点击客户姓名后,需要在谷歌地图上用标记标记他/她的位置。当我在弹出窗口上显示客户详细信息时,客户的纬度和经度通过 Intent 作为对象从弹出窗口类传递到 map Activity 类。在 map activity.java 中接收它时,它变为 null 并抛出空指针异常。
我的弹出窗口类代码(CustomerPupUp.java):
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_customer_pop_up);
DisplayMetrics dm = new DisplayMetrics();
getWindowManager().getDefaultDisplay().getMetrics(dm);
int width = dm.widthPixels;
int height = dm.heightPixels;
getWindow().setLayout((int)(width),(int)(height*.7));
listView = (ListView)findViewById(R.id.custListVw);
database = FirebaseDatabase.getInstance();
reference = database.getReference("Customers");
list = new ArrayList<>();
adapter = new ArrayAdapter<String>(this, R.layout.activity_cust_layout,R.id.cus, list);
customer = new AddCustomer();
reference.addValueEventListener(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds: dataSnapshot.getChildren() )
{
customer = ds.getValue(AddCustomer.class);
Log.d("CustomerPopUp", "onDataChange: " + customer.getLat());
list.add(customer.getFname().toString() + " " + customer.getLname().toString() );
customerList.add(customer);
}
listView.setAdapter(adapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent intent = new Intent(CustomerPopUp.this, MapsActivity.class);
intent.putExtra("CustomerData", customerList.get(position));
startActivity(intent);
}
});
}
@Override
public void onCancelled(DatabaseError databaseError) {
}
});
}
以下代码段显示了我如何通过 MapsActivity.java 中的 Intent 获取对象
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_maps);
try {
database = FirebaseDatabase.getInstance();
reference = database.getReference("Customers");
customer= (AddCustomer) getIntent().getSerializableExtra("CustomerData");
mMap.addMarker(new MarkerOptions().position(new LatLng(customer.getLat(), customer.getLng())).title(customer.getFname() + customer.getLname()));
}catch (NullPointerException ex)
{
Log.d(TAG, "onCreate: " + ex.getMessage());
}
search = (EditText)findViewById(R.id.SearchText);
gps =(ImageView) findViewById(R.id.GpsBtn);
cust = (ImageView)findViewById(R.id.CusBtn);
isServiceFine();
getLocationPermission();
cust.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(MapsActivity.this, CustomerPopUp.class);
startActivity(intent);
}
});
}
下面是AddCustomer类
public class AddCustomer implements Serializable {
private String fname;
private String lname;
private String email;
private String pass;
private String confPass;
private int num;
Double lat;
Double lng;
AddCustomer()
{
}
public AddCustomer(String FName, String LName, String EMail, String PWD, String CONFPWD, int NUM, Double latitude, Double longtitude)
{
this.fname = FName;
this.lname = LName;
this.email = EMail;
this.pass = PWD;
this.confPass = CONFPWD;
this.num = NUM;
this.lat = latitude;
this.lng = longtitude;
}
public String getFname() {
return fname;
}
public void setFname(String fname) {
this.fname = fname;
}
public String getLname() {
return lname;
}
public void setLname(String lname) {
this.lname = lname;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPass() {
return pass;
}
public void setPass(String pass) {
this.pass = pass;
}
public String getConfPass() {
return confPass;
}
public void setConfPass(String confPass) {
this.confPass = confPass;
}
public int getNum() {
return num;
}
public void setNum(int num) {
this.num = num;
}
public Double getLat() {
return lat;
}
public void setLat(Double lat) {
this.lat = lat;
}
public Double getLng() {
return lng;
}
public void setLng(Double lng) {
this.lng = lng;
}
请帮我解决这个问题。
最佳答案
您只能通过Intent
传递Parcelable
或Serializable
对象。在这种情况下,对于您的自定义对象,您需要使其实现 Parcelable
或 Serializable
。
我推荐使用 http://www.parcelabler.com/轻松生成您的代码。
关于java - 为什么一个对象在传入 Intent 后变为空?,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/50110098/