我想加載一個片段，但應用程序崩潰

Question

我試圖獲得一個片段加載列表中的項目時單擊。項目文本是「營養素/目標計算器」。當我點擊MainActivity.java文件中的列表項時程序崩潰。

MainActivity.java

package com.example.crims.fooddiarytools; 

import android.app.Fragment; 
import android.app.FragmentTransaction; 
import android.app.ListActivity; 
import android.os.Bundle; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ListView; 
import android.widget.Toast; 


public class MainActivity extends ListActivity { 

    private ListViewCustomAdapter mAdapter; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     mAdapter = new ListViewCustomAdapter(this); 
     mAdapter.addSectionHeaderItem("Food"); 
     mAdapter.addItem("Nutrient/Target calculator"); 


     ListView lv = (ListView) findViewById(android.R.id.list); 
     lv.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView parent, View v, 
            int position, long id) { 
       String itemInList = (String)parent.getItemAtPosition(position); 


       if(itemInList.equals("Nutrient/Target calculator")) { 
        // this won't load it crashes ////////////////////////////// 
        Fragment fragment = new NutrientTargetCalculator(); 
        FragmentTransaction ft = getFragmentManager().beginTransaction(); 

        ft.replace(android.R.id.list, fragment); 
        ft.commit(); 
       } 

       Toast.makeText(getBaseContext(), itemInList, Toast.LENGTH_SHORT).show(); 
       mAdapter.myCliquedPosition = position; 
       mAdapter.notifyDataSetInvalidated(); 
      } 

     }); 
    } 
} 

NutrientTargetCalculator.java

package com.example.crims.fooddiarytools; 
import android.app.Fragment; 
import android.os.Bundle; 
import android.support.annotation.Nullable; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.Button; 
import android.widget.Spinner; 
import android.widget.TextView; 

public class NutrientTargetCalculator extends Fragment{ 

    private static Button buttonNutrient; 
    private static Button buttonNutrientTarget; 
    private static Spinner foodUnitSpinner; 
    private static Spinner foodNutrientsSpinner; 
    private static TextView editTextNutrients; 
    private static TextView editTextServingSize; 
    private static TextView editTextScaleWeight; 
    private static TextView editTextNutrientOutput; 
    private static TextView editTextNutrientTarget; 
    private static TextView textViewServingOutPut1; 

    View myView; 

    @Nullable 
    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { 
     myView = inflater.inflate(R.layout.nutrient_target_calculator, container, false); 
     return myView; 
    } 

} 

ListViewCustomAdapter.java

package com.example.crims.fooddiarytools; 

import android.content.Context; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.TextView; 

import java.util.ArrayList; 
import java.util.TreeSet; 

/** 
* Created by crims on 12/22/2016. 
*/ 

public class ListViewCustomAdapter extends BaseAdapter{ 
    private static final int TYPE_ITEM = 0; 
    private static final int TYPE_SEPARATOR = 1; 

    private ArrayList<String> mData = new ArrayList<String>(); 
    private TreeSet<Integer> sectionHeader = new TreeSet<Integer>(); 

    private LayoutInflater mInflater; 
    public int myCliquedPosition; 

    public ListViewCustomAdapter(Context context) { 
     mInflater = (LayoutInflater) context 
       .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

    public void addItem(final String item) { 
     mData.add(item); 
     notifyDataSetChanged(); 
    } 

    public void addSectionHeaderItem(final String item) { 
     mData.add(item); 
     sectionHeader.add(mData.size() - 1); 
     notifyDataSetChanged(); 
    } 

    @Override 
    public int getItemViewType(int position) { 
     return sectionHeader.contains(position) ? TYPE_SEPARATOR : TYPE_ITEM; 
    } 

    @Override 
    public int getViewTypeCount() { 
     return 2; 
    } 

    @Override 
    public int getCount() { 
     return mData.size(); 
    } 

    @Override 
    public String getItem(int position) { 
     return mData.get(position); 
    } 

