Android:如何在 AlertDialog 中获得带有图像的复选框列表

Question

我需要像上图一样的 AlertDialog，但带有复选框

我检查了这个 Post 并创建了以下代码

animal_text.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout android:padding="10dp" android:layout_height="fill_parent"    android:layout_width="fill_parent" android:orientation="horizontal"     android:id="@+id/layout_root" xmlns:android="http://schemas.android.com/apk/res/android">

<CheckedTextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/miastorow_text"
    android:layout_width="fill_parent"
    android:layout_height="?android:attr/listPreferredItemHeight"
    android:textAppearance="?android:attr/textAppearanceLarge"
    android:gravity="center_vertical"
    android:checkMark="?android:attr/listChoiceIndicatorMultiple"
    android:paddingLeft="6dip"
    android:paddingRight="6dip"
    android:textColor="#000"/>
</LinearLayout>

ma​​in.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" >

<Button
    android:id="@+id/button1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Button" />

</LinearLayout>

ImageActivity.java

package com.imagetest;
import android.app.Activity;
import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.content.DialogInterface.OnClickListener;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.CheckedTextView;
import android.widget.ListAdapter;

public class ImageActivity extends Activity {
    /** Called when the activity is first created. */
    private static final String TAG = "HelloWorld";
    Animal[] _animals;
    Button btnStart;
    public static int count =0;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        System.out.println("on create");
        setContentView(R.layout.main); 
        loadAnimals();
        btnStart = (Button)findViewById(R.id.button1);
        final Button button = (Button) findViewById(R.id.button1);
        button.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                 System.out.println("##########");
                 handlePush(v);
            }
        });
        //btnStart.setOnClickListener((android.view.View.OnClickListener) btnStartListener);
        System.out.println("on create after main");
        System.out.println("on create before load animals");

    }   

    private void loadAnimals() {
         System.out.println("########## 1  ");
        _animals = new Animal[3];

        // define the display string, the image, and the value to use
        // when the choice is selected
        _animals[0]  = new Animal( "dog", getImg( R.drawable.dog),"dog_sitting" );
        _animals[1]  = new Animal( "cat", getImg( R.drawable.cat),"cat_sitting" );
        _animals[1]  = new Animal( "bird", getImg( R.drawable.bird),"bird_sitting" );

    }

    private Drawable getImg( int res )
    {
         System.out.println("########## 3  ");
        Drawable img = getResources().getDrawable( res );
        img.setBounds( 0, 0, 48, 48 );
        return img;
    }

    public void handlePush( View target ) {
     System.out.println("##########  button clicked handle push");
    // define the list adapter with the choices
        ListAdapter adapter = new AnimalAdapter( this, _animals );

        final AlertDialog.Builder ad = new AlertDialog.Builder(this);
        // define the alert dialog with the choices and the action to take
        // when one of the choices is selected
        ad.setSingleChoiceItems( adapter, -1, new OnClickListener() {
            public void onClick(DialogInterface dialog, int which) {
                // a choice has been made!
                String selectedVal = _animals[which].getVal();
                Log.d(TAG, "chosen " + selectedVal );
                dialog.dismiss();
            }
        });
        ad.show();
   }

    static class AnimalAdapter extends ArrayAdapter<Animal> {

        private static final int RESOURCE = R.layout.animal_text;
        private LayoutInflater inflater;

        static class ViewHolder {
            CheckedTextView nameTxVw;
        }

        //@SuppressWarnings("unchecked")
        public AnimalAdapter(Context context, Animal[] objects)
        {
            super(context, RESOURCE, objects);
            inflater = LayoutInflater.from(context);
        }

        @Override
        public View getView(int position, View convertView, ViewGroup parent)
        {
            count=count+1;
             System.out.println("################ "+count+" position  "+position+" parent "+parent);
            ViewHolder holder;
            System.out.println("##########  getview outside if 1 "+count);
            if ( convertView == null ) {
                 System.out.println("##########  getview if 1 "+count);
                // inflate a new view and setup the view holder for future use
                convertView = inflater.inflate( RESOURCE, null );

                holder = new ViewHolder();
                holder.nameTxVw =
                    (CheckedTextView) convertView.findViewById(R.id.miastorow_text);
                convertView.setTag( holder );
            }  else {
                System.out.println("##########  getview else 1 "+count+"  convert "+convertView.toString());
                // view already defined, retrieve view holder
                holder = (ViewHolder) convertView.getTag();
            }

            Animal cat = (Animal) getItem( position );
            if ( cat == null ) {
                System.out.println("##########  getview if 2");
                //Log.e( TAG, “Invalid category for position: ”+position);
            }
            holder.nameTxVw.setText( cat.getName() );
            holder.nameTxVw.setCompoundDrawables( cat.getImg(), null, null, null );

            return convertView;
        }
    }



    class Animal {
        private String   _name;
        private Drawable _img;
        private String   _val;

        public Animal( String name, Drawable img, String val ) {

             System.out.println("##########  2");
            _name = name;
            _img = img;
            _val = val;
        }

        public String getName() {
            return _name;
        }

        public Drawable getImg() {
            return _img;
        }

        public String getVal() {
            return _val;
        }
    }    

}

我遇到了一个空指针异常。我不知道如何解决它，因为我是 Android 的新手。请尽快帮助我。

我的logcat详情如下

07-26 12:14:12.436: DEBUG/AndroidRuntime(13275): Shutting down VM
07-26 12:14:12.436: WARN/dalvikvm(13275): threadid=1: thread exiting with uncaught exception (group=0x400205a0)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275): FATAL EXCEPTION: main
07-26 12:14:12.456: ERROR/AndroidRuntime(13275): java.lang.NullPointerException
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at com.imagetest.ImageActivity$AnimalAdapter.getView(ImageActivity.java:130)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.AbsListView.obtainView(AbsListView.java:1409)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.ListView.measureHeightOfChildren(ListView.java:1264)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.ListView.onMeasure(ListView.java:1127)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.View.measure(View.java:8526)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3228)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.View.measure(View.java:8526)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3228)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at com.android.internal.widget.WeightedLinearLayout.onMeasure(WeightedLinearLayout.java:60)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.View.measure(View.java:8526)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3228)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.View.measure(View.java:8526)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3228)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.View.measure(View.java:8526)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewRoot.performTraversals(ViewRoot.java:902)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.view.ViewRoot.handleMessage(ViewRoot.java:1957)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.os.Handler.dispatchMessage(Handler.java:99)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.os.Looper.loop(Looper.java:150)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at android.app.ActivityThread.main(ActivityThread.java:4277)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at java.lang.reflect.Method.invokeNative(Native Method)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at java.lang.reflect.Method.invoke(Method.java:507)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
07-26 12:14:12.456: ERROR/AndroidRuntime(13275):     at dalvik.system.NativeStart.main(Native Method)
07-26 12:14:12.476: WARN/ActivityManager(124):   Force finishing activity com.imagetest/.ImageActivity
07-26 12:14:12.976: WARN/ActivityManager(124): Activity pause timeout for HistoryRecord{4081ff48 com.imagetest/.ImageActivity}
07-26 12:14:13.056: INFO/CarouselTimeLog(259): onStart() finish: 1343285053068

Answer 1

//你复制粘贴错了

 _animals[0]  = new Animal( "dog", getImg( R.drawable.dog),"dog_sitting" );
_animals[1]  = new Animal( "cat", getImg( R.drawable.cat),"cat_sitting" );
_animals[1]  = new Animal( "bird", getImg( R.drawable.bird),"bird_sitting" );

//改变如下 _animals[2] = new Animal( "bird", getImg( R.drawable.bird),"bird_sitting");

//删除下面任意一行

 btnStart = (Button)findViewById(R.id.button1);
 final Button button = (Button) findViewById(R.id.button1);