Question

我正在使用图像切换器来显示多张图片。

我初始化了最终的Integer [] imageIDs = {}，并在位于OnCreate中的If-Else语句中使用了declare元素。我这样做是因为对于每个不同的地方，我想将不同的图片输入到imageID中。在这个例子中是“英国”。因此，如果选择了其他地方，则imageID应该有不同的图片参考。

不幸的是，当我运行应用程序时，imageswitcher中没有任何内容。

final Integer[] imageIDs = {};

private ImageSwitcher imageSwitcher;
DBAdapter dbAdapter;
final Context context = this;

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

    Intent intent = getIntent();
    String selectedSubArea = intent.getStringExtra("SelectedSubArea");

    Button btnAddToTrip = (Button) findViewById(R.id.btnAddToTrip);
    Button btnAddToFav = (Button) findViewById(R.id.btnAddToFav);
    Button btnShowAttractionLocation = (Button) findViewById(R.id.btnShowAttractionLocation);
    TextView description = (TextView) findViewById(R.id.description);
    TextView address = (TextView) findViewById(R.id.address);
    TextView openingHours = (TextView) findViewById(R.id.openingHours);
    TextView contactNo = (TextView) findViewById(R.id.contactNo);

    if (selectedSubArea.equals("UK"))
    {
        this.setTitle(selectedSubArea);
        description.setText("desc");
        address.setText("add");
        latitude = 2.0057378;
        longitude = 103.3760577;
        openingHours.setText("n/a");
        contactNo.setText("n/a");

        final Integer[] imageIDs = {
                R.drawable.uk_1,
                R.drawable.uk_2,
                R.drawable.uk_3};

        name = selectedSubArea;
        desc = description.toString();
        add = address.toString();
        opening = openingHours.toString();
        contact = contactNo.toString();

        dbAdapter = new DBAdapter(context);

        imageSwitcher = (ImageSwitcher) findViewById(R.id.switcher1);
        imageSwitcher.setFactory(this);
        imageSwitcher.setInAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_in));
        imageSwitcher.setOutAnimation(AnimationUtils.loadAnimation(this, android.R.anim.fade_out));
        Gallery gallery = (Gallery) findViewById(R.id.gallery1);
        gallery.setAdapter(new ImageAdapter(this));
        gallery.setOnItemClickListener(new OnItemClickListener()
        {
            public void onItemClick(AdapterView<?> parent, View v, int position, long id)
            {
                imageSwitcher.setImageResource(imageIDs[position]);
            }
        });
    }
}

public View makeView()
{
    ImageView imageView = new ImageView(this);
    imageView.setBackgroundColor(0x00000000);
    imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
    imageView.setLayoutParams(new ImageSwitcher.LayoutParams(LayoutParams.FILL_PARENT, LayoutParams.FILL_PARENT));
    return imageView;
}

public class ImageAdapter extends BaseAdapter
{
    private Context context;
    private int itemBackground;
    public ImageAdapter(Context c)
    {
        context = c;
        //---setting the style---
        TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
        itemBackground = a.getResourceId(
        R.styleable.Gallery1_android_galleryItemBackground, 0);
        a.recycle();
    }

    //---returns the number of images---
    public int getCount()
    {
        return imageIDs.length;
    }

    //---returns the ID of an item---
    public Object getItem(int position)
    {
        return position;
    }

    public long getItemId(int position)
    {
        return position;
    }

    //---returns an ImageView view---
    public View getView(int position, View convertView, ViewGroup parent)
    {
        ImageView imageView = new ImageView(context);
        imageView.setImageResource(imageIDs[position]);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
        imageView.setBackgroundResource(itemBackground);
        return imageView;
    }   
}

Answer 1

您的全局 imageIDs 数组长度为 ZERO ，因此无显示任何内容。在您的情况下，您无法使用最终数组，因为对象可能因 selectedSubArea

而异

<强>否则

您可以像这样更改 ImageAdapter ，然后它就能正常工作

public class ImageAdapter extends BaseAdapter
{
    private Context context;
    private int itemBackground;
    Integer[] local_imageIDs
    public ImageAdapter(Context c, Integer[] local_imageIDs)
    {
        context = c;
        this.local_imageIDs = local_imageIDs;
        //---setting the style---
        TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
        itemBackground = a.getResourceId(
        R.styleable.Gallery1_android_galleryItemBackground, 0);
        a.recycle();
    }

    //---returns the number of images---
    public int getCount()
    {
        return local_imageIDs.length;
    }

    //---returns the ID of an item---
    public Object getItem(int position)
    {
        return position;
    }

    public long getItemId(int position)
    {
        return position;
    }

    //---returns an ImageView view---
    public View getView(int position, View convertView, ViewGroup parent)
    {
        ImageView imageView = new ImageView(context);
        imageView.setImageResource(local_imageIDs[position]);
        imageView.setScaleType(ImageView.ScaleType.FIT_XY);
        imageView.setLayoutParams(new Gallery.LayoutParams(150, 120));
        imageView.setBackgroundResource(itemBackground);
        return imageView;
    }   
}

然后将此适配器设置为

gallery.setAdapter(new ImageAdapter(this, imageIDs));

删除全局 imageIDs

Android中的图像切换器问题

1 个答案: