Question

我一直在尝试从另一个类调用Main Activity上的方法。但是，方法没有解决。看看代码。

package com.example.android.andhive_glideimagelib.activity;

import android.app.ProgressDialog;
import android.media.Image;
import android.os.Bundle;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.util.Log;
import android.view.View;

import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.JsonArrayRequest;
import com.example.android.andhive_glideimagelib.R;
import com.example.android.andhive_glideimagelib.adapter.GalleryAdapter;
import com.example.android.andhive_glideimagelib.app.AppController;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;

import java.util.ArrayList;

public class MainActivity extends AppCompatActivity {

    private String TAG = MainActivity.class.getSimpleName();
    private static final String endpoint = "http://api.androidhive.info/json/glide.json";
    private ArrayList<Image> images;
    private ProgressDialog pDialog;
    private GalleryAdapter mAdapter;
    private RecyclerView recyclerView;

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

        Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);

        pDialog = new ProgressDialog(this);
        images = new ArrayList<>();
        mAdapter = new GalleryAdapter(getApplicationContext(), images);

        RecyclerView.LayoutManager mLayoutManager = new GridLayoutManager(getApplicationContext(), 2);
        recyclerView.setLayoutManager(mLayoutManager);
        recyclerView.setItemAnimator(new DefaultItemAnimator());
        recyclerView.setAdapter(mAdapter);

         recyclerView.addOnItemTouchListener(new GalleryAdapter.RecyclerTouchListener(getApplicationContext(), recyclerView, new GalleryAdapter.ClickListener() {
            @Override
            public void onClick(View view, int position) {
                Bundle bundle = new Bundle();
                bundle.putSerializable("images", images);
                bundle.putInt("position", position);

                FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
                SlideshowDialogFragment newFragment = SlideshowDialogFragment.newInstance();
                newFragment.setArguments(bundle);
                newFragment.show(ft, "slideshow");
            }

            @Override
            public void onLongClick(View view, int position) {

            }
        }));

        fetchImages();
    }

    private void fetchImages() {

        pDialog.setMessage("Downloading json...");
        pDialog.show();

        JsonArrayRequest req = new JsonArrayRequest(endpoint,
                new Response.Listener<JSONArray>() {
                    @Override
                    public void onResponse(JSONArray response) {
                        Log.d(TAG, response.toString());
                        pDialog.hide();

                        images.clear();
                        for (int i = 0; i < response.length(); i++) {
                            try {
                                JSONObject object = response.getJSONObject(i);
                                Image image = new Image();
                                image.setName(object.getString("name"));

                                JSONObject url = object.getJSONObject("url");
                                image.setSmall(url.getString("small"));
                                image.setMedium(url.getString("medium"));
                                image.setLarge(url.getString("large"));
                                image.setTimestamp(object.getString("timestamp"));

                                images.add(image);

                            } catch (JSONException e) {
                                Log.e(TAG, "Json parsing error: " + e.getMessage());
                            }
                        }

                        mAdapter.notifyDataSetChanged();
                    }
                }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Log.e(TAG, "Error: " + error.getMessage());
                pDialog.hide();
            }
        });

        // Adding request to request queue
        AppController.getInstance().addToRequestQueue(req);
    }
}

班级，

package com.example.android.andhive_glideimagelib.model;

import java.io.Serializable;

public class Image implements Serializable {
    private String name;
    private String small, medium, large;
    private String timestamp;

    public Image() {
    }

    public Image(String name, String small, String medium, String large, String timestamp) {
        this.name = name;
        this.small = small;
        this.medium = medium;
        this.large = large;
        this.timestamp = timestamp;
    }

    public String getName() {
        return name;
    }

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

    public String getSmall() {
        return small;
    }

    public void setSmall(String small) {
        this.small = small;
    }

    public String getMedium() {
        return medium;
    }

    public void setMedium(String medium) {
        this.medium = medium;
    }

    public String getLarge() {
        return large;
    }

    public void setLarge(String large) {
        this.large = large;
    }

    public String getTimestamp() {
        return timestamp;
    }

    public void setTimestamp(String timestamp) {
        this.timestamp = timestamp;
    }
}

我无法调用Image类的方法。谢谢您的帮助！

Answer 1

在图像类中使其成为静态方法例如：

public static void setSmall（String small）{

this.small =小; }

MainActivity中的

Image.setSmall（＆＃34;值＆＃34）;

来自另一个类的回调

1 个答案: