" );
 
// As the list was locked, no items were called,
// so "world" isn't logged

使用 callbacks.lock() 鎖定帶有 "memory," 的回調列表，然後繼續使用該列表：

<!doctype html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>callbacks.lock demo</title>
  <script src="https://code.jquery.com/jquery-3.5.0.js"></script>
</head>
<body>
 
<div id="log"></div>
 
<script>
// Simple function for logging results
var log = function( value ) {
  $( "#log" ).append( "<p>" + value + "</p>" );
};
 
// Two sample functions to be added to a callbacks list
var foo = function( value ) {
  log( "foo: " + value );
};
var bar = function( value ) {
  log( "bar: " + value );
};
 
// Create the callbacks object with the "memory" flag
var callbacks = $.Callbacks( "memory" );
 
// Add the foo logging function to the callback list
callbacks.add( foo );
 
// Fire the items on the list, passing an argument
callbacks.fire( "hello" );
// Outputs "foo: hello"
 
// Lock the callbacks list
callbacks.lock();
 
// Try firing the items again
callbacks.fire( "world" );
// As the list was locked, no items were called,
// so "foo: world" isn't logged
 
// Add the foo function to the callback list again
callbacks.add( foo );
 
// Try firing the items again
callbacks.fire( "silentArgument" );
// Outputs "foo: hello" because the argument value was stored in memory
 
// Add the bar function to the callback list
callbacks.add( bar );
 
callbacks.fire( "youHadMeAtHello" );
// Outputs "bar: hello" because the list is still locked,
// and the argument value is still stored in memory
</script>
 
</body>
</html>

演示：

相關用法


注：本文由純淨天空篩選整理自jquery.com大神的英文原創作品 callbacks.lock()。非經特殊聲明，原始代碼版權歸原作者所有，本譯文未經允許或授權，請勿轉載或複製。