android 跨进程 ContentProvider android 跨进程启动app

转载

mob64ca140a8e67 2023-11-29 16:21:49

文章标签 android User ide 文章分类 Android 移动开发

Android系统中，各应用程序都运行在自己的进程里，进程之间一般无法直接进行数据交换。为了实现这种跨进程通信（interprocess communication, IPC），Android提供了AIDL（Android Interface Definition Language，android接口定义语言） Service。

要使用AIDL进行通信，需要以下步骤：

服务端

1.定义AIDL接口。通常在该接口中定义业务方法。该接口文件以.aidl结尾。

2.使用platform-tools/aidl.exe工具将AIDL接口文件生成Stub。该Stub继承自android.os.Binder类。在ADT开发环境下会自动生成Stub在gen目录下。

3.自定义一个Binder类，继承自Stub，并且实现在AIDL接口中定义的业务方法。

4.定义一个service，在 onBind(Intent intent)方法中返回自定义的Binder对象。

5.在Androidmanifest.xml中注册该service。

注：AIDL接口文件中用到的数据类型，除了基本类型、String、List、Map以及CharSequence外，其他类型都需要导包，即使在同一包下。

客户端

1.将服务端的AIDL等相关文件拷贝到客户端。

2.绑定服务，并且在ServiceConnection.onServiceConnected(ComponentName name, IBinder service)方法中调用Stub.asInterface(service)方法返回一个AIDL接口，通过该接口就可以调用业务方法了。

下面通过一个例子来说明如何使用AIDL实现跨进程通信。

服务端

定义AIDL接口文件UserService.aidl：

package com.zzj.ui2.serviceAidlDemo;

import com.zzj.ui2.serviceAidlDemo.User;
import com.zzj.ui2.serviceAidlDemo.Book;

interface UserService{
	List<Book> getBooks(in User user);
}

Adt环境下会在gen目录下自动生成接口UserService.java，该接口包含一个Stub内部类：

/*
 * This file is auto-generated.  DO NOT MODIFY.
 * Original file: E:\\androidWorkspace\\zzj-android-demo2\\src\\com\\zzj\\ui2\\serviceAidlDemo\\UserService.aidl
 */
package com.zzj.ui2.serviceAidlDemo;
public interface UserService extends android.os.IInterface
{
/** Local-side IPC implementation stub class. */
public static abstract class Stub extends android.os.Binder implements com.zzj.ui2.serviceAidlDemo.UserService
{
private static final java.lang.String DESCRIPTOR = "com.zzj.ui2.serviceAidlDemo.UserService";
/** Construct the stub at attach it to the interface. */
public Stub()
{
this.attachInterface(this, DESCRIPTOR);
}
/**
 * Cast an IBinder object into an com.zzj.ui2.serviceAidlDemo.UserService interface,
 * generating a proxy if needed.
 */
public static com.zzj.ui2.serviceAidlDemo.UserService asInterface(android.os.IBinder obj)
{
if ((obj==null)) {
return null;
}
android.os.IInterface iin = obj.queryLocalInterface(DESCRIPTOR);
if (((iin!=null)&&(iin instanceof com.zzj.ui2.serviceAidlDemo.UserService))) {
return ((com.zzj.ui2.serviceAidlDemo.UserService)iin);
}
return new com.zzj.ui2.serviceAidlDemo.UserService.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_getBooks:
{
data.enforceInterface(DESCRIPTOR);
com.zzj.ui2.serviceAidlDemo.User _arg0;
if ((0!=data.readInt())) {
_arg0 = com.zzj.ui2.serviceAidlDemo.User.CREATOR.createFromParcel(data);
}
else {
_arg0 = null;
}
java.util.List<com.zzj.ui2.serviceAidlDemo.Book> _result = this.getBooks(_arg0);
reply.writeNoException();
reply.writeTypedList(_result);
return true;
}
}
return super.onTransact(code, data, reply, flags);
}
private static class Proxy implements com.zzj.ui2.serviceAidlDemo.UserService
{
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.zzj.ui2.serviceAidlDemo.Book> getBooks(com.zzj.ui2.serviceAidlDemo.User user) throws android.os.RemoteException
{
android.os.Parcel _data = android.os.Parcel.obtain();
android.os.Parcel _reply = android.os.Parcel.obtain();
java.util.List<com.zzj.ui2.serviceAidlDemo.Book> _result;
try {
_data.writeInterfaceToken(DESCRIPTOR);
if ((user!=null)) {
_data.writeInt(1);
user.writeToParcel(_data, 0);
}
else {
_data.writeInt(0);
}
mRemote.transact(Stub.TRANSACTION_getBooks, _data, _reply, 0);
_reply.readException();
_result = _reply.createTypedArrayList(com.zzj.ui2.serviceAidlDemo.Book.CREATOR);
}
finally {
_reply.recycle();
_data.recycle();
}
return _result;
}
}
static final int TRANSACTION_getBooks = (android.os.IBinder.FIRST_CALL_TRANSACTION + 0);
}
public java.util.List<com.zzj.ui2.serviceAidlDemo.Book> getBooks(com.zzj.ui2.serviceAidlDemo.User user) throws android.os.RemoteException;
}

