如何在Android中传递大型数据?


此示例演示如何在Android中活动之间传递大型数据

步骤1 - 在Android Studio中创建一个新项目,转到文件 ⇒ 新建项目,并填写所有必需的详细信息以创建新项目。

步骤2 - 将以下代码添加到res/layout/activity_main.xml。

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   xmlns:tools = "http://schemas.android.com/tools"
   android:layout_width = "match_parent"
   android:layout_height = "match_parent"
   android:layout_margin = "16dp"
   android:orientation = "vertical"
   tools:context = ".MainActivity">
   <EditText
      android:id = "@+id/etName"
      android:layout_width = "match_parent"
      android:layout_height = "wrap_content"
      android:layout_gravity = "center"
      android:hint = "Name"
      android:inputType = "textCapWords" />
   <EditText
      android:id = "@+id/etAge"
      android:layout_width = "match_parent"
      android:layout_height = "wrap_content"
      android:layout_gravity = "center"
      android:hint = "Age"
      android:inputType = "number" />
   <EditText
      android:id = "@+id/etCity"
      android:layout_width = "match_parent"
      android:layout_height = "wrap_content"
      android:layout_gravity = "center"
      android:hint = "City"
      android:inputType = "textCapWords" />
   <Button
      android:id = "@+id/button"
      android:layout_width = "match_parent"
      android:layout_height = "wrap_content"
      android:layout_gravity = "center"
      android:layout_marginTop = "16dp"
      android:text = "Next" />
</LinearLayout>

步骤3 - 将以下代码添加到src/User.java

package com.example.myapplication;
import java.io.Serializable;
public class User implements Serializable {
   private String city;
   private String name;
   private String age;
   User(String name, String age, String city) {
      super();
      this.name = name;
      this.age = age;
      this.city = city;
   }
   public String getCity() {
      return city;
   }
   public void setCity(String city) {
      this.city = city;
   }
   public String getName() {
      return name;
   }
   public void setName(String name) {
      this.name = name;
   }
   public String getAge() {
      return age;
   }
   public void setAge(String age) {
      this.age = age;
   }
}

步骤4 - 将以下代码添加到src/MainActivity.java

package com.example.myapplication;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {
   EditText etName, etAge, etCity;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_main);
      etName = findViewById(R.id.etName);
      etAge = findViewById(R.id.etAge);
      etCity = findViewById(R.id.etCity);
      Button button = findViewById(R.id.button);
      button.setOnClickListener(new View.OnClickListener() {
         @Override
         public void onClick(View v) {
            String name = etName.getText().toString().trim();
            String age = etAge.getText().toString().trim();
            String city = etCity.getText().toString().trim();
            ArrayList<User> userList = new ArrayList<>();
            userList.add(new User(name, age, city));
            Bundle bundle = new Bundle();
            bundle.putSerializable("myUser", userList);
            Intent intent = new Intent(MainActivity.this, SecondActivity.class);
            intent.putExtras(bundle);
            startActivity(intent);
         }
      });
   }
}

步骤5 - 将以下代码添加到res/layout/activity_second.xml。

<?xml version = "1.0" encoding = "utf-8"?>
<LinearLayout xmlns:android = "http://schemas.android.com/apk/res/android"
   xmlns:tools = "http://schemas.android.com/tools"
   android:layout_width = "match_parent"
   android:layout_height = "match_parent"
   android:layout_margin = "16dp"
   android:orientation = "vertical"
   tools:context = ".SecondActivity">
   <TextView
      android:id = "@+id/textView"
      android:layout_width = "match_parent"
      android:layout_height = "wrap_content" />
</LinearLayout>

步骤6 - 将以下代码添加到src/SecondActivity.java

package com.example.myapplication;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.widget.TextView;
import java.util.ArrayList;

public class SecondActivity extends AppCompatActivity {
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.activity_second);
      Bundle bundle = getIntent().getExtras();
      if (bundle ! = null) {
         ArrayList<User> userList = (ArrayList<User>) bundle.getSerializable("myUser");
         if (userList ! = null) {
            String name = userList.get(0).getName();
            String age = userList.get(0).getAge();
            String city = userList.get(0).getCity();
            TextView tvName = findViewById(R.id.textView);
            String user = "Name: " + name + "
Age: " + age + "
City: " + city;             tvName.setText(user);          }       }    } }

步骤7 - 将以下代码添加到androidManifest.xml

<?xml version = "1.0" encoding = "utf-8"?>
<manifest xmlns:android = "http://schemas.android.com/apk/res/android"
   package = "com.example.myapplication">
   <application
      android:allowBackup = "true"
      android:icon = "@mipmap/ic_launcher"
      android:label = "@string/app_name"
      android:roundIcon = "@mipmap/ic_launcher_round"
      android:supportsRtl = "true"
      android:theme = "@style/AppTheme">
      <activity android:name = ".MainActivity">
         <intent-filter>
            <action android:name = "android.intent.action.MAIN" />
            <category android:name = "android.intent.category.LAUNCHER" />
         </intent-filter>
      </activity>
      <activity android:name = ".SecondActivity"></activity>
   </application>
</manifest>

让我们尝试运行您的应用程序。我假设您已将您的实际Android移动设备连接到您的计算机。要从Android Studio运行应用程序,请打开您的一个项目活动文件,然后单击运行  工具栏中的图标。选择您的移动设备作为选项,然后检查您的移动设备,它将显示您的默认屏幕 -

点击这里下载项目代码

更新于:2019年7月30日

888 次浏览

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