我在将数组传递到listview时遇到问题 我可以将图像传递给第二个活动但是当我 尝试将数组传递给listview我得到一个lang.NullPointerException错误 和应用程序崩溃。
任何有用的输入都会很棒谢谢
这是代码 主要活动
Pin to Start第二个活动我想将数组传递给
package com.example.androidlistview;
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ListView;
public class MainActivity extends Activity {
ListView listView;
// Defined the text values to show in ListView
String[] values = new String[]{"Barack Obama","Donald Trump","Bill Clinton",
"Hillary Clinton","Joe Biden"};
// Defined the image ids to show in ListView
Integer[] images = {
R.drawable.image1,R.drawable.image2,R.drawable.image3,R.drawable.image4,
R.drawable.image5
};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// create the custom view
CustomView adapter = new CustomView(MainActivity.this, values, images);
// Get ListView object from xml
listView = (ListView) findViewById(R.id.container);
//set adapter
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,int position, long id) {
if(position == 0){
Intent contact = new Intent(MainActivity.this, Details.class);
String[] details= new String[]{"Barack Obama","The White House","1-234-567-8900",
"Barack.Obama@whitehouse.com","note"};
Integer image = images[0];
contact.putExtra("image", image);
contact.putExtra("details", details);
startActivity(contact);
}
if(position == 1){
Intent contact = new Intent(MainActivity.this, Details.class);
String[] details= new String[] {"Donald Trump","Trump Tower","1-234-567-8901",
"Donald.Trump@whitehouse.com","note"};
Integer image = images[1];
contact.putExtra("image", image);
contact.putExtra("details", details);
startActivity(contact);
}
if(position == 2){
Intent contact = new Intent(MainActivity.this, Details.class);
String[] details = new String[] {"Bill Clinton","New York","1-234-567-8902",
"Bill.Clinton@whitehouse.com","note"};
Integer image = images[2];
contact.putExtra("image", image);
contact.putExtra("details", details);
startActivity(contact);
}
if(position == 3){
Intent contact = new Intent(MainActivity.this, Details.class);
String[] details = new String[] {"Hillary Clinton","New Jersey","1-234-567-8903",
"Hillary.Clinton@whitehouse.com","note"};
Integer image = images[3];
contact.putExtra("image", image);
contact.putExtra("details", details);
startActivity(contact);
}
if(position == 4){
Intent contact = new Intent(MainActivity.this, Details.class);
String[] details= new String[] {"Joe Biden","OHIO","1-234-567-8903",
"Joe.Biden@whitehouse.com","note"};
Integer image = images[4];
contact.putExtra("image", image);
contact.putExtra("details", details);
startActivity(contact);
}
}
});
}
}
以及我用于第二个活动详细信息的自定义视图
package com.example.androidlistview;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
import android.widget.Toast;
public class Details extends Activity {
ListView list;
String []web={"Name:","Address:","Phone Number:","Email:","Note:"};
int image;
String[] details;
TextView textView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_details);
// create the custom view
CustomList Adapter= new CustomList(Details.this, web, details);//, details should go here
// Get ListView object from xml
list=(ListView)findViewById(R.id.list);
//set adapter
list.setAdapter(Adapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener(){
@Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
}
});
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
image= bundle.getInt("image");
ImageView imageView = (ImageView) findViewById(R.id.imageView1);
imageView.setImageResource(image);
}
}
}
答案 0 :(得分：0)
这就是我为解决这个问题而采取的措施 主要活动
package com.example.androidcontacts;
import android.app.ListActivity;
import android.content.CursorLoader;
import android.content.Intent;
import android.database.Cursor;
import android.net.Uri;
import android.os.Bundle;
import android.support.v4.widget.CursorAdapter;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.SimpleCursorAdapter;
public class MainActivity extends ListActivity {
ListView mylist;
SearchView searchView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Uri allContacts = Uri.parse("content://"+"com.example.androidcontacts.Books" + "/Contact");
