constructing a waveform in vb.net. Can maybe someone give me a hint of how to make one? (a bit of code would be nice) I already know that to generate a waveform, you need a timer, if there anything else?
View 1 RepliesI'm looking for a free audio player control that has ability to display waveform of the audio being played.
View 1 RepliesI am having trouble constructing an SQL UPDATE string to do the following.
Table A (field, type) Table B
ID (key) Integer ID (key) Integer
ParentID Integer IssueID Integer
Number String ParentID Integer
[Code]...
I'm trying to draw a waveform graph(from mp3 & wav), I found this so far.
View 9 RepliesIs there a way to dynamically create properties at runtime in VB .NET using introspection?
e.g. Suppose I had a class
Public Class Foo
Public Property Bar() As String
get
...
end get
[code]....
Is there a way to create property Bar at runtime?
how to draw a waveform represenatation of a wave a wavefile and/or an MP3? Even better, can it be drawn in real-time while the file is playng?
View 8 RepliesI've been working in .NET for some time now, but occasionally I still get confused by a disparity between the framework and my prior experience in C++.In .NET, all objects are either value types or reference types. Reference types are allocated on the heap while value types are allocated on the stack (in the current CLR implementation, anyway). I get that. However, at least in VB.NET, you can still define a constructor on a value type.
Public Structure Coordinates
Public x As Integer
Public y As Integer
[code]....
How can I play a sound based on waveform data that my .Net program is generating from user input and mathematical functions? By "waveform data" I am mean SPL values in a fixed interval time-series (probably 44.1 kHz). I presume that this requires some kind of streaming buffer arrangement.Note, that this has to be live/real-time, so just creating a .wav file and then playing that will not be sufficient. VB.net is preferred, but C# is acceptable also.
View 4 RepliesI'm not entirely sure what to call what C# does, so I haven't had any luck searching for the VB.Net equivalent syntax (if it exists, which I suspect it probably doesn't).
In c#, you can do this:
public void DoSomething() {
new MyHelper().DoIt(); // works just fine
}
But as far as I can tell, in VB.Net, you must assign the helper object to a local variable or you just get a syntax error:
Public Sub DoSomething()
New MyHelper().DoIt() ' won't compile
End Sub
Just one of those curiosity things I run into from day to day working on mixed language projects - often there is a VB.Net equivalent which uses less than obvious syntax. Anyone?
I've used VB.net for several years now, but keep coming across little quirks that I don't know how to work around. Curiosity finally got the best of me, so I ask now: is there a way to create an object without assigning it?For example, say I have an Engine class, that I want to instantiate and have it immediately do whatever it needs to do. If there's nothing I need to do with Engine after creating it, I have, till now, done something like:dim myEngine as new Engine()Is there a way to avoid the "dim myEngine as" part? You certainly can in Java. I could just create an object with "new Engine()" in java and not assign it to anything.
Why do I need this? Because often I want to create a delegate object (hence I called it "engine") that performs some functionality, but otherwise I don't need to ever reference it. I used to have such objects have a "public sub perform", but have found that cumbersome -- I'd rather just create the object and not worry about remembering to call its perform method. And I find it aesthetically displeasing to create references to objects that I don't intend to use
Basically, my circuit board is connected to a solar cell and also a power supply(those laboratory DC power supply used in schools) and its connected to the computer via a RS232 Serial cable port. Thru the serial cable port, a voltage level is sensed and is displayed on the "Voltage Level in Volts(V)" -- See attach imageAs for now, i am also needed to display the voltage level into another type form intead of just Dial Voltmeter. Maybe to display the voltage level to a waveform like what we see on the oscilloscope ? I came across a suggestion from someone regarding the oscilloscope, but its in C# instead, and after converting, the codes does not work. Hmm.. ?
>> Therefore, i hope to get some guidance on how to display the voltage level into a waveform as what we see on the oscilloscope.
I need to be able to take an MP3 or WAV file and plot a graph of its waveform over time. Prefferably without playing it first. The representation doesn't have to be amazingly accurate as it's not for EQ purposes. I just need to pinpoint certain points in the MP3 / WAV when specific music / sounds etc occur (similar to the display in Windows Sound Recorder).
how I can go about that, or if it's even possible in VB 2005?
As mention in another thread ( if you have came across it --> Getting voltage from RS232 & allow dial voltmeter to point according to voltage level ), my circuit board is connected to solar cell and also a power supply(those laboratory DC power supply used in schools) and its connected to the computer via a RS232 Serial cable port. Thru the serial cable port, a voltage level is sensed and is displayed on the "Voltage Level in Volts(V)" -- See attach imageAs for now, i am also needed to display the voltage level into another type form intead of just Dial Voltmeter.Maybe to display the voltage level to a waveform like what we see on the oscilloscope ? I came across a suggestion from someone regarding the oscilloscope, but its in C# instead, and after converting, the codes does not work.
View 8 RepliesI have a specific problem that I have not yet found an answer to. Basically I need to pass a list of numbers into a function do some math and return them. I can pass one number at a time without a problem, however when I want to pass in an array I start to have issues. My VB.net code looks like this...
[Code]...
I have to set GridView.DataKeyNames(This is really a question about the syntax for a string array, in VB.Net.)I am discovering the PrimaryKey columns names from within a loop, ie:For Each fld As IEntityField In Me.llbDataSource.EntityCollection(0).PrimaryKeyFields'fld.Name ' this is where the column name is stored, so I have to get this into an array Next..[code]So, basically, how does one declare a string array (as required by GridView.DataKeyNames), and then populate the elements of the array from within a loop?
View 3 RepliesI am constructing a search function in a class to be used by several of our asp pages. The idea is simple, take a search term from the user and query the database for the item. Currently I am doing this the wrong way, which is vulnerable to SQL injection attacks (and ELMAH is in there to save the day if something goes wrong):
[Code]...
The problem is since I am using a like statement, I need to be able to have % on either side of the search word, and I can't seem to do that with '%:searchterm%', it just gives an error of ORA-01036: illegal variable name/number.Can I parameterize but still have my flexible like statement be a part of it?
Given this illustration and basic code, how do I dequeue and draw the data that has been inserted into the User Control's Preperty queue? The graph/chart will need to show anywhere from 1 to 120 seconds of data, with each second representing electrical waveform data that arrives each second with a variable amount of sample data..The timer interval will have to vary with the amount of incoming data so that it shows a continuously moving waveform from right to left and the rate of drawing keeps up with the amount of data arriving. (so the queue doesn't get backed up)
View 7 RepliesI'm creating an emulator for a device to simulate wave forms. My challenge is that when I try to convert the output of the following code, I can't convert the Math.Sin's double output into byte values that lend themselves to the byte array format required by an existing graphing control as listed at bottom below. I''m not sure how to handle this when the sin function creates negative values but the byte values will need to be positive and basically 'shifted up' so that anything over 127 is negative. (0 - 255) unsigned. BitConverter.GetBytes has been suggested but THIS is the result of that attempt.
[Code]....
Using MS Visual Studio 2010 Express, when trying to debug, the build finishes and the following error below appears. It doesn't seem to effect the running of the program.
The error is:
An exception was encountered while constructing the content of this frame. This information is also logged by running the application with the /log parameter on the command line, which stores results in "C:Documents and SettingsCorkyApplication
DataMicrosoftVBExpress10.0ActivityLog.xml".
Exception details:
System.Runtime.InteropServices.COMException (0x80040154): Class not registered (Exception from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))[code].....
I can't find the "ActivityLog.xml" file the message references.