    @Override 
    public long getItemId(int position) { 
     return position; 
    } 
     public static class ViewHolder { 
     public TextView textView; 
    } 

    public View getView(int position, View convertView, ViewGroup parent) { 
     ViewHolder holder = null; 
     int rowType = getItemViewType(position); 

     if (convertView == null) { 
      holder = new ViewHolder(); 
      switch (rowType) { 
       case TYPE_ITEM: 
        convertView = mInflater.inflate(R.layout.list_view_text, null); 
        holder.textView = (TextView) convertView.findViewById(R.id.text); 
        break; 
       case TYPE_SEPARATOR: 
        convertView = mInflater.inflate(R.layout.list_view_box, null); 
        holder.textView = (TextView) convertView.findViewById(R.id.textSeparator); 
        break; 
      } 
      convertView.setTag(holder); 
     } else { 
      holder = (ViewHolder) convertView.getTag(); 
     } 
     holder.textView.setText(mData.get(position)); 

     return convertView; 
    } 
} 

這裏是輸出

12-22 23:36:43.716 4518-4518/? I/art: Not late-enabling -Xcheck:jni (already on) 
    12-22 23:36:43.922 4518-4518/com.example.crims.testing W/System: ClassLoader referenced unknown path: /data/app/com.example.crims.testing-1/lib/x86 
    12-22 23:36:43.926 4518-4518/com.example.crims.testing I/InstantRun: Instant Run Runtime started. Android package is com.example.crims.testing, real application class is null. 
    12-22 23:36:45.027 4518-4518/com.example.crims.testing W/System: ClassLoader referenced unknown path: /data/app/com.example.crims.testing-1/lib/x86 
    12-22 23:36:45.257 4518-4518/com.example.crims.testing W/art: Before Android 4.1, method android.graphics.PorterDuffColorFilter android.support.graphics.drawable.VectorDrawableCompat.updateTintFilter(android.graphics.PorterDuffColorFilter, android.content.res.ColorStateList, android.graphics.PorterDuff$Mode) would have incorrectly overridden the package-private method in android.graphics.drawable.Drawable 
    12-22 23:36:45.556 4518-4542/com.example.crims.testing D/OpenGLRenderer: Use EGL_SWAP_BEHAVIOR_PRESERVED: true 
    12-22 23:36:45.612 4518-4542/com.example.crims.testing I/OpenGLRenderer: Initialized EGL, version 1.4 
    12-22 23:36:45.673 4518-4542/com.example.crims.testing E/EGL_emulation: tid 4542: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
    12-22 23:36:45.673 4518-4542/com.example.crims.testing W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xaa413620, error=EGL_BAD_MATCH 
    12-22 23:37:06.989 4518-4542/com.example.crims.testing E/Surface: getSlotFromBufferLocked: unknown buffer: 0xae4710e0 
    12-22 23:37:10.167 4518-4542/com.example.crims.testing E/EGL_emulation: tid 4542: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
    12-22 23:37:10.167 4518-4542/com.example.crims.testing W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xaa413620, error=EGL_BAD_MATCH 
    12-22 23:38:40.868 4518-4542/com.example.crims.testing E/Surface: getSlotFromBufferLocked: unknown buffer: 0xaa1d5170 
    12-22 23:38:45.673 4518-4542/com.example.crims.testing E/EGL_emulation: tid 4542: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
    12-22 23:38:45.673 4518-4542/com.example.crims.testing W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xaa413620, error=EGL_BAD_MATCH 
    12-22 23:40:15.359 4518-4542/com.example.crims.testing E/Surface: getSlotFromBufferLocked: unknown buffer: 0xae4710e0 
    12-22 23:40:44.665 4518-4542/com.example.crims.testing E/EGL_emulation: tid 4542: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
    12-22 23:40:44.665 4518-4542/com.example.crims.testing W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xaa413620, error=EGL_BAD_MATCH 
    12-22 23:43:30.414 4518-4542/com.example.crims.testing E/Surface: getSlotFromBufferLocked: unknown buffer: 0xae4710e0 
    12-22 23:43:34.790 4518-4542/com.example.crims.testing E/EGL_emulation: tid 4542: eglSurfaceAttrib(1165): error 0x3009 (EGL_BAD_MATCH) 
    12-22 23:43:34.790 4518-4542/com.example.crims.testing W/OpenGLRenderer: Failed to set EGL_SWAP_BEHAVIOR on surface 0xaa413620, error=EGL_BAD_MATCH 

Answer 1

你不能取代android.R.id.list。使用此步驟：

1. 延伸活動，不ListActivity
2. 創建在res /佈局，將有一個LinearLayout中的一些ID（前list_wrapper。）自定義佈局，並在LinearLayout中一個列表視圖中的一些ID（前。 calc_listview）
3. 使用calc_listview代替android.R.id.list
4. 替換

ft.replace（android.R.id.list，片段）;

與

ft.replace（R.id.list_wrapper，片段）;