activity与fragment之间的传递数据

Posted 2020-09-26 QinXiao.Shou

 

首先activity之间的数据传递就是

用intent和intent+bundle

intent

传递

Intent i= new Intent(MainActivity.this,TheAty.class);
             i.putExtra("date","Hello SWWWWWW");
             startActivity(i);

接受数据

 Intent i =getIntent();

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

　　　　　　//通过“date”关键字进行添加tv.setText(i.getStringExtra("date"));

 

 

intent+bundle

传递数据

   Intent i= new Intent(MainActivity.this,TheAty.class);
                Bundle b=new Bundle();
                b.putString("name","SWWWWW");
                b.putInt("age",21);
                b.putString("depart","KuaiJi");
                i.putExtras(b);
               startActivity(i);

接受数据

 Intent i =getIntent();
        Bundle data=i.getExtras();
        tv=(TextView) findViewById(R.id.tv);
       tv.setText(String.format("name=%s,age=%d,depart=%s",data.getString("name"),data.getInt("age"),data.getString("depart")));

 

下面就是Activity与fragment之间的传递数据

activity传给fragment

第一种

MyFragment myFragment = new MyFragment();
        Bundle bundle = new Bundle();
        bundle.putString("DATA",values);//这里的values就是我们要传的值
        myFragment.setArguments(bundle);

第二种

//宿主activity中的getTitles()方法
public String getTitles(){
    return "hello";
}

//Fragment中的onAttach方法
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        titles = ((MainActivity) activity).getTitles();
    }
//通过强转成宿主activity，就可以获取到传递过来的数据

 

3 这个回调方法，在很多api中经常使用，我就看了一天api我就知道这种回调经常使用而且非常有用

Fragment向activity中传值

1.在Fragment中写一个回调接口  

2.在activity中实现这个回调接口

3，在Fragment中onAttach 方法中得到activity中实现好的 实例化接口对象

4，用接口的对象  进行传值

activity

package com.qianfeng.fragmenttoactivity;  
  
import com.qianfeng.fragmenttoactivity.Fragmen1.CallBackValue;  
  
import android.os.Bundle;  
import android.annotation.SuppressLint;  
import android.app.Activity;  
import android.app.FragmentManager;  
import android.app.FragmentTransaction;  
import android.view.Menu;  
import android.widget.TextView;  
  
@SuppressLint("NewApi")   
public class MainActivity extends Activity implements CallBackValue{  
  
    private TextView tv1;  
    @Override  
    protected void onCreate(Bundle savedInstanceState) {  
        super.onCreate(savedInstanceState);  
        setContentView(R.layout.activity_main);  
          
        tv1 = (TextView) findViewById(R.id.tv1);  
          
        FragmentManager manager = getFragmentManager();  
        FragmentTransaction transaction = manager.beginTransaction();  
          
        transaction.add(R.id.contents, new Fragmen1());  
        transaction.commit();  
          
    }  
    //要获取的值  就是这个参数的值  
    @Override  
    public void SendMessageValue(String strValue) {  
        // TODO Auto-generated method stub  
        tv1.setText(strValue);  
    }  
  
  
      
}  

Frag

@SuppressLint("NewApi")   
public class Fragmen1 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) {  
        // TODO Auto-generated method stub  
        super.onAttach(activity);  
        //当前fragment从activity重写了回调接口  得到接口的实例化对象  
        callBackValue =(CallBackValue) getActivity();  
    }  
      
      
    @Override  
    public View onCreateView(LayoutInflater inflater, ViewGroup container,  
            Bundle savedInstanceState) {  
        // TODO Auto-generated method stub  
        View view = inflater.inflate(R.layout.fragment_layout1, container, false);  
         btn1 = (Button) view.findViewById(R.id.btn1);  
         et1 = (EditText) view.findViewById(R.id.et1);  
         btn1.setOnClickListener(new OnClickListener() {  
              
            @Override  
            public void onClick(View v) {  
                // TODO Auto-generated method stub  
                String strValue = et1.getText().toString().trim();  
                callBackValue.SendMessageValue(strValue);  
              
            }  
        });  
          
        return view;  
    }  
    //定义一个回调接口  
    public interface CallBackValue{  
        public void SendMessageValue(String strValue);  
    }  
}  

 

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