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问题 i have been all over the web, stackoverflow included and just can't seem to get a clear complete way to I want to create a ListView that 1) has alternating colors (I am able to do that with code below) 2) retains the default orange selection behavior of android to accomplish #1 I have an custom adapter that extends ArrayAdapter and then I override getView like so public View getView(int position, View convertView, ViewGroup parent) { .... // tableLayoutId is id pointing to each view/row in my

问题 I'm an intermediate user in jQuery. I know to find the rowIndex of a table using jQUery, but my scenario is a different one. My table(GridView) consists of 20 columns and each column with different controls like textbox, dropdownlist, image, label. All are server side controls in each row. I bind the gridview with the records from the database. Now when I click on any control or onchange of any textbox, I need to get the rowIndex of that changed column's row. Here is the code I've user: $("

问题 I have searched extensively but not found an answer to this question on Stack Overflow. Lets say I have a data frame a. I define: a <- NULL a <- as.data.frame(a) If I wanted to add a column to this data frame as so: a$col1 <- c(1,2,3) I get the following error: Error in `$<-.data.frame`(`*tmp*`, "a", value = c(1, 2, 3)) : replacement has 3 rows, data has 0 Why is the row dimension fixed but the column is not? How do I change the number of rows in a data frame? If I do this (inputting the data

问题 Suppose I have a matrix in the CSR format, what is the most efficient way to set a row (or rows) to zeros? The following code runs quite slowly: A = A.tolil() A[indices, :] = 0 A = A.tocsr() I had to convert to scipy.sparse.lil_matrix because the CSR format seems to support neither fancy indexing nor setting values to slices. 回答1: I guess scipy just does not implement it, but the CSR format would support this quite well, please read the wikipedia article on "Sparse matrix" about what indptr ,

问题 I know that there are TTLs on columns in Cassandra. But is it also possible to set a TTL on a row? Setting a TTL on each column doesn't solve my problem as can be seen in the following usecase: At some point a process wants to delete a complete row with a TTL (let's say row "A" with TTL 1 week). It could do this by replacing all existing columns with the same content but with a TTL of 1 week. But there may be another process running concurrently on that row "A" which inserts new columns or

问题 I set the min height of a datagrid that way: <DataGrid MinRowHeight="40"> After feeding the datagrid with datas, the text in each cell is top and left aligned. I could not find an easy way to center that text. Any suggestions for doing that? 回答1: Final solution: <Style x:Key="DataGridContentCellCentering" TargetType="{x:Type DataGridCell}"> <Setter Property="Template"> <Setter.Value> <ControlTemplate TargetType="{x:Type DataGridCell}"> <Grid Background="{TemplateBinding Background}">

问题 I have a dataframe such as this one: d <- data.frame(cbind(x=1, y=1:10, z=c("apple","pear","banana","A","B","C","D","E","F","G")), stringsAsFactors = FALSE) I'd like to delete some rows from this dataframe, depending on the content of column z: new_d <- d[-grep("D",d$z),] This works fine; row 7 is now deleted: new_d x y z 1 1 1 apple 2 1 2 pear 3 1 3 banana 4 1 4 A 5 1 5 B 6 1 6 C 8 1 8 E 9 1 9 F 10 1 10 G However, when I use grep to search for content that is not present in column z, it

问题 How do I get the row count of a query in Android using SQLite? It seems my following method does not work. public int getFragmentCountByMixId(int mixId) { int count = 0; SQLiteDatabase db = dbOpenHelper.getWritableDatabase(); Cursor cursor = db.rawQuery( "select count(*) from downloadedFragement where mixId=?", new String[]{String.valueOf(mixId)}); while(cursor.moveToFirst()){ count = cursor.getInt(0); } return count; } 回答1: Cursor.getCount() 回答2: cursor.moveToNext(); cursor.getCount(); If

问题 This question already has answers here : Closed 7 years ago . Possible Duplicate: R: losing column names when adding rows to an empty data frame I created an empty dataframe with column names only as follows > compData <- data.frame(A= numeric(0), B= numeric(0)) > compData [1] A B <0 rows> (or 0-length row.names) > compData <- rbind(compData,c(5,443)) > compData X5 X443 1 5 443 in the above after adding one row the column names are changed. How can I add new row data to data-frame? 回答1:

问题 After watching many threads about getting selected rows numbers, I am really confused. How do you get ROW numbers in QTableView using QStandardItemModel I used below selection model and behavior as setSelectionBehavior(QAbstractItemView::SelectRows); setSelectionMode(QAbstractItemView::SingleSelection); and if you have your own way of selecting can you explain how it works. Thanks for the help! 回答1: The method selectionModel() return a QItemSelectionModel . You can use QItemSelectionModel