如何在异步回调

Question

捕捉局部变量的值我有这个for循环：

for(var i = 0; i < characters.length; i++) 
{ 
    var character = characters[i]; 
    charService.get(character.name).then(function (characterData) 
    { 
     //I want character to be captured here, i.e. the character in the current loop 
     character.data = characterData; 
    }); 
} 

由于charService.get()是异步的，由执行回调的时候，character是数组（最后一个元素，因为循环已经结束），因此以前的所有character都留在没有数据的情况下。

如何保证回调里面的character.data引用异步方法执行的循环的character？

Answer 1

使用Function.prototype.bind()尝试.then()功能，设置为character

for(var i = 0; i < characters.length; i++) 
{ 
    var character = characters[i]; 
    charService.get(character.name).then(function (characterData) 
    { 
     //I want character to be captured here, i.e. the character in the current loop 
     this.data = characterData; 
    }.bind(character)); 
} 

Answer 2

你可以把它包装成函数

for(var i = 0; i < characters.length; i++) 
{ 
    (function(character){ 
    charService.get(character.name).then(function (characterData) 
    { 
     //I want character to be captured here, i.e. the character in the current loop 
     character.data = characterData; 
    }); 
    })(characters[i]); 
}