Book类：

package com.zzj.ui2.serviceAidlDemo;

import android.os.Parcel;
import android.os.Parcelable;

public class Book implements Parcelable {
	public static final Creator<Book> CREATOR = new Creator<Book>() {

		@Override
		public Book[] newArray(int size) {
			return new Book[size];
		}

		@Override
		public Book createFromParcel(Parcel source) {
			Book book = new Book();
			book.setName(source.readString());
			book.setPrice(source.readDouble());
			return book;
		}
	};
	private String name;
	private double price;

	public String getName() {
		return name;
	}

	public void setName(String name) {
		this.name = name;
	}

	public double getPrice() {
		return price;
	}

	public void setPrice(double price) {
		this.price = price;
	}

	@Override
	public int describeContents() {
		return 0;
	}

	@Override
	public void writeToParcel(Parcel dest, int flags) {
		dest.writeString(name);
		dest.writeDouble(price);
	}

}

User类：

package com.zzj.ui2.serviceAidlDemo;

import android.os.Parcel;
import android.os.Parcelable;

public class User implements Parcelable {
	public static final Creator<User> CREATOR = new Creator<User>() {

		@Override
		public User createFromParcel(Parcel source) {
			User user = new User();
			user.setUsername(source.readString());
			user.setPassword(source.readString());
			return user;
		}

		@Override
		public User[] newArray(int size) {
			return new User[size];
		}
	};

	private String username;
	private String password;

	public String getUsername() {
		return username;
	}

	public void setUsername(String username) {
		this.username = username;
	}

	public String getPassword() {
		return password;
	}

	public void setPassword(String password) {
		this.password = password;
	}

	@Override
	public int describeContents() {
		return 0;
	}

	@Override
	public void writeToParcel(Parcel dest, int flags) {
		dest.writeString(username);
		dest.writeString(password);
	}

}

自定义的类型如果需要被AIDL接口引用，必须在相应的AIDL文件中声明。

Book.aidl：

package com.zzj.ui2.serviceAidlDemo;
parcelable Book;

User.aidl：

package com.zzj.ui2.serviceAidlDemo;
parcelable User;

自定义的类型需要实现Parcelable接，服务端通过writeToParcel(Parcel dest, int flags)方法实现序列化；然后定义了一个静态的Creator成员变量，客户端通过createFromParcel(Parcel source)方法实现反序列化。

定义一个service：

package com.zzj.ui2.serviceAidlDemo;

import java.util.ArrayList;
import java.util.List;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteException;

import com.zzj.ui2.serviceAidlDemo.UserService.Stub;

public class AidlService extends Service {

	private IBinder binder = new Mybinder();

	@Override
	public IBinder onBind(Intent intent) {
		return binder;
	}

	private class Mybinder extends Stub {

		@Override
		public List<Book> getBooks(User user) throws RemoteException {
			List<Book> books = new ArrayList<Book>();
			if (user == null) {
				return books;
			}
			if ("001".equals(user.getUsername())
					&& "123".equals(user.getPassword())) {

				Book book = new Book();
				book.setName("时间简史");
				book.setPrice(30.5d);
				books.add(book);

				book = new Book();
				book.setName("失控");
				book.setPrice(50.5d);
				books.add(book);
			}
			return books;
		}
	}

}

在服务端的Androidmanifest.xml中注册该service：

<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.zzj.ui2"
    android:versionCode="1"
    android:versionName="1.0" >

    <uses-sdk
        android:minSdkVersion="8"
        android:targetSdkVersion="18" />

    <!-- 声明外部调用本应用service所需的权限 -->
    <permission android:name="com.zzj.AIDL_SERVICE" />

