我是 Android 新手，正在尝试自学。但是我在使用 Fragments 时遇到了困难。我正在创建一个简单的应用程序来学习 fragment 。我认为这可能看起来很愚蠢，但我真的无法让它发挥作用。

我只想在 Fragment_One 中单击一个按钮 (buttonSayHi)，Fragment_One 应该被 Fragment_Two 替换。

我不确定何时调用 fragment 代码以及我应该在哪里编写代码来调用第二个 fragment 。我收到错误:无法启动 Activity 组件。

但是，如果我放弃按钮的监听器并且 fragment 显示在 Activity 中，则代码可以正常工作。

我进行了大量研究，阅读了 developer.android.com 上的 fragment 教程以及 Lars Vogella 的教程。我觉得我的概念不清楚。

任何帮助将不胜感激。

以下是代码:

activity_main.xml

<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/frameLayoutFragmentContainer"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent" >

</FrameLayout>

fragment_one.xml

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <EditText
        android:id="@+id/editTextPersonName"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:inputType="textPersonName" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/buttonSayHi"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="Say Hi" 
        android:onClick="onButtonClicked"/>

</LinearLayout>

fragment_two.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:orientation="vertical" >

    <TextView
        android:id="@+id/textViewResult"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="I will say Hi!" />

</LinearLayout>

MainActivity.java

package com.example.fragmenttutorial;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;

public class MainActivity extends Activity{

    View view;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

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

        Fragment fragmentOne = new FragmentOne();

        fragmentTransaction.add(R.id.frameLayoutFragmentContainer, fragmentOne);
        fragmentTransaction.addToBackStack(null);

        fragmentTransaction.commit();
    }

    protected void onButtonClicked()
    {
        if(view.getId() == R.id.buttonSayHi){
            Fragment fragmentTwo = new FragmentTwo();

            fragmentTransaction.replace(R.id.frameLayoutFragmentContainer, fragmentTwo);
            fragmentTransaction.addToBackStack(null);

            fragmentTransaction.commit();   

        }

    }
}

FragmentOne.java

package com.example.fragmenttutorial;

import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FragmentOne extends Fragment{

    View view;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_one, container, false);
        return view;
    }

//  protected void onButtonClicked()
//  {
//      if(view.getId() == R.id.buttonSayHi){
//          Fragment fragmentTwo = new FragmentTwo();
//
//          fragmentTransaction.replace(R.id.frameLayoutFragmentContainer, fragmentTwo);
//          fragmentTransaction.addToBackStack(null);
//
//          fragmentTransaction.commit();   
//
//      }
//
//  }
}

我已经注释掉了 fragment 中的点击代码。我也尝试在 fragment 中实现 onClickListener。

FragmentTwo.java

package com.example.fragmenttutorial;

import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

public class FragmentTwo extends Fragment{

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_two, container, false);
        return view;    
    }
}

编辑:我已经从我的 XML 代码中删除了 android:onClick="onButtonClicked"行。并编辑了以下文件，但它仍然不起作用。你们能给我提供一个没有 android:onClick="onButtonClicked"行的工作示例吗？

MainActivity.java

package com.example.fragmenttutorial;

import android.os.Bundle;
import android.view.View;
import android.app.Activity;
import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;

public class MainActivity extends Activity{

    View view;
    Fragment fragmentOne;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

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

        fragmentOne = new FragmentOne();

        fragmentTransaction.add(R.id.frameLayoutFragmentContainer, fragmentOne);
        fragmentTransaction.addToBackStack(null);

        fragmentTransaction.commit();       
    }
}

FragmentOne.java

package com.example.fragmenttutorial;

import android.app.Fragment;
import android.app.FragmentManager;
import android.app.FragmentTransaction;
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;

public class FragmentOne extends Fragment implements OnClickListener{

    View view;
    Fragment fragmentTwo;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View view = inflater.inflate(R.layout.fragment_one, container, false);
        Button buttonSayHi = (Button) view.findViewById(R.id.buttonSayHi);
        buttonSayHi.setOnClickListener(this);
        return view;
    }

    @Override
    public void onClick(View v) {

        fragmentTwo = new FragmentTwo();

        fragmentTransaction.replace(R.id.frameLayoutFragmentContainer, fragmentTwo);
        fragmentTransaction.addToBackStack(null);

        fragmentTransaction.commit();   

    }
}

感谢您的宝贵建议。

最佳答案

你的 fragment 类应该实现 OnClickListener

public class SmartTvControllerFragment extends Fragment implements View.OnClickListener

然后获取 View 、链接按钮并设置 onClickListener，如下例所示

 View view;

@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

    view = inflater.inflate(R.layout.smart_tv_controller_fragment, container, false);
    upButton = (Button) view.findViewById(R.id.smart_tv_controller_framgment_up_button);
    upButton.setOnClickListener(this);
    return view;
 }

然后添加 onClickListener 方法，做你想做的事。

@Override
public void onClick(View v) {
 //do what you want to do when button is clicked
    switch (v.getId()) {
        case R.id.textView_help:
            switchFragment(HelpFragment.TAG);
            break;
        case R.id.textView_settings:
            switchFragment(SettingsFragment.TAG);
            break;
    }
}

这是我的代码示例，但我希望你能理解

关于android - android中 fragment 中按钮的按钮监听器，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/18711433/