Question

我在android中制作了自定义列表视图。我希望每当列表视图点击事件被调用它进入另一个活动，该列表上的数据将显示在新活动上。下面的代码是我喜欢的MainActivity（这里命名为ListofWorkers），它也有布局文件。

package com.example.dispatchmedemo;

import android.os.Bundle;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.view.Menu;

import java.util.ArrayList;
import java.util.List;
import android.view.Gravity;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.Button;
import android.widget.ListView;
import android.widget.Toast;
import com.example.dispatchmedemo.CustomListViewAdapter;
import com.example.dispatchmedemo.RowItem;

public class ListofWorkers extends Activity {

    public static final String[] name = new String[] { "ABC",
            "YZA", "ASDSA", "ASD", "ASD", "SDFS" };

    public static final String[] landmarks = new String[] {
            "AFDDF",
            "ADF", "ADFD",
            "ADFAD", "ADFADF", "ADFAD" };

    public static final String[] rates = new String[] {
        "100",
        "500", "300",
        "400", "120", "600" };

    public static final Integer[] images = { R.drawable.ic_launcher,
            R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher };

    ListView listView;
    List<RowItem> rowItems;
    Button responseSubmit;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_listof_workers);

        rowItems = new ArrayList<RowItem>();
        for (int i = 0; i < name.length; i++) {
            RowItem item = new RowItem(images[i], name[i], landmarks[i], rates[i]);
            rowItems.add(item);
        }

        listView = (ListView) findViewById(R.id.list);
        CustomListViewAdapter adapter = new CustomListViewAdapter(this,
                R.layout.list_single, rowItems);
        listView.setAdapter(adapter);


        listView.setOnItemClickListener(new OnItemClickListener() {

            @Override
            public void onItemClick(AdapterView<?> parent, 
                    View view,int position, long id) {

                Intent i = new Intent(ListofWorkers.this, WorkerProfile.class);

                i.putExtra("name", name);

                i.putExtra("landmarks", landmarks);

                i.putExtra("rates", rates);

                i.putExtra("image", images);

                i.putExtra("position", position);

                startActivity(i);
              }

        });
    }
    }

现在这是我的另一项活动＆＃34; WorkerProfile＆＃34;我得到了名字，地标和费率，但只有在图像中，我得到了空指针异常，我把它放在TOAST中。

package com.example.dispatchmedemo;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

public class WorkerProfile extends Activity {
    // Declare Variables
    TextView txtname;
    TextView txtlandmark;
    TextView txtrate;
    ImageView imgpro;
    String[] name;
    String[] landmarks;
    String[] rate;
    int[] images;
    int position;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_worker_profile);

        Intent i = getIntent();

        position = i.getExtras().getInt("position");

        name = i.getStringArrayExtra("name");

        landmarks = i.getStringArrayExtra("landmarks");

        rate = i.getStringArrayExtra("rates");

        images  = i.getIntArrayExtra("image");


        txtname = (TextView) findViewById(R.id.textView1);
        txtlandmark = (TextView) findViewById(R.id.textView2);
        txtrate = (TextView) findViewById(R.id.textView3);

        imgpro = (ImageView)findViewById(R.id.ActivityWorkerProflePic);


        txtname.setText(name[position]);
        txtlandmark.setText(landmarks[position]);
        txtrate.setText(rate[position]);

        imgpro.setImageResource(images[position]);
       }
}

Answer 1

这里传递整数作为整数定义的对象，这是一个包装类。

在接收器活动中，您将其检索为基本类型数组（ int ）。这就是你得到Null指针异常的原因。

请更改以下代码，

public static final Integer[] images = { R.drawable.ic_launcher,
            R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher };

要，

public static final int[] images = { R.drawable.ic_launcher,
            R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher, R.drawable.ic_launcher };

希望它会有所帮助。

Answer 2

尝试这样的事情：

Bundle bundel = new Bundle();
bundel.putIntArray("image",images);

Intent intent = new Intent(this,next.class)
intent.putExtras(bundel);
startActivity(intent);

并在next.class中使用如下：

Integer img[] = getIntent().getExtras().getIntArray("image");

Answer 3

试试这个..

将图像数组作为IntegerArrayList放入发送意图

i.putIntegerArrayListExtra("image", new ArrayList<Integer>(Arrays.asList(images)))

然后得到像

ArrayList<Integer> images  = i.getIntegerArrayListExtra("image");

使用它

imgpro.setImageResource(images.get(position));

从android中的另一个活动获取图像时获取空指针异常

3 个答案: