我正在尝试从一个“活动”发送客户类的对象,并在另一个“”中显示它。

客户类别的代码:

public class Customer {

    private String firstName, lastName, address;
    int age;

    public Customer(String fname, String lname, int age, String address) {

        firstName = fname;
        lastName = lname;
        age = age;
        address = address;
    }

    public String printValues() {

        String data = null;

        data = "First Name :" + firstName + " Last Name :" + lastName
        + " Age : " + age + " Address : " + address;

        return data;
    }
}

我想将其对象从一个“活动”发送到另一个“,然后在另一个活动”上显示数据。

我怎样才能做到这一点?


当前回答

像这样创建自定义类:

public class Test implements Parcelable {
    String message;

    protected Test(Parcel in) {
        message = in.readString();
    }

    public static final Creator<Test> CREATOR = new Creator<Test>() {
        @Override
        public Test createFromParcel(Parcel in) {
            return new Test(in);
        }

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

    public String getMessage() {
        return message;
    }

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

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

使用Intent发送数据,如下所示:开始活动之前,必须设置一些数据

Intent intent = new Intent(context, PostDetailsActivity.class);
                intent.putExtra("data", (Parcelable) test);
                ((context)).startActivity(intent);

从以下意图中获取数据:

Test test = (Test) getIntent().getParcelableExtra("data");

其他回答

你可以尝试使用该类。限制是它不能在一个过程之外使用。

一项活动:

 final Object obj1 = new Object();
 final Intent in = new Intent();
 in.putExtra(EXTRA_TEST, new Sharable(obj1));

其他活动:

final Sharable s = in.getExtras().getParcelable(EXTRA_TEST);
final Object obj2 = s.obj();

public final class Sharable implements Parcelable {

    private Object mObject;

    public static final Parcelable.Creator < Sharable > CREATOR = new Parcelable.Creator < Sharable > () {
        public Sharable createFromParcel(Parcel in ) {
            return new Sharable( in );
        }


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

    public Sharable(final Object obj) {
        mObject = obj;
    }

    public Sharable(Parcel in ) {
        readFromParcel( in );
    }

    Object obj() {
        return mObject;
    }


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


    @Override
    public void writeToParcel(final Parcel out, int flags) {
        final long val = SystemClock.elapsedRealtime();
        out.writeLong(val);
        put(val, mObject);
    }

    private void readFromParcel(final Parcel in ) {
        final long val = in .readLong();
        mObject = get(val);
    }

    /////

    private static final HashMap < Long, Object > sSharableMap = new HashMap < Long, Object > (3);

    synchronized private static void put(long key, final Object obj) {
        sSharableMap.put(key, obj);
    }

    synchronized private static Object get(long key) {
        return sSharableMap.remove(key);
    }
}

我以前用Paceable或Serializable设置对象以进行传输,但每当我向对象(模型)添加其他变量时,我都必须将其全部注册。太不方便了。

在活动或片段之间传输对象非常容易。

Android数据缓存

public class MyClass implements Serializable{
    Here is your instance variable
}

现在要在startActivity中传递该类的对象。只需使用此选项:

Bundle b = new Bundle();
b.putSerializable("name", myClassObject);
intent.putExtras(b);

这在这里有效,因为MyClass实现了Serializable。

不可能序列化任何类型的对象。例如,不能序列化携带代码而不是数据的委托方法或接口。因此,我编写了一个“Box”类,您可以使用它来传递任何类型的数据,而无需序列化。

1-将数据用于预期用途:

Intent I = new Intent(this, YourActivity.class);
CustomClass Date = new CustomClass();
Box.Add(I, "Name", Data);

2-用于从意向检索数据:

CustomClass Data = Box.Get(getIntent(), "Name");

3-要在使用后删除数据,请将此方法添加到活动中:

@Override
protected void onDestroy() {
    Box.Remove(getIntent());
    super.onDestroy();
}

4-并将此代码添加到项目中:

package ir.namirasoft.Utility;

import android.content.Intent;

import java.util.HashMap;
import java.util.Vector;

public class Box {
    // Number
    private static int Number = 1;

    public static int NextNumber() {
        return Number++;
    }

    //
    private static String _Intent_Identifier = "_Intent_Identifier";
    private static HashMap<Integer, Vector<Integer>> DeleteList = new HashMap<Integer, Vector<Integer>>();
    private static HashMap<Integer, HashMap<String, Object>> ObjectList = new HashMap<Integer, HashMap<String, Object>>();

    public static int GetIntent_Identifier(Intent I) {
        int Intent_Identifier = I.getIntExtra(_Intent_Identifier, 0);
        if (Intent_Identifier == 0)
            I.putExtra(_Intent_Identifier, Intent_Identifier = NextNumber());
        return Intent_Identifier;
    }

    public static void Add(Intent I, String Name, Object O) {
        int Intent_Identifier = GetIntent_Identifier(I);
        synchronized (ObjectList) {
            if (!ObjectList.containsKey(Intent_Identifier))
                ObjectList.put(Intent_Identifier, new HashMap<String, Object>());
            ObjectList.get(Intent_Identifier).put(Name, O);
        }
    }

    public static <T> T Get(Intent I, String Name) {
        int Intent_Identifier = GetIntent_Identifier(I);
        synchronized (DeleteList) {
            DeleteList.remove(Intent_Identifier);
        }
        return (T) ObjectList.get(Intent_Identifier).get(Name);
    }

    public static void Remove(final Intent I) {
        final int Intent_Identifier = GetIntent_Identifier(I);
        final int ThreadID = NextNumber();
        synchronized (DeleteList) {
            if (!DeleteList.containsKey(Intent_Identifier))
                DeleteList.put(Intent_Identifier, new Vector<Integer>());
            DeleteList.get(Intent_Identifier).add(ThreadID);
        }
        new Thread(new Runnable() {
            @Override
            public void run() {
                try {
                    Thread.sleep(60 * 1000);
                } catch (InterruptedException e) {
                }
                synchronized (DeleteList) {
                    if (DeleteList.containsKey(Intent_Identifier))
                        if (DeleteList.get(Intent_Identifier).contains(ThreadID))
                            synchronized (ObjectList) {
                                ObjectList.remove(Intent_Identifier);
                            }
                }
            }
        }).start();
    }
}

**Box类是线程安全的。

从此活动启动另一个活动,并通过捆绑对象传递参数

Intent intent = new Intent(getBaseContext(), YourActivity.class);
intent.putExtra("USER_NAME", "xyz@gmail.com");
startActivity(intent);

检索其他活动的数据(YourActivity)

String s = getIntent().getStringExtra("USER_NAME");

这对于一种简单的数据类型是可以的。但是如果你想在活动之间传递复杂的数据。你需要先序列化它。

这里有员工模型

class Employee{
    private String empId;
    private int age;
    print Double salary;
    
    getters...
    setters...
}

您可以使用google提供的Gson-lib来序列化复杂的数据这样地

String strEmp = new Gson().toJson(emp);
Intent intent = new Intent(getBaseContext(), YourActivity.class);
intent.putExtra("EMP", strEmp);
startActivity(intent);

Bundle bundle = getIntent().getExtras();
String empStr = bundle.getString("EMP");
            Gson gson = new Gson();
            Type type = new TypeToken<Employee>() {
            }.getType();
            Employee selectedEmp = gson.fromJson(empStr, type);