Question

我是Android的新手，我想给我的列表活动的每个项目一个不同的图标，所以我该怎么做...这是我的列表活动与不同的项目

public class MenuAct extends ListActivity {
  @Override
public void onCreate(Bundle icicle) {
    super.onCreate(icicle);
   String[] values = new String[] { 
            "Mes Missions",
            "Mes Points",
            "Importer Geotiff",
            "Importer Point KML",
            "Importer Zone KML",
            "Exporter" };
    // use your custom layout
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(this,
        R.layout.menu_activity, R.id.label, values);
    setListAdapter(adapter);
  }

Answer 1

您想创建自己的ListAdapter，然后修改它以设置图像。

查看http://www.javacodegeeks.com/2013/06/android-listview-custom-adapter-with-imageview.html以获取示例。

Answer 2

适配器负责创建与每个项目关联的视图。在这种情况下，您将使用ArrayAdapter为每个项目返回一个视图，该视图包含（或多或少）单个TextView，并且每行都对应一个字符串。

您需要做的是创建一个自定义适配器（派生自BaseAdapter），返回更复杂的视图（特别是包括您想要的ImageView）。

这是一个很好的示例：http://www.vogella.com/tutorials/AndroidListView/article.html#adapterown_custom

Answer 3

您必须创建自定义适配器。在你将覆盖的适配器的getView（）方法中，你可以轻松地在每个项目上放置你想要的任何图标。

你可以这样做：

someListView.setAdapter(new ImageAdapter(mContext));

然后，如果你将数据保存在ArrayList或类似的（我称之为我的pathListThumbs），请像这样定义ImageAdapter：

  public class ImageAdapter extends BaseAdapter {
    private Context mContext;

    public ImageAdapter(Context c) {
        mContext = c;
    }

    public int getCount() {
        return pathListThumbs.size();
    }

    public Object getItem(int position) {
        return null;
    }

    public long getItemId(int position) {
        return 0;
    }

    // create a new ImageView for each item referenced by the Adapter
    public View getView(final int position, View convertView, final ViewGroup parent) {

查看itemView = convertView; if（gridView == null）{//如果它没有被回收，则初始化一些属性 //从xml获取布局 LayoutInflater inflater =（LayoutInflater）mContext.getSystemService（Context.LAYOUT_INFLATER_SERVICE）; itemView = inflater.inflate（R.layout.mylistviewitem，null）; }

        final GridProductHolder holder;

        if (gridView.getTag() != null) {
            holder = (GridProductHolder) gridView.getTag();
        } else {
            holder = new GridProductHolder();
            gridView.setTag(holder);
            holder.thumbNail = (ImageView) gridView.findViewById(R.id.thumbnail);
        }
        Bitmap bitmap = pathListThumbs.get(position), wScale, hScale);


        if (bitmap != null) {
            holder.thumbNail.setImageBitmap(bitmap);
        }

    }
}

Answer 4

好的，这是我用来将相机图像尺寸调整到所需x / y值的片段：

if (requestCode == REQUEST_FROM_CAMERA && resultCode == RESULT_OK) {

        _bitmapPreScale = gradeBookDbAdapter.getStudentPhoto(studentName);
    }
    if (_bitmapPreScale != null) {

            int oldWidth = _bitmapPreScale.getWidth();
            int oldHeight = _bitmapPreScale.getHeight();
            int newWidth = 200;  // whatever your desired width and height are
            int newHeight = 200;

            // calculate the scale
            float scaleWidth = ((float) newWidth) / oldWidth;
            float scaleHeight = ((float) newHeight) / oldHeight;

            // create a matrix for the manipulation
            Matrix matrix = new Matrix();
            // resize the bit map
            matrix.postScale(scaleWidth, scaleHeight);

            // recreate the new Bitmap
            Bitmap _bitmapScaled = Bitmap.createBitmap(_bitmapPreScale, 0, 0,  oldWidth, oldHeight, matrix, true);


            // write the image back out so it's always small

            try {
                   FileOutputStream out = new FileOutputStream(imgFile);
                   _bitmapScaled.compress(Bitmap.CompressFormat.JPEG, 50, out);
                   out.flush();
                   out.close();

            } catch (Exception e) {
                 Toast.makeText(mContext,"ERROR writing new image. Please try again",Toast.LENGTH_SHORT).show();
                 Log.e("STUDENT", "ERROR WRITING");
                   e.printStackTrace();
            }
        }
        else {
             Toast.makeText(mContext,"ERROR reading image. Please try again",Toast.LENGTH_SHORT).show();
             Log.e("STUDENT","ERROR READING");
        }

Answer 5

扩展BaseAdapter，编写自己的adpter

覆盖getView，因此您也可以设置图像

适配器代码的getView应该是（未经测试）

@Override
public View getView(int index, View convertView, ViewGroup parent)
{
    if (convertView == null)
        convertView = mInflater.inflate(R.layout.menu_activity, parent, false);

    TextView label = convertView.findViewById(R.id.label);

    label.setText(values[index]);

    Drawable icon = // obtain your image
    label.setCompoundDrawablesWithIntrinsicBounds(icon, null, null, null);
    return convertView;     
}

如何在列表活动中为每个项目提供不同的图标

5 个答案: