大约有 48,000 项符合查询结果（耗时：0.0314秒） [XML]
How to use OpenFileDialog to select a folder?
... result = fbd.ShowDialog();
if (result == DialogResult.OK && !string.IsNullOrWhiteSpace(fbd.SelectedPath))
{
string[] files = Directory.GetFiles(fbd.SelectedPath);
System.Windows.Forms.MessageBox.Show("Files found: " + files.Length.ToString(), "Message");
}
}
...
What is the performance cost of having a virtual method in a C++ class?
...roblem specific to..." it's a tad worse for virtual dispatch as there's an extra page (or two if it happens to fall across a page boundary) that has to be in cache - for the class's Virtual Dispatch Table.
– Tony Delroy
May 13 '14 at 1:12
...
print call stack in C or C++
...tdio.h>
#include <execinfo.h>
void print_trace(void) {
char **strings;
size_t i, size;
enum Constexpr { MAX_SIZE = 1024 };
void *array[MAX_SIZE];
size = backtrace(array, MAX_SIZE);
strings = backtrace_symbols(array, size);
for (i = 0; i < size; i++)
pr...
What's the best way to share data between activities?
...in the intent's extras or saving it somewhere else. If data is primitives, Strings or user-defined objects: send it as part of the intent extras (user-defined objects must implement Parcelable). If passing complex objects save an instance in a singleton somewhere else and access them from the launch...
How to define a preprocessor symbol in Xcode
...
As an addendum, if you are using this technique to define strings in your target, this is how I had to define and use them:
In Build Settings -> Preprocessor Macros, and yes backslashes are critical in the definition:
APPURL_NSString=\@\"www.foobar.org\"
And in the source cod...
string c_str() vs. data()
...
The documentation is correct. Use c_str() if you want a null terminated string.
If the implementers happend to implement data() in terms of c_str() you don't have to worry, still use data() if you don't need the string to be null terminated, in some implementation it may turn out to perform bett...
Is gcc's __attribute__((packed)) / #pragma pack unsafe?
...7
p1 = ffbff31c
Bus error
In both cases, the program is compiled with no extra options, just gcc packed.c -o packed.
(A program that uses a single struct rather than array doesn't reliably exhibit the problem, since the compiler can allocate the struct on an odd address so the x member is properl...
event Action vs event EventHandler
... you don't get named parameters, so if you're passing 3 bool's an int, two string's, and a DateTime, you have no idea what the meaning of those values are. As a side note, you can still have a "Fire this event safely method while still using Action<T1, T2, T2... >".
Secondly, consistency impl...
REST API 404: Bad URI, or Missing Resource?
... Don't return 200 with an empty body.
This is akin to undefined vs empty string (e.g. "") in programming. While very similar, there is definitely a difference.
404 means that nothing exists at that URI (like an undefined variable in programming). Returning 200 with an empty body means that some...
How to change value of object which is inside an array using JavaScript or jQuery?
...alue: 'lol1',
desc: 'lol2'
}
};
projects.jqueryUi.desc = 'new string';
(In according to Frédéric's comment you shouldn't use hyphen in the object key, or you should use "jquery-ui" and projects["jquery-ui"] notation.)
...