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问题 Based on a previous question, the following code compiles OK trait Logger { def log(msg: String): Unit } trait LoggerA extends Logger { def log(msg: String) = ??? } trait LoggerB extends Logger { override def log(msg: String) = ??? } class Logged1 extends LoggerA class Logged2 extends LoggerB class Logged3 extends LoggerA with LoggerB The override is not required in LoggerA because there is no concrete implementation of log in Logger . However if I remove the override from LoggerB it no

问题 Based on a previous question, the following code compiles OK trait Logger { def log(msg: String): Unit } trait LoggerA extends Logger { def log(msg: String) = ??? } trait LoggerB extends Logger { override def log(msg: String) = ??? } class Logged1 extends LoggerA class Logged2 extends LoggerB class Logged3 extends LoggerA with LoggerB The override is not required in LoggerA because there is no concrete implementation of log in Logger . However if I remove the override from LoggerB it no

问题 How can i make a callback to an Activity form a Java Class? Example: public class TestClass{ String text = "Test"; public TestClass(Context context){ startActivity(new Intent(context, SomeActivity.class)); } private void sendToSomeActivity(){ //Call some method of SomeActivity and pas text as string } } When sendToSomeActivity() is called, i want to make a callback to the already started SomeActivity and pass some text to the Activity. In SomeActivity i want to use the text. Note: The

问题 How can i make a callback to an Activity form a Java Class? Example: public class TestClass{ String text = "Test"; public TestClass(Context context){ startActivity(new Intent(context, SomeActivity.class)); } private void sendToSomeActivity(){ //Call some method of SomeActivity and pas text as string } } When sendToSomeActivity() is called, i want to make a callback to the already started SomeActivity and pass some text to the Activity. In SomeActivity i want to use the text. Note: The

问题 In the same vein as pg_dump without comments on objects?, is anyone aware of a command to quickly get rid of the comments (created with COMMENT ON ) on all objects at once ? For now, I resorted to bash generating a SQL script that would void one by one the comments on each table/view/column, but it is quite slow, especially with >4000 columns. Example: COMMENT ON COLUMN table1.column1 IS NULL; COMMENT ON COLUMN table1.column2 IS NULL; COMMENT ON COLUMN table1.column3 IS NULL; ... 回答1: I have

问题 I used same setting for enabling arbitrary load but now i faced some issues.I used alamofire for json parsing. info.plist settings: and error is : 回答1: your info plist hierarchy for transport should be like this 回答2: NSAppTransportSecurity provides the network layer security and only allow http secured urls. There are 2 ways to solve this: Case 1: In your code you are using an unsecure url with http:// replace it with https:// , then it will work. Case 2: If you don't have ssl enabled url

问题 I want to write a code that finds the length of longest continuous stretch of NA values in a column of a data-frame object. >> df [,1] [,2] [1,] 1 1 [2,] NA 1 [3,] 2 4 [4,] NA NA [6,] 1 NA [7,] NA 8 [8,] NA NA [9,] NA 6 # e.g. >> longestNAstrech(df[,1]) >> 3 >> longestNAstrech(df[,2]) >> 2 # What should be the length of longestNAstrech()? 回答1: Using base R we could create a function longestNAstrech <- function(x) { with(rle(is.na(x)), max(lengths[values])) } longestNAstrech(df[, 1]) #[1] 3

问题 I want to write a code that finds the length of longest continuous stretch of NA values in a column of a data-frame object. >> df [,1] [,2] [1,] 1 1 [2,] NA 1 [3,] 2 4 [4,] NA NA [6,] 1 NA [7,] NA 8 [8,] NA NA [9,] NA 6 # e.g. >> longestNAstrech(df[,1]) >> 3 >> longestNAstrech(df[,2]) >> 2 # What should be the length of longestNAstrech()? 回答1: Using base R we could create a function longestNAstrech <- function(x) { with(rle(is.na(x)), max(lengths[values])) } longestNAstrech(df[, 1]) #[1] 3

问题 I'm stuck with an issue. I have a Python script that I would like to run on my OSX but seems that I crossed on many issues. To run the script I should have both Python and Moviepy installed. To install Moviepy I used this command: sudo pip install moviepy The response was: sudo: pip: command not found So I tried to install pip, with the command: sudo easy_install pip And got this answer: Searching for pip Best match: pip 9.0.1 Processing pip-9.0.1-py2.7.egg pip 9.0.1 is already the active

问题 I used same setting for enabling arbitrary load but now i faced some issues.I used alamofire for json parsing. info.plist settings: and error is : 回答1: your info plist hierarchy for transport should be like this 回答2: NSAppTransportSecurity provides the network layer security and only allow http secured urls. There are 2 ways to solve this: Case 1: In your code you are using an unsecure url with http:// replace it with https:// , then it will work. Case 2: If you don't have ssl enabled url