android studio AIDL使用方法。

最近学习aidl，在as上遇到了问题，老是出现问题，这里总结一下aidl的用法。

因为例子中需要使用自定义类型作为传入参数，所以这篇文章基于此背景写的。

step one:
在你的src/main目录下新建一个aidl的文件夹，然后在aidl文件夹中新建一个包，注意，这的包名要完全等同于androidMainfest里面的包名，然后我们在其中初始化我们自定义的类型(Book)，Book.aidl是Book类在AIDL中的生命，IBookManager是我们定义的一个接口。
结构如下：

step two:
我们需要在gradle里面添加如下的语句：

 sourceSets {
        main {
            manifest.srcFile 'src/main/AndroidManifest.xml'
            java.srcDirs = ['src/main/java', 'src/main/aidl']
            resources.srcDirs = ['src/main/java', 'src/main/aidl']
            aidl.srcDirs = ['src/main/aidl']
            res.srcDirs = ['src/main/res']
            assets.srcDirs = ['src/main/assets']
        }
    }

因为aidl文件我们初始化后，如果没有告诉as自定类型在哪里，它自己根本找不到，(这个白痴，让我弄了好久,吐槽一下)。

step three:
重新Build一下project就可以了，就有相关的信息出现在bulid/generated/source/aidl/debug里面了
如下：

最后生成的效果如下：

/*
 * This file is auto-generated.  DO NOT MODIFY.
 * Original file: /Users/linchen/Desktop/MyApplication/app/src/main/aidl/com/mytest/adiltest/BookManager.aidl
 */
package com.mytest.adiltest;

public interface BookManager extends android.os.IInterface {
    /**
     * Local-side IPC implementation stub class.
     */
    public static abstract class Stub extends android.os.Binder implements com.mytest.adiltest.BookManager {
        private static final java.lang.String DESCRIPTOR = "com.mytest.adiltest.BookManager";

        /**
         * Construct the stub at attach it to the interface.
         */
        public Stub() {
            this.attachInterface(this, DESCRIPTOR);
        }

        /**
         * Cast an IBinder object into an com.mytest.adiltest.BookManager interface,
         * generating a proxy if needed.
         */
        public static com.mytest.adiltest.BookManager asInterface(android.os.IBinder obj) {
            if ((obj == null)) {
                return null;
            }
            android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
            if (((iin != null) && (iin instanceof com.mytest.adiltest.BookManager))) {
                return ((com.mytest.adiltest.BookManager) iin);
            }
            return new com.mytest.adiltest.BookManager.Stub.Proxy(obj);
        }

        @Override
        public android.os.IBinder asBinder() {
            return this;
        }

        @Override
        public boolean onTransact(int code, android.os.Parcel data, android.os.Parcel reply, int flags) throws android.os.RemoteException {
            switch (code) {
                case INTERFACE_TRANSACTION: {
                    reply.writeString(DESCRIPTOR);
                    return true;
                }
                case TRANSACTION_getBookList: {
                    data.enforceInterface(DESCRIPTOR);
                    java.util.List<com.mytest.adiltest.Book> _result = this.getBookList();
                    reply.writeNoException();
                    reply.writeTypedList(_result);
                    return true;
                }
                case TRANSACTION_addBook: {
                    data.enforceInterface(DESCRIPTOR);
                    com.mytest.adiltest.Book _arg0;
                    if ((0 != data.readInt())) {
                        _arg0 = com.mytest.adiltest.Book.CREATOR.createFromParcel(data);
                    } else {
                        _arg0 = null;
                    }
                    this.addBook(_arg0);
                    reply.writeNoException();
                    return true;
                }
            }
            return super.onTransact(code, data, reply, flags);
        }

        private static class Proxy implements com.mytest.adiltest.BookManager {
            private android.os.IBinder mRemote;

            Proxy(android.os.IBinder remote) {
                mRemote = remote;
            }

            @Override
            public android.os.IBinder asBinder() {
                return mRemote;
            }

            public java.lang.String getInterfaceDescriptor() {
                return DESCRIPTOR;
            }

            @Override
            public java.util.List<com.mytest.adiltest.Book> getBookList() throws android.os.RemoteException {
                android.os.Parcel _data = android.os.Parcel.obtain();
                android.os.Parcel _reply = android.os.Parcel.obtain();
                java.util.List<com.mytest.adiltest.Book> _result;
                try {
                    _data.writeInterfaceToken(DESCRIPTOR);
                    mRemote.transact(Stub.TRANSACTION_getBookList, _data, _reply, 0);
                    _reply.readException();
                    _result = _reply.createTypedArrayList(com.mytest.adiltest.Book.CREATOR);
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
                return _result;
            }

            @Override
            public void addBook(com.mytest.adiltest.Book book) throws android.os.RemoteException {
                android.os.Parcel _data = android.os.Parcel.obtain();
                android.os.Parcel _reply = android.os.Parcel.obtain();
                try {
                    _data.writeInterfaceToken(DESCRIPTOR);
                    if ((book != null)) {
                        _data.writeInt(1);
                        book.writeToParcel(_data, 0);
                    } else {
                        _data.writeInt(0);
                    }
                    mRemote.transact(Stub.TRANSACTION_addBook, _data, _reply, 0);
                    _reply.readException();
                } finally {
                    _reply.recycle();
                    _data.recycle();
                }
            }
        }

        static final int TRANSACTION_getBookList = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
        static final int TRANSACTION_addBook = (android.os.IBinder.FIRST_CALL_TRANSACTION + 1);
    }

    public java.util.List<com.mytest.adiltest.Book> getBookList() throws android.os.RemoteException;

    public void addBook(com.mytest.adiltest.Book book) throws android.os.RemoteException;
}

参考文章：
http://www.android100.org/html/201507/15/165012.html
http://blog.youkuaiyun.com/wuyuxing24/article/details/46948961