Vala

问题 I am using GStreamer 1.0 in my program to play video from file. And I want to output it to Gdk.Pixbuf to add it to Image to display it. But I can't figure out how to use it properly. Here is what I tried to do, but it won't compile: this.pipeline = new Pipeline ("mypipeline"); this.src = ElementFactory.make ("filesrc", "video"); src.set("location", downloadFileName); this.sink = ElementFactory.make ("gdkpixbufsink", "sink"); this.pipeline.add_many (this.src, this.sink); this.src.link (this

问题 This question is a spin off a previous question here in which a database was created. However, when it comes to add information to that dataset I can go manually adding information or going via a programmatically way. The latter is my choice for a didactic reason. The equivalent of what I am trying to do in python is: for x in cursor.execute(sql): lastid = x[0] # Insert data into the instructions table sql = 'INSERT INTO Instructions (recipeID,instructions) VALUES( %s,"Brown hamburger. Stir

问题 I need to rotate a Pixbuf. The vala code contains using Gst, GLib, Posix, Sqlite, Gdk; public class RotateSaveImage { public void RotateSaveImage(string input, string output) { var img = new Pixbuf.from_file(input); var rotate_image = img.rotate_simple(PixbufRotation.CLOCKWISE); rotate_image.save(output, "jpeg"); } } The makefile contains test_VALAFLAGS = --vapidir=@VAPIDIR@ --pkg gstreamer-0.10 --pkg glib-2.0 --pkg gio-2.0 --pkg posix --thread --pkg gstreamer-app-0.10 --pkg sqlite3 --pkg gtk

问题 I am using the glib vala function glib.process.spawn_async_with_pipes()(http://references.valadoc.org/#!api=glib-2.0/GLib.Process.spawn_async_with_pipes), which outputs some ints corresponding to stdin, stdout, and stderr. How would I use these pipes in Vala? 回答1: Modified example which also writes stuff to stdin: private static bool process_line (IOChannel channel, IOCondition condition, string stream_name) { if (condition == IOCondition.HUP) { stdout.printf ("%s: The fd has been closed.\n",

问题 Is there any way that Vala supports Self Invoking? Either with a class, or with a method? Javascript supports self invoking like below. Which is what im looking for. (function(){ // some code… })(); I'm attempting to load a class into a hashmap for dynamically loading. 回答1: using Gee; [CCode (has_target = false)] delegate void MyDelegate(); int main() { var map = new HashMap<string, MyDelegate>(); map["one"] = () => { stdout.printf("1\n"); }; map["two"] = () => { stdout.printf("2\n"); };

问题 I write this code, repeatc for repeat char to char array. it works. repeats for repeat string N times to an string array. but repeat string to string array core dumped. A, A, A, AB, AB, AB, *** Error in `./untitled': free(): invalid pointer: 0x0000000000400f3d *** .... .... Aborted (core dumped) why? my code: // --cc='gcc' [indent=4] init var carray = repeatc ('A', 3) for i in carray do stdout.printf ("%c, ", i) // A, A, A stdout.putc ('\n') var sarray = repeats ("AB", 3) for i in sarray do

问题 I am trying to log on to my tt-rss server using libsoup. Since version 1.5.3 it only supports HTTP POST to receive data. Basically I only need to do something like this with libsoup: curl -d '{"op":"login","user":"you","password":"xxx"}' http://example.dom/tt-rss/api/ But all the code examples written in vala using POST are outdated and don't compile anymore. For example the last one on this page, Transmission RPC Interface: https://wiki.gnome.org/Projects/Vala/JsonSample Here is my code: var

问题 genie! how to Sort an array (or list) of strings in order of descending length, and in ascending lexicographic order for strings of equal length. my data is datas : array of string = { "cold", "z", "bpples", "pallalala", "apples", "xccv" } 回答1: Genie and Vala's built-in array type is not very friendly since it really a C array underneath. You'd have to use C's qsort function to do it. I would recommend you use a Gee.List instead, which has a nice sort method that takes a comparator: var list

问题 I'm writing program using Vala language. When I try to build a .deb package on Launchpad, I get this error CMake can't find valac package gtk+-3.0 . It uses valac version 0.30 . Though it does find it, when I do this on my computer (use cmake to build). This is first time I try to build .deb package, so I'm a bit confused with what to do... Can anyone tell me how to fix this? Thanks in advance. 回答1: The error is quite clear, CMake can't find the pkg-config package named 'gtk+-3.0'. You have

问题 I am new to Vala and playing around a bit. Currently I am looking for a way to determine the type parameter of a generic list at runtime. The code below uses 'reflection' to print the properties of the Locations class. However, I am not able to determine at runtime that this list contains instances of string. Is there a way to do this? Or is this not supported in Vala? using Gee; class Locations : Object { public string numFound { get; set; } public ArrayList<string> docs { get; set; } } void