Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)

目录

Activity -> Activity

Activity -> Fragment

Fragment -> Activity 

Activity -> Service


  • Activity -> Activity

      实现小例子:

         从MainActivity跳转并传值到Activity2,之后从Activity2再传值回到MainActivity

activity_main的布局:

 

activity2的布局:

 

    

    

MainActivity代码(写有备注):创建Bundle对象,向其里面加入需要传递的值,注意值的类型,添加完毕之后,由intent将该bundle对象传递即可。 

注意一下,如果另一个activity2返回来用的是setResult()函数,那么在MainActivity中传值是需要使用 startActivityForResult函数,如果单纯的使用startActivity函数进行跳转,会导致MainActivity中onActivityResult不会执行。

public class MainActivity extends AppCompatActivity implements View.OnClickListener {

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

        //获取控件
        Button button = findViewById(R.id.btn_send);
        textView = findViewById(R.id.textview_back);

        button.setOnClickListener(this);
    }

    //得到传回的数据
    @Override
    protected void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        switch (resultCode) {
            case 1:
                Bundle bundle_back=data.getExtras();
                String str=bundle_back.getString("b");
                textView.setText(str);
                break;
        }
    }

    //按钮点击事件
    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btn_send:
                Bundle bundle = new Bundle();
                bundle.putString("name","玛丽");
                bundle.putInt("age",15);

                Intent intent = new Intent(MainActivity.this,Activity2.class);
                intent.putExtras(bundle);
                startActivityForResult(intent,0);
            break;
        }
    }
}

Activity2代码:在获传递过来值的时候我一直获取为空值,感觉很奇怪,之后发现是有两点导致的

1.被传递到的这个Activity中对Intent的操作,不要写成 Intent intent = new Intent();,这样只是会重新在该页面创建了一个新的对象,而需要写成 Intent intent = getIntent();去获取前面传递的值。

2.对于获取需要传回的content的放置位置也很关键,不可以放在onCreate()函数里面获取,这样会导致只会在初始化的时候执行一次,之后写入数据后是不会再执行的,会导致传回去的值一直为空。

public class Activity2 extends Activity implements View.OnClickListener {
    String name,content;
    int age;
    EditText editText;
    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity2);

        //获取控件
        TextView textView = findViewById(R.id.text_receive);
        editText = findViewById(R.id.edit_back);
        Button button = findViewById(R.id.btn_back);

        //接收传来的值并显示
        Intent intent = getIntent();
        name = intent.getStringExtra("name");
        age = intent.getIntExtra("age",-1);

        textView.setText("名字:"+name+",年龄:"+age);



        button.setOnClickListener(this);
    }

    @Override
    public void onClick(View view) {
        switch (view.getId()){
            case R.id.btn_back:
                //返回值
                content = editText.getText().toString().trim();
                Intent intent_back = new Intent(Activity2.this,MainActivity.class);
                intent_back.putExtra("b",content);
                setResult(1,intent_back);
                finish();
            break;
        }
    }
}

执行效果如下:

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第1张图片 MainActivity初始页面

    

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第2张图片 点击传值后Activity2的界面,并传递给MainActivity  ok的作为回馈
Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第3张图片 点击按钮再次来到MainActivity页面,得到ok的反馈

  • Activity -> Fragment

 实现小例子:

       从Activity跳转并传值到Fragment

 activity_main的布局:




    

    

fragment_test的布局:




    

MainActivity代码(写有备注):注意需要将fragment与activity进行绑定

public class MainActivity extends AppCompatActivity {
    private EditText edit_input;
    private Button btn_send;
    private String inputContent;

    private FragmentManager manager;
    private FragmentTransaction transaction;

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

        //获取控件
        edit_input = findViewById(R.id.edit_input);
        btn_send = findViewById(R.id.btn_send);

        //fragment与activity进行绑定
        manager = getSupportFragmentManager();
        transaction = manager.beginTransaction();
        transaction.add(R.id.contentLayout, new FragmentTest());
        transaction.commit();

        //按钮点击事件
        btn_send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                inputContent = edit_input.getText().toString().trim();
                FragmentTest fragmentTest = new FragmentTest();
                Bundle bundle = new Bundle();
                bundle.putString("content", inputContent);
                fragmentTest.setArguments(bundle);
                manager = getSupportFragmentManager();
                transaction = manager.beginTransaction();
                transaction.replace(R.id.contentLayout, fragmentTest);
                transaction.commit();
            }
        });
    }
}

在从Activity -> Fragment传值中,困扰了我很久,我使用FragmentManager manager = getFragmentManager(); 再使用(transaction为FragmentTransaction的对象)

transaction.add(R.id.contentLayout, new FragmentTest()); 

该句下方会出现红线。最后成功解决使用的方法是FragmentManager manager =getSupportFragmentManager(); 上方导入的为

import androidx.fragment.app.FragmentManager;
import androidx.fragment.app.FragmentTransaction;