Cursor c;
CursorLoader cursorLoader = new CursorLoader(
this,allContacts,null,null,null,null);
c = cursorLoader.loadInBackground();
String[] columns = new String[] {Contact._ID,Contact.TITLE,Contact.AUTHOR,Contact.YEAR,Contact.IMAGE};
int[] views = new int[] {R.id.contactID,R.id.contactName,R.id.contactAuthor,R.id.contactYear,R.id.Image};
SimpleCursorAdapter adapter;
adapter = new SimpleCursorAdapter(this, R.layout.activity_main,
c, columns, views,CursorAdapter.FLAG_REGISTER_CONTENT_OBSERVER);
this.setListAdapter(adapter);
}
@Override
protected void onListItemClick(ListView list, View view, int position, long id) {
//Intent i=new Intent(MainActivity.this,Details.class);
//startActivity(i);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item){
int id = item.getItemId();
if(id == R.id.action_search){
Intent intent = new Intent(this, Search.class);
startActivity(intent);
finish();
return true;
}
if(id == R.id.action_add){
Intent intent = new Intent(this, Add.class);
startActivity(intent);
finish();
return true;
}
return super.onOptionsItemSelected(item);
}
}
第二项活动详情
package com.example.androidlistview;
import android.app.Activity;
import android.content.Intent;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
public class Details extends Activity {
//Variables for Bundle
int image;
String name;
String address;
String phone;
String email;
String note;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_details);
Button SMS = (Button) findViewById(R.id.button1);
SMS.setOnClickListener(new OnClickListener() {
//when button1 is clicked open messenger
@Override
public void onClick(View v) {
startActivity(new Intent(Intent.ACTION_VIEW, Uri.fromParts("sms", phone, null)));
}
});
Button Email = (Button) findViewById(R.id.button2);
Email.setOnClickListener(new OnClickListener() {
//when button2 is clicked open email
@Override
public void onClick(View v) {
Intent emailIntent = new Intent(Intent.ACTION_SENDTO, Uri.parse("mailto:"));
emailIntent.putExtra(Intent.EXTRA_EMAIL, new String[] { email });
startActivity(Intent.createChooser(emailIntent, "Choose Email Client"));
}
});
Button Phone = (Button) findViewById(R.id.button3);
Phone.setOnClickListener(new OnClickListener() {
//when button3 is clicked start call
@Override
public void onClick(View v) {
startActivity(new Intent(Intent.ACTION_DIAL, Uri.fromParts("tel", phone, null)));
}
});
// get details passed from MainActivity
Bundle bundle = getIntent().getExtras();
if (bundle != null) {
image= bundle.getInt("image");
ImageView imageView = (ImageView) findViewById(R.id.imageView1);
imageView.setImageResource(image);
name = bundle.getString("name");
TextView nameView = (TextView) findViewById(R.id.name1);
nameView.setText(name);
address = bundle.getString("address");
TextView addressView = (TextView) findViewById(R.id.address1);
addressView.setText(address);
phone = bundle.getString("phone");
TextView phoneView = (TextView) findViewById(R.id.phone1);
phoneView.setText(phone);
email = bundle.getString("email");
TextView emailView = (TextView) findViewById(R.id.email1);
emailView.setText(email);
note = bundle.getString("note");
TextView noteView = (TextView) findViewById(R.id.note1);
noteView.setText(note);
}
}
}
我的自定义视图
package com.example.androidlistview;
import android.app.Activity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class CustomView extends ArrayAdapter<String>{
private final Activity context;
private final String[] values;
private final Integer[] images;
//Constructor
public CustomView(Activity context,String[] values, Integer[] images) {
super(context, R.layout.single_row, values);
this.context = context;
this.values = values;
this.images = images;
}
@Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView= inflater.inflate(R.layout.single_row, null, true);
TextView txtTitle = (TextView) rowView.findViewById(R.id.txt);
txtTitle.setText(values[position]);
ImageView imageView = (ImageView) rowView.findViewById(R.id.img);
imageView.setImageResource(images[position]);
return rowView;
}
}