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如何在flex中重构大括号内的代码

actionscript flex

1

airportyh · 技术社区 · 16 年前

Data binding in ActionScript 真的很酷。但是,如果我想将一个大开关或大括号内的if语句重构为一个函数,例如:

{person.gender == 'male' ? 'Mr.' : 'Ms.'}

进入:

{salutation(person)}

编译器不允许我这样做。我知道属性,我可以在Person对象上编写getter和setter。但是因为我现在使用的是内联JSON对象,所以这不方便(我想)。重构此代码的其他好方法是什么?

回答马特的评论。人的数据类型只是普通的对象。它是从来自服务调用的JSON格式解码的。

1 回复 | 直到 16 年前

1

4

Christophe Herreman 16 年前

您需要使Person类(假设您有一个)可绑定,这样才能工作。

但是,既然您说您使用的是JSON对象,那么我假设您只有从JSON字符串解析的匿名对象。如果是那样的话,我很确定这不会奏效。您需要创建一个具有可绑定属性的强类型对象。

仅供参考:为了避免为要创建的每个对象编写自定义JSON解析器,可以使用bytearray技巧从普通对象创建强类型对象:

public static function toInstance( object:Object, clazz:Class ):* {
  var bytes:ByteArray = new ByteArray();
  bytes.objectEncoding = ObjectEncoding.AMF0;

  // Find the objects and byetArray.writeObject them, adding in the
  // class configuration variable name -- essentially, we're constructing
  // and AMF packet here that contains the class information so that
  // we can simplly byteArray.readObject the sucker for the translation

  // Write out the bytes of the original object
  var objBytes:ByteArray = new ByteArray();
  objBytes.objectEncoding = ObjectEncoding.AMF0;
  objBytes.writeObject( object );

  // Register all of the classes so they can be decoded via AMF
  var typeInfo:XML = describeType( clazz );
  var fullyQualifiedName:String = typeInfo.@name.toString().replace( /::/, "." );
  registerClassAlias( fullyQualifiedName, clazz );

  // Write the new object information starting with the class information
  var len:int = fullyQualifiedName.length;
  bytes.writeByte( 0x10 );  // 0x10 is AMF0 for "typed object (class instance)"
  bytes.writeUTF( fullyQualifiedName );
  // After the class name is set up, write the rest of the object
  bytes.writeBytes( objBytes, 1 );

  // Read in the object with the class property added and return that
  bytes.position = 0;

  // This generates some ReferenceErrors of the object being passed in
  // has properties that aren't in the class instance, and generates TypeErrors
  // when property values cannot be converted to correct values (such as false
  // being the value, when it needs to be a Date instead).  However, these
  // errors are not thrown at runtime (and only appear in trace ouput when
  // debugging), so a try/catch block isn't necessary.  I'm not sure if this
  // classifies as a bug or not... but I wanted to explain why if you debug
  // you might seem some TypeError or ReferenceError items appear.
  var result:* = bytes.readObject();
  return result;
}