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我正在构建一个警报框，它有一个 char 元素数组，用作多选复选框的数据。我的问题是如何使此警报框根据所选项目顺序将值返回为 1、2、3？IE。如果我选择 mercur 和 venus，我必须将值设为 1,2。我将如何实施？正如您在我尝试使用 for 循环后看到的那样，它现在正在打印选中了哪个复选框。请帮帮我！！！

  public class MultiActivity extends Activity {
  protected CharSequence[] _options = { "Mercury", "Venus", "Earth", "Mars",  
  "Jupiter", "Saturn", "Uranus", "Neptune" };
  protected boolean[] _selections =  new boolean[ _options.length ];

protected Button _optionsButton;

/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    _optionsButton = ( Button ) findViewById( R.id.button1);
    _optionsButton.setOnClickListener( new ButtonClickHandler()  );
}


public class ButtonClickHandler implements View.OnClickListener {
    public void onClick( View view ) {
        showDialog( 0 );
    }
}

@Override
protected Dialog onCreateDialog( int id ) 
{
    return 
    new AlertDialog.Builder( this )
        .setTitle( "Planets" )
        .setMultiChoiceItems( _options, _selections, new DialogSelectionClickHandler() )
        .setPositiveButton( "OK", new DialogButtonClickHandler() )
        .create();
}

public class DialogSelectionClickHandler implements DialogInterface.OnMultiChoiceClickListener
{
    public void onClick( DialogInterface dialog, int clicked, boolean selected )
    {
        Log.i( "ME", _options[ clicked ] + " selected: " + selected );
    }
}
public class DialogButtonClickHandler implements DialogInterface.OnClickListener
{
    public void onClick( DialogInterface dialog, int clicked )
    {
        switch( clicked )
        {
            case DialogInterface.BUTTON_POSITIVE:
                printSelectedPlanets();
                break;
        }
    }
}

protected void printSelectedPlanets(){
    for( int i = 0; i < _options.length; i++ ){
        Log.i( "ME", _options[ i ] + " selected: " + _selections[i] );
        String abc = _options[ i ] + " selected: " + _selections[i];
        TextView ab = (TextView)findViewById(R.id.textView1);
        ab.setText(abc);
        System.out.print(abc);

    }
}

}

当我尝试运行下面提到的代码时，请参阅我的 logcat 中打印了以下错误。

11-21 14:23:59.905: E/AndroidRuntime(439): FATAL EXCEPTION: main 11-21 14:23:59.905: E/AndroidRuntime(439): java.lang.NullPointerException 11-21 14:23:59.905: E/AndroidRuntime(439): at com.workspace.multi.peek$2.onClick(peek.java:47) 11-21 14:23:59.905: E/AndroidRuntime(439): at com.android.internal.app.AlertController$AlertParams$4.onItemClick(AlertController.java:886) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.widget.AdapterView.performItemClick(AdapterView.java:284) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.widget.ListView.performItemClick(ListView.java:3382) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1696) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.os.Handler.handleCallback(Handler.java:587) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.os.Handler.dispatchMessage(Handler.java:92) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.os.Looper.loop(Looper.java:123) 11-21 14:23:59.905: E/AndroidRuntime(439): at android.app.ActivityThread.main(ActivityThread.java:4627) 11-21 14:23:59.905: E/AndroidRuntime(439): at java.lang.reflect.Method.invokeNative(Native Method) 11-21 14:23:59.905: E/AndroidRuntime(439): at java.lang.reflect.Method.invoke(Method.java:521) 11-21 14:23:59.905: E/AndroidRuntime(439): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 11-21 14:23:59.905: E/AndroidRuntime(439): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 11-21 14:23:59.905: E/AndroidRuntime(439): at dalvik.system.NativeStart.main(Native Method) 11-21 14:33:05.145: D/AndroidRuntime(495): Shutting down VM 11-21 14:33:05.145: W/dalvikvm(495): threadid=1: thread exiting with uncaught exception (group=0x4001d800) 11-21 14:33:05.166: E/AndroidRuntime(495): FATAL EXCEPTION: main 11-21 14:33:05.166: E/AndroidRuntime(495): java.lang.NullPointerException 11-21 14:33:05.166: E/AndroidRuntime(495): at com.workspace.multi.MultiActivity$1.onClick(MultiActivity.java:51) 11-21 14:33:05.166: E/AndroidRuntime(495): at com.android.internal.app.AlertController$AlertParams$4.onItemClick(AlertController.java:886) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.widget.AdapterView.performItemClick(AdapterView.java:284) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.widget.ListView.performItemClick(ListView.java:3382) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.widget.AbsListView$PerformClick.run(AbsListView.java:1696) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.os.Handler.handleCallback(Handler.java:587) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.os.Handler.dispatchMessage(Handler.java:92) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.os.Looper.loop(Looper.java:123) 11-21 14:33:05.166: E/AndroidRuntime(495): at android.app.ActivityThread.main(ActivityThread.java:4627) 11-21 14:33:05.166: E/AndroidRuntime(495): at java.lang.reflect.Method.invokeNative(Native Method) 11-21 14:33:05.166: E/AndroidRuntime(495): at java.lang.reflect.Method.invoke(Method.java:521) 11-21 14:33:05.166: E/AndroidRuntime(495): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868) 11-21 14:33:05.166: E/AndroidRuntime(495): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626) 11-21 14:33:05.166: E/AndroidRuntime(495): at dalvik.system.NativeStart.main(Native Method)

4

1 回答 1

3

检查这个...

 ArrayList<Integer> pos=new ArrayList<Integer>();
final CharSequence str[]={"Android","Black Berry","Iphone"};
    private void MultipleChoiceSpinner() {
        // TODO Auto-generated method stub


        AlertDialog.Builder builder=new AlertDialog.Builder(TestGalleryActivity.this).setMultiChoiceItems(str, default_selected, new  DialogInterface.OnMultiChoiceClickListener()
        {

            @Override
            public void onClick(DialogInterface dialog, int which, boolean isChecked) 
            {
            if(isChecked)
            {
                pos.add(which);
                default_selected[which]=true;
            }
                else{
                    pos.remove(pos.indexOf(which));
                    default_selected[which]=false;
                }


            }
        }).setTitle("Select Any");
        builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {

            @Override
            public void onClick(DialogInterface dialog, int which) {
                Toast.makeText(TestGalleryActivity.this, "Selected positions:"+pos.toString(), Toast.LENGTH_SHORT).show();
            }
        });
        d=builder.create();
        d.show();

    }

嗨，我只是在这里添加两种类型的警报框。我希望它对某人有用。

于 2011-11-21T07:31:27.207 回答