如果有什么我正在努力解决这个问题，那么如何通过异步调用Firebase来编写外观漂亮的代码。以下是我的一个功能的代码，该功能从Firebase检索所有用户和当前用户，并检查他们所选位置之间的距离。
我无法将每个private void getUsersToDisplay() {
// Get users to display from firebase
Log.w(TAG, "User fetch initialized");
DatabaseReference currentUserRef = mDatabase.getReference().child("users/" + mCurrentUser.getUid());
// Get current user from firebase
currentUserRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot currentUserSnapshot) {
// Get the users chosen location for use in distance calculation
final Double currentUserChosenLatitude =
Double.parseDouble(currentUserSnapshot.child("chosen_location/latlng/latitude").getValue().toString());
final Double currentUserChosenLongitude =
Double.parseDouble(currentUserSnapshot.child("chosen_location/latlng/longitude").getValue().toString());
DatabaseReference usersRef = mDatabase.getReference().child("users");
// Get all users from firebase
usersRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot allUsersSnapshot) {
// For all users in firebase
for (DataSnapshot userSnap : allUsersSnapshot.getChildren()) {
String userId = userSnap.getKey();
DatabaseReference userRef = mDatabase.getReference().child("users/" + userId);
// If the user isn't the current user
if (!userId.equals(mCurrentUser.getUid())) {
// Get the user's info from firebase
userRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot userSnapshot) {
Double userChosenLatitude =
Double.parseDouble(userSnapshot.child("chosen_location/latlng/latitude").getValue().toString());
Double userChosenLongitude =
Double.parseDouble(userSnapshot.child("chosen_location/latlng/longitude").getValue().toString());
float[] results = new float[1];
Location.distanceBetween(
currentUserChosenLatitude,
currentUserChosenLongitude,
userChosenLatitude,
userChosenLongitude,
results);
// If the user is within 10km of the current user, display it
if (results[0] < 10000) {
users.put(userSnapshot.getKey(), (String) userSnapshot.child("first_name").getValue());
mUserAdapter.add((String) userSnapshot.child("first_name").getValue());
Log.w(TAG, "User to display fetch complete");
}
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.w(TAG, "User to display fetch cancelled");
}
});
}
}
Log.w(TAG, "Users fetch completed");
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.w(TAG, "Users fetch cancelled");
}
});
Log.w(TAG, "Current user fetch complete");
}
@Override
public void onCancelled(DatabaseError databaseError) {
Log.w(TAG, "Current user fetch cancelled");
}
});
}
移动到单独的函数中，因为它们都必须连续触发。
如何让这段代码看起来不错？
# BEGIN WordPress
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
RewriteRule ^scategory/(.*) http://www.truckeeriverrock.com/$1 [R=301,L]
RewriteRule ^whosonline/(.*) http://www.truckeeriverrock.com/$1 [R=301,L]
RewriteRule ^admintools/(.*) http://www.truckeeriverrock.com/$1 [R=301,L]]
</IfModule>
# END WordPress
答案 0 :(得分：1)
我像这样编写代码，因此更容易阅读：
object[prop] = object[prop].map(xss)
如果我想要在另一个Firebase调用之后运行Firebase调用，请将其放在onCreate() {
dataRef.addListenerForSingleValueEvent(new ValueEventListener() {
@Override
public void onDataChange(DataSnapshot dataSnapshot) {
doSomething(dataSnapshot);
...
}
...
}
}
doSomething(DataSnapshot dataSnapshot) {
...
}
内。
但是，如果该调用不必相继运行（例如“获取当前用户”和“从示例代码中获取所有用户”），我就这样做了：
doSomething希望得到这个帮助。