ListView適配器不適用於AppCompatActivity

Question

我有一個應用程序在API 15-19上工作完美，並且在將它移植到AppCompat時遇到問題：當我將MainActivity extends FragmentActivity更改爲MainActivity extends AppCompatActivity時，編譯失敗（也是I更新所有適當的庫並用getSupportFragmentManager()替換getFragmentManager()）。試圖找出是什麼原因導致這個錯誤，我發現它時，ListView的適配器填充項按鈕（即第一按鈕id="@+id/time_field"）之一發生：

listitem_task.xml：

<?xml version="1.0" encoding="utf-8"?> 
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
       android:layout_width="wrap_content" 
       android:layout_height="wrap_content" 
       android:id="@+id/item_layout" 
    android:paddingBottom="5dp"> 

    <Button 
     android:id="@+id/time_field" 
     android:layout_width="115dp" 
     android:layout_height="wrap_content" 
     android:layout_alignParentTop="true" 
     android:layout_alignParentLeft="true" 
     android:layout_alignParentStart="true" 
     android:layout_marginRight="5dp" 
     android:layout_marginEnd="5dp" 
     android:textColor="@color/black_col" 
     android:paddingLeft="2dp" 
     android:paddingRight="2dp" 
     android:singleLine="true" 
     android:textSize="18sp" 
     android:longClickable="false" 
     android:enabled="true" 
     android:focusable="false" 
     android:clickable="false" 
     android:focusableInTouchMode="false" 
     android:layout_alignParentBottom="false" /> 

    <Button 
     android:layout_width="match_parent" 
     android:layout_height="wrap_content" 
     android:id="@+id/task_field" 
     android:layout_alignParentTop="true" 
     android:layout_toRightOf="@+id/time_field" 
     android:layout_toEndOf="@+id/time_field" 
     android:textColor="@color/black_col" 
     android:gravity="start|center" 
     android:paddingLeft="10dp" 
     android:clickable="false" 
     android:enabled="true" 
     android:focusable="false" 
     android:focusableInTouchMode="false" 
     android:longClickable="false" 
     android:paddingRight="10dp" 
     android:maxLines="2" /> 
</RelativeLayout> 

所以，這當我（// FORMATTING TIME-FIELD:後線）註釋掉負責線在ListView格式化這個按鈕適配器錯誤不會發生：

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

import java.util.ArrayList; 

public class TaskAdapter extends BaseAdapter { 
    private ArrayList<Task> taskList; 
    private Context context; 

    public TaskAdapter(ArrayList<Task> taskList, Context context) { 
     this.taskList = taskList; 
     this.context = context; 
    } 

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

    @Override 
    public Object getItem(int position) { 
     return taskList.get(position); 
    } 

    @Override 
    public long getItemId(int itemId) { 
     return itemId; 
    } 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     Task task = taskList.get(position); 
     if (convertView == null) { 
      convertView = LayoutInflater.from(context).inflate(R.layout.listitem_task, parent, false); 
     } 

     int taskHrsEnd = task.getHrsEnd(); 
     int taskHrsStart = task.getHrsStart(); 
     int taskMinsStart = task.getMinsStart(); 
     int taskMinsEnd = task.getMinsEnd(); 
     Button taskField = (Button) convertView.findViewById(R.id.task_field); 
     taskField.setText(task.getName() + " (" + task.getDurationMins() + "m)"); 
     Button timeField = (Button) convertView.findViewById(R.id.time_field); 

     if (task.isChecked()) { 
      taskField.setBackgroundResource(R.color.transparent_white_col); 
      timeField.setBackgroundResource(R.color.transparent_white_col); 
     } else { 
      taskField.setBackgroundResource(R.color.white_col); 
      timeField.setBackgroundResource(R.color.white_col); 
     } 

