如何在自动完成文本视图中显示建议下拉列表

Question

我想在文本字段为空时向用户显示所有建议，我从 json 响应中获取我的建议，当用户键入它出现在下拉列表中的单词但当文本字段为空时它不显示任何内容甚至尝试过showDropDown() 但Android Monitor 说：尝试完成输入事件但输入事件接收器已被释放。

这是我的代码：

public class MainActivity extends AppCompatActivity {
AutoCompleteTextView acTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    acTextView = (AutoCompleteTextView) findViewById(R.id.autoComplete);
    acTextView.setAdapter(new SuggestionAdapter(this,acTextView.getText().toString()));
    acTextView.setThreshold(0);

    acTextView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            acTextView.showDropDown();
        }
    });
        }
    });
  }
}

我首先从这些课程中获得我的建议适配器 JSON Parser 从 URL 中解析关键字。 getter setter 类。 Suggestions Adapter 在适配器中设置过滤的项目。 我的 JSON 响应：

 [{"lookupValueId":350,"lookupTypeId":33,"lookupValue":"Java"},{"lookupValueId":351,"lookupTypeId":33,"lookupValue":"C++"},{"lookupValueId":352,"lookupTypeId":33,"lookupValue":"Photoshop"},{"lookupValueId":353,"lookupTypeId":33,"lookupValue":"Java Script"}]

JSON 解析器类：

public class JsonParse {


public List<SuggestGetSet> getParseJsonWCF(String sName)
{
    List<SuggestGetSet> ListData = new ArrayList<SuggestGetSet>();
    try {
        String temp = sName.replace(" ", "%20");
        URL js = new URL("http://SomeUrl" + temp + "%22%7D%7D");
                    URLConnection jc = js.openConnection();
        BufferedReader reader = new BufferedReader(new InputStreamReader(jc.getInputStream()));
        String line = reader.readLine();
        JSONArray jsonResponse = new JSONArray(line);
        System.out.print("DATA: " + line);
        for(int i = 0; i < jsonResponse.length(); i++){
            JSONObject r = jsonResponse.getJSONObject(i);
            ListData.add(new SuggestGetSet(r.getInt("lookupValueId"),r.getString("lookupValue")));
        }
    } catch (Exception e1) {
        e1.printStackTrace();
    }
    return ListData;

   }
}

getter setter 类：

public class SuggestGetSet {
String name;
static Integer id;
public SuggestGetSet(int id, String name){
    this.setId(id);
    this.setName(name);
}
public static Integer getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}

public String getName() {
    return name;
}

public void setName(String name) {
    this.name = name;
  }
}

最后是适配器类：

class SuggestionAdapter extends ArrayAdapter<String> {

private List<String> suggestions;

SuggestionAdapter(Activity context,String nameFilter) {
    super(context, android.R.layout.simple_dropdown_item_1line);
    suggestions = new ArrayList<>();
}


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

@Override
public String getItem(int index) {
    return suggestions.get(index);
}

@NonNull
@Override
public Filter getFilter() {
    return new Filter() {
        @Override
        protected FilterResults performFiltering(CharSequence constraint) {
            FilterResults filterResults = new FilterResults();
            JsonParse jp = new JsonParse();
            if (constraint != null) {
                // A class that queries a web API, parses the data and
                // returns an ArrayList<GoEuroGetSet>
                List<SuggestGetSet> new_suggestions = jp.getParseJsonWCF(constraint.toString());
                suggestions.clear();
                for (int i = 0; i < new_suggestions.size(); i++) {
                    suggestions.add(new_suggestions.get(i).getName());
                }

                // Now assign the values and count to the FilterResults
                // object
                filterResults.values = suggestions;
                filterResults.count = suggestions.size();
            }
            return filterResults;
        }

        @Override
        protected void publishResults(CharSequence constraint,
                                      FilterResults results) {
            if (results != null && results.count > 0) {
                notifyDataSetChanged();
            } else {
                notifyDataSetInvalidated();
            }
        }
    };
  }
}

我关注了这个参考：http://manishkpr.webheavens.com/android-autocompletetextview-example-json/

Answer 1

首先获取响应并将 arraylist 从活动传递到您的适配器。 你的代码

acTextView.setAdapter(new SuggestionAdapter(this,yourarraylist));

Answer 2

首先，如果 android 为您提供相同的组件，为什么您需要自定义适配器

关注tutorial和this

建议如 geeta 所说，首先从 JSON 创建 ArrayList，而不是将其传递给 adpter，这是最好的方法

希望对你有帮助