具体的原因目前我还是不太了解。

FragmentTest代码:

public class FragmentTest extends Fragment {
    private TextView tvContent;
    @Nullable
    @Override
    public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_test, null);

        tvContent = view.findViewById(R.id.tvContent);

        //获取activity传送过来的值
        Bundle bundle = getArguments();
        if (bundle != null) {
            tvContent.setText(bundle.getString("content"));
        }

        return view;
    }
}

运行结果如图:

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第4张图片

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第5张图片 点击发送后
  • Fragment -> Activity 

  activity_main的布局:




    

fragment_test的布局:




    

MainActivity代码(写有备注):

public class MainActivity extends Activity implements FragmentTest.CallBackValue {

    private TextView tv1;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        tv1 = (TextView) findViewById(R.id.tv1);

        //activity与fragment进行绑定
        FragmentManager manager = getFragmentManager();
        FragmentTransaction transaction = manager.beginTransaction();
        transaction.add(R.id.contents, new Fragmen1());
        transaction.commit();

    }
    //传递值
    @Override
    public void SendMessageValue(String content) {
        tv1.setText(content);
    }
}

FragmentTest代码:

public class FragmentTest extends Fragment{
    private Button btn1;
    private EditText et1;
    CallBackValue callBackValue;

    //fragment与activity产生关联是回调这个方法
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        callBackValue =(CallBackValue) getActivity();
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_layout1, container, false);

        //获取控件
        btn1 = (Button) view.findViewById(R.id.btn_send);
        et1 = (EditText) view.findViewById(R.id.edit_test);

        //点击事件
        btn1.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                String content = et1.getText().toString().trim();
                callBackValue.SendMessageValue(content);
            }
        });

        return view;
    }
    //定义一个回调接口
    public interface CallBackValue{
        public void SendMessageValue(String content);
    }
}

运行结果截图:

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第6张图片

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第7张图片 点击发送按钮后

  • Activity -> Service

  activity_main的布局如上。

方法一:使Activity实现implements ServiceConnection ,实现onServiceConnected函数。创ServiceTest.Binder的对象,通过这个对象来实现通信传值。

MainActivity代码(写有备注): 

public class MainActivity extends AppCompatActivity implements ServiceConnection {
    private EditText edit_input;
    private Button btn_send;
    private String inputContent;

    public ServiceTest.Binder binder = null;

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

        //获取控件
        edit_input = findViewById(R.id.edit_input);
        btn_send = findViewById(R.id.btn_send);

        //绑定服务
        Intent intent = new Intent(MainActivity.this,ServiceTest.class);
        bindService(intent,this, Context.BIND_AUTO_CREATE);

        //按钮点击事件
        btn_send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                inputContent = edit_input.getText().toString().trim();
                //通过 binder 对象来和 Service 进行通信
                if(binder != null)
                binder.sendData(inputContent);
            }
        });
    }

    @Override
    public void onServiceConnected(ComponentName componentName, IBinder iBinder) {
        binder = (ServiceTest.Binder)iBinder;
    }

    @Override
    public void onServiceDisconnected(ComponentName componentName) {

    }

    @Override
    protected void onDestroy() {
        super.onDestroy();
        unbindService(this);
    }
}

ServiceTest代码(写有备注): 

public class ServiceTest extends Service {

    String data;

    public ServiceTest(){

    }

    @Nullable
    @Override
    public IBinder onBind(Intent intent) {
        return new Binder();
    }

    public class Binder extends android.os.Binder{
        public void sendData(String data){
            ServiceTest.this.data = data;
            Toast.makeText(ServiceTest.this, "哈哈哈"+data, Toast.LENGTH_SHORT).show();
        }
    }
}

运行如下:

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第8张图片 点击发送按钮后

 方法二:使用Intent,适用于传送少量的数据。

MainActivity代码(写有备注): 

public class MainActivity extends AppCompatActivity {
    private EditText edit_input;
    private Button btn_send;
    private String inputContent;

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

        //获取控件
        edit_input = findViewById(R.id.edit_input);
        btn_send = findViewById(R.id.btn_send);

        //绑定服务
        Intent intent = new Intent(MainActivity.this,ServiceTest.class);

        //按钮点击事件
        btn_send.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                inputContent = edit_input.getText().toString().trim();
                intent.putExtra("test",inputContent);
                startService(intent);
            }
        });
    }
}

ServiceTest代码(写有备注): 

public class ServiceTest extends Service {

    String data;

    public ServiceTest(){

    }

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

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        //得到Activity传的数据
        data = intent.getStringExtra("test");
        Toast.makeText(ServiceTest.this, "传过来的数据"+data, Toast.LENGTH_SHORT).show();
        return super.onStartCommand(intent, flags, startId);

    }
}

运行截图:

Android中Activity各种页面跳转并传值(Activity -> Activity)(Activity -> Fragment)(Activity -> Service)_第9张图片 点击发送后

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