AndroidJNIHelper.GetFieldID 获取域 ID

# [AndroidJNIHelper](AndroidJNIHelper.html).GetFieldID 获取域 ID

static function *GetFieldID* (*javaClass* : IntPtr,
*fieldName* : string, *signature* : string = "", *isStatic*
: bool = false) : IntPtr

### Parameters**参数**

* *javaClass*
  Raw JNI Java class object (obtained by calling [AndroidJNI.FindClass](../AndroidJNI/AndroidJNI.FindClass.html)).
  
  原始 JNI Java 类对象。（通过调用 [AndroidJNI.FindClass](../AndroidJNI/AndroidJNI.FindClass.html)）
* *fieldName*
  Name of the field as declared in Java.
* *signature*
  Field signature (e.g. obtained by calling [AndroidJNIHelper.GetSignature](AndroidJNIHelper.GetSignature.html)).
  
  域签名（例如通过调用 [AndroidJNIHelper.GetSignature](AndroidJNIHelper.GetSignature.html)）。
* *isStatic*
  Set to true for static methods; false for instance
  (nonstatic) methods.
  设置为 true 为静态方法；false 为实例（非静态）方法。

*Description* 描述

Scans a particular Java class for a field matching a name and a
signature.

扫描一个特定的 Java 类，用于一个域匹配一个名字和一个签名。

The signature comparison is done to allow sub-/base-classes of a class types.
If no signature is provided the first field with the correct name will be
returned.

签名比较是为了允许类的类型的 sub-/base-classes。如果没有提供签名，具有正确的名称的首个域将被返回。

参见：[AndroidJNIHelper.GetSignature](AndroidJNIHelper.GetSignature.html), [AndroidJNIHelper.GetConstructorID](AndroidJNIHelper.GetConstructorID.html),
[AndroidJNIHelper.GetMethodID](AndroidJNIHelper.GetMethodID.html)