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >

        <!-- 1.com.zzj.ui2.serviceAidlDemo -->
        <service
            android:name="com.zzj.ui2.serviceAidlDemo.AidlService"
            android:permission="com.zzj.AIDL_SERVICE" >
            <intent-filter>
                <action android:name="com.zzj.ui2.AIDL_SERVICE" />
            </intent-filter>
        </service>
    </application>

</manifest>

将服务端部署到设备上。至此服务端开发完毕。

客户端

将UserService.aidl、Book.java、User.java、Book.aidl、User.aidl等文件从服务端拷贝到客户端。注意：客户端的包名要与服务端的包名一致。

在Activity中绑定远程service：

package com.zzj.ui.serviceAidlDemo;

import java.util.List;

import android.app.Activity;
import android.content.ComponentName;
import android.content.Context;
import android.content.Intent;
import android.content.ServiceConnection;
import android.os.Bundle;
import android.os.IBinder;
import android.os.RemoteException;
import android.view.View;
import android.widget.EditText;
import android.widget.Toast;

import com.zzj.ui.R;
import com.zzj.ui2.serviceAidlDemo.Book;
import com.zzj.ui2.serviceAidlDemo.User;
import com.zzj.ui2.serviceAidlDemo.UserService;
import com.zzj.ui2.serviceAidlDemo.UserService.Stub;

public class MainActivity extends Activity {
	private UserService userService;
	private AidlServiceConnection serviceConnection;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.serviceaidl_activity);

		// 绑定服务
		Intent service = new Intent();
		service.setAction("com.zzj.ui2.AIDL_SERVICE");
		serviceConnection = new AidlServiceConnection();
		bindService(service, serviceConnection, Context.BIND_AUTO_CREATE);
	}

	public void getBooks(View v) {
		User user = new User();
		user.setUsername(((EditText) findViewById(R.id.username_edt)).getText()
				.toString());
		user.setPassword(((EditText) findViewById(R.id.password_edt)).getText()
				.toString());
		try {
			List<Book> books = userService.getBooks(user);
			if (books == null || books.isEmpty()) {
				Toast.makeText(this, "该用户没有订书或者用户名或密码错误！", Toast.LENGTH_LONG)
						.show();
			} else {
				StringBuilder sb = new StringBuilder();
				sb.append("查询成功！\r\n");
				for (Book book : books) {
					sb.append(book.getName() + " --> " + book.getPrice()
							+ "\r\n");
				}
				Toast.makeText(this, sb.toString(), Toast.LENGTH_LONG).show();
			}
		} catch (RemoteException e) {
			e.printStackTrace();
			Toast.makeText(this, "查询出错！", Toast.LENGTH_LONG).show();
		}
	}

	private class AidlServiceConnection implements ServiceConnection {

		@Override
		public void onServiceConnected(ComponentName name, IBinder service) {
			userService = Stub.asInterface(service);
		}

		@Override
		public void onServiceDisconnected(ComponentName name) {
			userService = null;
		}

	}

	@Override
	protected void onDestroy() {
		super.onDestroy();
		// 解绑服务
		unbindService(serviceConnection);
	}
}

Activity布局文件：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical" >

    <EditText
        android:id="@+id/username_edt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="帐号" >
    </EditText>

    <EditText
        android:id="@+id/password_edt"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:inputType="textPassword"
        android:ems="10"
        android:hint="密码" />

    <Button
        android:id="@+id/getBooks_btn"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:onClick="getBooks"
        android:text="getbooks" />

</LinearLayout>

在Androidmanifest.xml中申请调用service的权限：

<!-- 调用aidl service权限 -->
    <uses-permission android:name="com.zzj.AIDL_SERVICE" />

测试效果：

android 跨进程 ContentProvider android 跨进程启动app_User

本文章为转载内容，我们尊重原作者对文章享有的著作权。如有内容错误或侵权问题，欢迎原作者联系我们进行内容更正或删除文章。

上一篇：python barra 风控限制智能风控 python

下一篇：python代码写自己名字教程如何用python写出自己的名字

提问和评论都可以，用心的回复会被更多人看到评论

发布评论

相关文章

官方博客	全部文章	热门标签	班级博客
了解我们	网站地图	意见反馈

鸿蒙开发者社区	51CTO学堂
51CTO	软考资讯

android 跨进程 ContentProvider android 跨进程启动app

android 跨进程 ContentProvider android 跨进程启动app

服务端

客户端

51CTO博客