Sorting NSTableView

问题:

I have two coloumn in NSTableView as Name and Salary with 5-10 values. I want to sort these coloumn after click on header of both the column. There is lots of data present in Internet but I am not able to use these. Please help me to do this in cocoa.

Thanks in advance and appreciate any help.

回答1:

Each table column has a method setSortDescriptorPrototype Sort descriptors are ways of telling the array how to sort itself (ascending, descending, ignoring case etc.) Iterate over each of the columns you want as sortable and call this method on each of those columns, and pass the required sort descriptor (In my case I'll be using the column identifier)

for (NSTableColumn *tableColumn in tableView.tableColumns ) {

    NSSortDescriptor *sortDescriptor = [NSSortDescriptor sortDescriptorWithKey:tableColumn.identifier ascending:YES selector:@selector(compare:)];
    [tableColumn setSortDescriptorPrototype:sortDescriptor];
}

After writing this piece of initialization code, NSTableViewDelegate has a method - (void)tableView:(NSTableView *)aTableView sortDescriptorsDidChange:(NSArray *)oldDescriptors that notifies you whenever a sort descriptor is changed, implement this method in the delegate and send a message to the data array to sort itself

- (void)tableView:(NSTableView *)aTableView sortDescriptorsDidChange:(NSArray *)oldDescriptors
{
    self.data = [self.data sortedArrayUsingDescriptors:sortDescriptors];
    [aTableView reloadData];
}

This method will get fired each time a column header is clicked, and NSTableColumn shows a nice little triangle showing the sorting order.

回答2:

I stumbled upon this question while looking for the easiest way of implementing something similar. Although the original question is old, I hope someone finds my answer useful! Please note that I am using Xcode 5.1.1

Ok so to do this you need to:

1. select the actual column you want to sort in your table.
2. In your Attributes Inspector you need to fill in two fields: Sort Key, and Selector.
3. In the Sort Key field, you need to enter the value of your Identifier. The value of your Identifier is located in your Identity Inspector.
4. In the Selector field you need to enter a suitable selector method based on the object type in the column. The default method is; compare:

Based on the Table View Programming Guide for Mac. The compare: method works with NSString, NSDate, and NSNumber objects. If your table column contains only strings, you may want to consider using the caseInsensitiveCompare: method if case sensitivity is unimportant. However, consider replacing these method signatures with the localizedCompare: or localizedCaseInsensitiveCompare: methods to take into the account the user’s language requirements.

Finally, you need to declare the tableView:sortDescriptorsDidChange: method in your Table View Controller in the format shown below:

-(void)tableView:(NSTableView *)mtableView sortDescriptorsDidChange:(NSArray *)oldDescriptors
{
    [listArray sortUsingDescriptors: [mtableView sortDescriptors]];
    [tableView reloadData];
}