Question

我正在创建一个简单的应用程序，以便在Android的网格视图中共享图像。我创建了一个数组但是当我尝试创建这些图像的gridview时，我的代码出错了，我无法解决。

这是我的代码：

 public class ImageAdapter extends BaseAdapter
 {
private Context context;

public ImageAdapter(Context arg2)
{
  Object localObject;

  this.context = localObject;

    }
    public int getCount()
    {
      return MainActivity.this.mThumbIds.length;
    }

    public Object getItem(int paramInt)
    {
      return Integer.valueOf(paramInt);
    }

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

    public View getView(int paramInt, View paramView, ViewGroup paramViewGroup)
    {
      if (paramView != null)
      {
        MainActivity.this.imageView = ((ImageView)paramView);
      }
      else
      {
        MainActivity.this.imageView = new ImageView(this.context);
        MainActivity.this.imageView.setLayoutParams(new AbsListView.LayoutParams(90, 90));
        MainActivity.this.imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
        MainActivity.this.imageView.setPadding(5, 5, 5, 5);
      }
      MainActivity.this.imageView.setImageResource(MainActivity.this.mThumbIds[paramInt].intValue());
      return MainActivity.this.imageView;
    }
  }
}

我在这里收到错误：Type mismatch error: Cannot convert Object to Content错误指向localObject

Answer 1

你没有使用arg2吗？

无论如何，尝试实际上对变量进行类型转换： this.context = (Context) localObject;

Answer 2

~~Object localObject;~~

Context context;
public ImageAdapter(Context arg2)
{
    this.context = arg2;
}

而不是MainActivity.this.imageView使用imageView（这不是错误）

在必要时也使用@Override。

Answer 3

您将像这样使用您的基本适配器并更新您的网格视图，如下面的代码..

public class GridViewImageAdapter extends BaseAdapter {

private Activity activity;
private ArrayList<String> filePaths = new ArrayList<String>();
private int imageWidth;

public GridViewImageAdapter(Activity activity,
        ArrayList<String> imagePaths, int imageWidth) {
    this.activity = activity;
    this.filePaths = imagePaths;
    this.imageWidth = imageWidth;
}

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

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

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

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    ImageView imageView;
    if (convertView == null) {
        imageView = new ImageView(activity);
    } else {
        imageView = (ImageView) convertView;
    }

    // get screen dimensions
    Bitmap image = decodeFile(filePaths.get(position), imageWidth,
            imageWidth);
    imageView.setScaleType(ImageView.ScaleType.CENTER_CROP);
    imageView.setLayoutParams(new GridView.LayoutParams(imageWidth,
            imageWidth));
    imageView.setImageBitmap(image);
    return imageView;
}

public static Bitmap decodeFile(String filePath, int WIDTH, int HIGHT) {
    try {

        File f = new File(filePath);

        BitmapFactory.Options o = new BitmapFactory.Options();
        o.inJustDecodeBounds = true;
        BitmapFactory.decodeStream(new FileInputStream(f), null, o);

        final int REQUIRED_WIDTH = WIDTH;
        final int REQUIRED_HIGHT = HIGHT;
        int scale = 1;

        while (o.outWidth / scale / 2 >= REQUIRED_WIDTH
                && o.outHeight / scale / 2 >= REQUIRED_HIGHT) {
            scale *= 2;
        }

        BitmapFactory.Options o2 = new BitmapFactory.Options();
        o2.inSampleSize = scale;
        return BitmapFactory.decodeStream(new FileInputStream(f), null, o2);
    } catch (FileNotFoundException e) {
        e.printStackTrace();
    }
    return null;
}

}

将适配器值设置为GridView，Imagepaths我已将我的图像存储在SD卡中，所以只有我给适配器的路径...一切顺利

    gridView = (GridView) findViewById(R.id.gridView1);

    // loading all image paths from SD card
    imagePaths = utils.getFilePaths();

    // Gridview adapter
    adapter = new GridViewImageAdapter(GridViewActivity.this, imagePaths,columnWidth);

    // setting grid view adapter
    gridView.setAdapter(adapter);

Android错误：类型不匹配错误：无法将对象转换为内容

3 个答案: