我需要像上图一样的 AlertDialog 但带有复选框
我检查了这篇文章，并创建了以下代码
动物文本.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>
主要的.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;
}
}
}
我得到一个空指针异常..我不知道如何解决它，因为我是 Android 新手..请尽快帮助我。
我的logcat详细信息如下
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