从列表视图中检索数据并将其显示在 textview/imageview 中

Question

我已经对此进行了研究，但没有任何内容符合我的要求。我有一个食谱类型列表，如果我单击其中一个类别（开胃菜），它会将我带到另一个列表：一个包含开胃菜列表的列表视图。如果我单击列表中的其中一项，它应该会带我到一个 activity，其中有图像、标题、标题下方的烹饪时间以及图像和文本视图下方的食谱本身。

编辑以显示查询解析的代码：

ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Appetizers");
    query.addAscendingOrder("appetizer");
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> recipes, ParseException e) {
            if (e == null) {
                // success        
            } else {
                // error

            }

我该怎么做？

开胃菜列表：

Activity:

编辑：

开胃菜适配器：

public class AppetizerAdapter extends ArrayAdapter {

protected Context myContext;
protected List myAppetizer;

public AppetizerAdapter(Context context, List myappetizer) {
    super(context, R.layout.custom_appetizer, myappetizer);

    myContext = context;
    myAppetizer = myappetizer;
}

// inflates each row of the app
@Override
public View getView(final int position, View convertView, ViewGroup parent) {

    // initialize viewholder
    ViewHolder holder;

    if (convertView == null) { // If no items in the view to be displayed
        convertView = LayoutInflater.from(myContext).inflate(
                R.layout.custom_appetizer, null);

        // initialize the views
        holder = new ViewHolder(); // creates a new view
        holder.appetizerTextView = (TextView) convertView // calls the view
                .findViewById(R.id.appetizer);
        holder.appetizerImageView = (ImageView) convertView.findViewById(R.id.appetizerImage);
        holder.cookTimeTextView = (TextView) convertView.findViewById(R.id.cookTime);

        // call the view and setTag to the parameter (holder)
        convertView.setTag(holder);

    } else { // if view is previously displayed

        // initialize holder
        holder = (ViewHolder) convertView.getTag();

    }

    // get the position of the row
    ParseObject appObject = (ParseObject) myAppetizer.get(position);

    // Title and Cook Time
    String app = appObject.getString("appetizer"); // column passing
    holder.appetizerTextView.setText(app);

    String cook = appObject.getString("cookTime");
    holder.cookTimeTextView.setText(cook);

    // image
    Picasso.with(getContext()).load(appObject.getParseFile("imageFiles").getUrl())
            .into(holder.appetizerImageView);

    return convertView; // return the view
}

public static class ViewHolder {

    // declaration of variables
    TextView appetizerTextView;
    TextView cookTimeTextView;
    ImageView appetizerImageView;

}

}

Appetizer.java

public class Appetizer extends ListActivity {

protected List<ParseObject> mAppetizers;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_appetizer);

    ParseAnalytics.trackAppOpenedInBackground(getIntent());

    ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Appetizers");
    query.addAscendingOrder("appetizer");
    query.findInBackground(new FindCallback<ParseObject>() {
        @Override
        public void done(List<ParseObject> appetizer, ParseException e) {
            if (e == null) {
                // success
                mAppetizers = appetizer;

                AppetizerAdapter adapter = new AppetizerAdapter(getListView().getContext(),
                        mAppetizers);
                setListAdapter(adapter);

            } else {

                // there is a problem
                AlertDialog.Builder builder = new AlertDialog.Builder(Appetizer.this);
                builder.setMessage(e.getMessage());
                builder.setTitle("Sorry");
                builder.setPositiveButton("OK", new DialogInterface.OnClickListener() {
                    @Override
                    public void onClick(DialogInterface dialog, int which) {
                        // close the dialog
                        dialog.dismiss();
                    }
                });

                AlertDialog dialog = builder.create();
                dialog.show();
            }
        }
    });



}

@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_directory, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

// click on a row item
@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);



    Intent intent = new Intent(Appetizer.this, AppetizerRecipe.class);
    startActivity(intent);
}

}

我有一个名为 content_appetizer_recipe 的布局，其中包含图片中的布局和图像，以及 3 个文本视图（不是列表）。 AppetizerRecipe 是一个 AppCompatActivity.

希望这有助于解决我的问题。

Answer 1

假设你有一个 Recipe class 和一些 ArrayAdapter<Recipe> 实现，你应该能够遍历 Parse returns 给你的值列表并使用从 ParseObject 中提取值的适当方法。

ArrayAdapter 负责在 TextView 和 ImageView 中显示正确的数据。

ListView lv = (ListView) findViewById(R.id.listView); // TODO
List<Recipe> recipeList = new ArrayList<Recipe>();
final RecipeAdapter adapter = new RecipeAdapter(RecipeActivity.this, recipeList);
lv.setAdapter(adapter);

ParseQuery<ParseObject> query = new ParseQuery<ParseObject>("Appetizers");
query.addAscendingOrder("appetizer");
query.findInBackground(new FindCallback<ParseObject>() {
    @Override
    public void done(List<ParseObject> recipes, ParseException e) {
        if (e == null) {
            for (ParseObject po : recipes) {
                Recipe r = new Recipe();

                // TODO: Retrieve fields from the ParseObject 
                r.setName(po.get...);
                r.setTime(po.get...);
                r.setImageUrl(po.get...);

                adapter.add(r);
            }
        } else {
            // error
        }
});

如果你没有这个Recipe class，那么就像你所做的那样将List<ParseObject>加载到适配器中，然后在onListItemClick方法中，你可以使用 position 参数从该列表中获取特定对象。

在这里，您还需要 AppetizerRecipe.java 中的 public static final String ARG_NAME = "name"; 字段以保持您的论点一致。您可以参考 Passing data between Activities 了解更多信息。您还需要从 AppetizerRecipe.java 内的 Intent 中获取数据。

@Override
protected void onListItemClick(ListView l, View v, int position, long id) {
    super.onListItemClick(l, v, position, id);

    ParseObject po = mAppetizers.get(position);
    String name = po.getString("appetizer");
    // TODO: Get more fields from Parse

    Intent intent = new Intent(Appetizer.this, AppetizerRecipe.class);
    intent.putExtra(AppetizerRecipe.ARG_NAME, name);
    // TODO: Put more extras

    startActivity(intent); // TODO: In other activity, get these extras
}

从列表视图中检索数据并将其显示在 textview/imageview 中

Retrieving data from a listview and displaying it in a textview/imageview

android

parse-platform

parse-server