Fragment与Activity的通信

最新推荐文章于 2025-05-27 05:08:17 发布

翻译最新推荐文章于 2025-05-27 05:08:17 发布 · 182 阅读

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#Android #Fragment与Activity通信

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本文介绍了一种在Android应用中实现Fragment与Activity之间通信的方法。主要通过两种方式：接口回调和广播接收器，来实现在Fragment中触发事件并更新Activity中的UI内容。

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目的：fragment向Activity传递信息，点击按钮通过接口或者广播传递信息

略解：activity_main中有一个LinearLayout（@+id/fragment_ll）的控件,此控件在MainActivity中通过getFragmentManager().beginTransaction()的replace（int,fragment）被自定义的MyFragment(继承自Fragment)代替。

接口传递：

在MyFragment中：

public interface Submit {
public void submit(String userStr, String passStr);

}

在OnAttch中：submit = (Submit) activity;

在按钮的点击响应事件中：

submit = (Submit) getActivity();

submit.submit(userEdt.getText().toString().trim(), passEdt .getText().toString().trim());

在MainActivity（implements Submit）中：

Fragment fragment = new MyFragment();
FragmentTransaction fm = getFragmentManager().beginTransaction();
fm.replace(R.id.fragment_ll, fragment);
fm.commit();

intentFilter = new IntentFilter();
intentFilter.addAction("android.text_change");
broadReceiver = new BroadReceiver();
registerReceiver(broadReceiver, intentFilter);

@Override
public void submit(String userStr, String passStr) {
txt.setText(userStr+","+passStr);

}

广播传递：

在MyFragment中：

Intent intent = new Intent("android.text_change");
intent.putExtra("text", userEdt.getText().toString()+","+passEdt.getText().toString());

getActivity().sendBroadcast(intent);

在MainActivity中：

Fragment fragment = new MyFragment();
FragmentTransaction fm = getFragmentManager().beginTransaction();
fm.replace(R.id.fragment_ll, fragment);
fm.commit();

intentFilter = new IntentFilter();
intentFilter.addAction("android.text_change");
broadReceiver = new BroadReceiver();
registerReceiver(broadReceiver, intentFilter);

public class BroadReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Bundle data= intent.getExtras();
txt.setText(data.getString("text"));
}

}

总代码如下：

MainActivity:

package com.example.tongxin;

import com.example.tongxin.MyFragment.Submit;

import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentTransaction;
import android.content.BroadcastReceiver;
import android.content.Context;
import android.content.Intent;
import android.content.IntentFilter;
import android.os.Bundle;
import android.view.Window;
import android.widget.TextView;
import android.widget.Toast;

public class MainActivity extends Activity implements Submit {
TextView txt;
private IntentFilter intentFilter;
private BroadReceiver broadReceiver;

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

initview();

intentFilter = new IntentFilter();
intentFilter.addAction("android.text_change");
broadReceiver = new BroadReceiver();
registerReceiver(broadReceiver, intentFilter);

}
private void initview() {
txt=(TextView) findViewById(R.id.txt);
Fragment fragment = new MyFragment();
FragmentTransaction fm = getFragmentManager().beginTransaction();
fm.replace(R.id.fragment_ll, fragment);
fm.commit();
}
@Override
public void submit(String userStr, String passStr) {
txt.setText(userStr+","+passStr);
}
public class BroadReceiver extends BroadcastReceiver {
@Override
public void onReceive(Context context, Intent intent) {
Bundle data= intent.getExtras();
txt.setText(data.getString("text"));
}

}

}

MyFragment.java:

package com.example.tongxin;

import android.app.Activity;
import android.app.Fragment;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.View.OnClickListener;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.EditText;

public class MyFragment extends Fragment {
Context context;
Submit submit;
EditText userEdt;
EditText passEdt;
Button inBtn;
Button brBtn;

public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.my_fragment, container, false);
context = getActivity();
return view;
}
public void onActivityCreated(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onActivityCreated(savedInstanceState);
initview();
}
@Override
public void onAttach(Activity activity) {
// TODO Auto-generated method stub
super.onAttach(activity);
submit = (Submit) activity;
}
public interface Submit {
public void submit(String userStr, String passStr);
}
private void initview() {
userEdt = (EditText) getView().findViewById(R.id.username_edt);
passEdt = (EditText) getView().findViewById(R.id.password_edt);
inBtn = (Button) getView().findViewById(R.id.interface_btn);
inBtn.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
submit = (Submit) getActivity();
submit.submit(userEdt.getText().toString().trim(), passEdt
.getText().toString().trim());
}
});

brBtn = (Button) getView().findViewById(R.id.broadcast_btn);
brBtn.setOnClickListener(new OnClickListener() {

@Override
public void onClick(View arg0) {
Intent intent = new Intent("android.text_change");
intent.putExtra("text", userEdt.getText().toString()+","+passEdt.getText().toString());
getActivity().sendBroadcast(intent);
}
});
}

}

activity_main.xml:

</RelativeLayout>

my_fragment.xml:

<?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" >
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<EditText
android:id="@+id/username_edt"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />

<EditText
android:id="@+id/password_edt"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />

<Button
android:id="@+id/interface_btn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="接口按钮" />

<Button
android:id="@+id/broadcast_btn"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:text="广播按钮" />
</LinearLayout>

</LinearLayout>