     // FORMATTING TIME-FIELD: 
     if (taskHrsStart < 10 && taskMinsStart > 9) {     
      timeField.setText("0" + taskHrsStart + ":" + taskMinsStart); 
     } 
     if (taskHrsStart > 9 && taskMinsStart < 10) { 
      timeField.setText(taskHrsStart + ":0" + taskMinsStart); 
     } 
     if (taskHrsStart > 9 && taskMinsStart > 9) { 
      timeField.setText(taskHrsStart + ":" + taskMinsStart); 
     } 
     if (taskHrsStart < 10 && taskMinsStart < 10) { 
      timeField.setText("0" + taskHrsStart + ":0" + taskMinsStart); 
     } 
     if (taskHrsEnd < 10 && taskMinsEnd > 9) { 
      timeField.append(" - " + "0" + taskHrsEnd + ":" + taskMinsEnd); 
     } 
     if (taskHrsEnd > 9 && taskMinsEnd < 10) { 
      timeField.append(" - " + taskHrsEnd + ":0" + taskMinsEnd); 
     } 
     if (taskHrsEnd > 9 && taskMinsEnd > 9) { 
      timeField.append(" - " + taskHrsEnd + ":" + taskMinsEnd); 
     } 
     if (taskHrsEnd < 10 && taskMinsEnd < 10) { 
      timeField.append(" - " + "0" + taskHrsEnd + ":0" + task.getMinsEnd()); 
     } 


     return convertView; 
    } 
} 

而且我從MainActivity.java稱之爲：

public class MainActivity extends AppCompatActivity implements LoaderManager.LoaderCallbacks<Cursor>, AdapterView.OnItemClickListener { 
    private ArrayList<Task> taskList; 
    private ListView listView; 
    private TaskAdapter taskAdapter; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

     init(); 
    } 

    private void init() { 
     findViewById(R.id.btn_back).setVisibility(View.GONE); 
     findViewById(R.id.btn_delete_selected).setVisibility(View.GONE); 

     taskList = new ArrayList<>(); 

     viewTimeRemain = (TextView) findViewById(R.id.time_remain_view); 
     listView = (ListView) findViewById(R.id.task_list); 
     listView.setOnItemClickListener(this); 
     registerForContextMenu(listView); 
     taskAdapter = new TaskAdapter(taskList, this); 
    } 

    public void addTask(View view) { 
     EditText taskName = (EditText) findViewById(R.id.taskName); 
     EditText taskDuration = (EditText) findViewById(R.id.taskDuration); 
     Task task = new Task();             
     task.setName(taskName.getText().toString());        
     task.setDurationMins(Integer.parseInt(taskDuration.getText().toString())); 
     setTaskTimeInterval(task); 
     taskList.add(task);  
     fillList(taskAdapter); 

    private void fillList(TaskAdapter taskAdapter) { 
     listView.setAdapter(taskAdapter);    
    } 
} 

崩潰報告：

java.lang.IndexOutOfBoundsException              
    at android.graphics.Paint.getTextRunAdvances(Paint.java:1879)      
    at android.text.TextLine.handleText(TextLine.java:747)        
    at android.text.TextLine.handleRun(TextLine.java:898)        
    at android.text.TextLine.measureRun(TextLine.java:414)        
    at android.text.TextLine.measure(TextLine.java:293)         
    at android.text.TextLine.metrics(TextLine.java:267)         
    at android.text.Layout.getLineExtent(Layout.java:976)        
    at android.text.Layout.getLineMax(Layout.java:932)         
    at android.text.Layout.getLineLeft(Layout.java:889)         
    at android.widget.TextView.bringTextIntoView(TextView.java:6652)     
    at android.widget.TextView.onPreDraw(TextView.java:4696)       
    at android.view.ViewTreeObserver.dispatchOnPreDraw(ViewTreeObserver.java:847)  
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1867)    
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:996)      
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5600)   
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:761)   
    at android.view.Choreographer.doCallbacks(Choreographer.java:574)     
    at android.view.Choreographer.doFrame(Choreographer.java:544)      
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:747) 
    at android.os.Handler.handleCallback(Handler.java:733)        
    at android.os.Handler.dispatchMessage(Handler.java:95)        
    at android.os.Looper.loop(Looper.java:136)           
    at android.app.ActivityThread.main(ActivityThread.java:5001)      
    at java.lang.reflect.Method.invokeNative(Native Method)        
    at java.lang.reflect.Method.invoke(Method.java:515) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:785) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:601)      
    at dalvik.system.NativeStart.main(Native Method) 

請幫我理解這個問題！謝謝！

Answer 1

我剛剛發現，這個錯誤發生時，我想.append（）文本到TextView（按鈕）。所以我使用了StringBuffer來構建我需要的文本，然後將此文本設置爲我的TextView（無需追加），現在它可以工作。