I'm writing a program that contains a simple MP3/WAV media player area.
I've followed the code contained within the NAudio sample programs and this is the class I created to encapsulate a playable audio file:
public sealed class PlaybackContext : IDisposable {
private String _fileName;
private DirectSoundOut _dsoundOut;
private WaveStream _waveStream;
public PlaybackContext(String fileName) {
_fileName = fileName;
_dsoundOut = new DirectSoundOut( DirectSoundOut.DSDEVID_DefaultPlayback );
String ext = Path.GetExtension( fileName );
if( ext.Equals(".mp3", StringComparison.OrdinalIgnoreCase) ) {
_waveStream = new Mp3FileReader( fileName );
} else if( ext.Equals(".wav", StringComparison.OrdinalIgnoreCase) ) {
_waveStream = new WaveFileReader( fileName );
switch( _waveStream.WaveFormat.Encoding ) {
case WaveFormatEncoding.Pcm:
case WaveFormatEncoding.IeeeFloat:
break;
default:
_waveStream = new BlockAlignReductionStream( WaveFormatConversionStream.CreatePcmStream( _waveStream ) );
break;
}
}
_dsoundOut.Init( _waveStream );
}
public void Play() {
_dsoundOut.Play();
}
// hidden are the Pause/Stop/Dispose methods
It works fine for MP3 files, but when I try to play any Wave files I get this exception:
Object contains non-primitive or non-blittable data.
System.ArgumentException
at System.Runtime.InteropServices.GCHandle.InternalAlloc(Object value, GCHandleType type)
at System.Runtime.InteropServices.GCHandle.Alloc(Object value, GCHandleType type)
at NAudio.Wave.DirectSoundOut.InitializeDirectSound()
at NAudio.Wave.DirectSoundOut.PlaybackThreadFunc()
at System.Threading.ThreadHelper.ThreadStart_Context(Object state)
at System.Threading.ExecutionContext.Run(ExecutionContext executionContext, ContextCallback callback, Object state)
at System.Threading.ThreadHelper.ThreadStart()
I can't find anything with Google, and my code is compiled for x86 (so this isn't a 64-bit issue). Otherwise I'm stuck.
Any ideas?
Related
Normally, the .Dump() extension method in LINQPad shows XNode and its derived class instances as a rendered XML fragment. Sometimes while developing code I would prefer to see actual properties of the object, in the same table form that is dumped for other types, like a table that would show the Name, Value, FirstAttribute and whatsnot properties of the node and their .ToString() values, or interactively expandable collections of subobjects. In short, as if XNode were not handled specially at all.
I am working around this by dumping individual properties, but this is tedious.
This answer suggests writing a custom extension code to achieve a similar effect for another type, namely IEnumerable, but it seems a narrower and rarer case than that which I am dealing with.
Is there an out-of-the box way to do what I want?
LINQPad supports customizing Dump for types. Using some extension methods, you can convert the types to ExpandoObjects and then they will be output with properties.
In My Extensions, after the MyExtensions class, add a top level method:
static object ToDump(object obj) {
if (obj is XObject x)
return x.ToExpando();
else
return obj;
}
In the MyExtensions class, add the following extension methods. I already had the object->Dictionary methods for converting to anonymous objects, so I used those, but you could combine them to create a single ToExpando on object:
public static ExpandoObject ToExpando(this object obj) => obj.ToDictionary().ToExpando();
public static IDictionary<string, object> ToDictionary(this object obj) {
if (obj is IDictionary<string, object> id)
return id;
else {
var dictAnsObj = new Dictionary<string, object>();
foreach (var prop in obj.GetType().GetPropertiesOrFields()) {
try {
dictAnsObj.Add(prop.Name, prop.GetValue(obj));
}
catch (Exception ex) {
dictAnsObj.Add(prop.Name, ex);
}
}
return dictAnsObj;
}
}
public static ExpandoObject ToExpando(this IDictionary<string, object> objDict) {
var e = new ExpandoObject();
var di = (IDictionary<string, object>)e;
foreach (var kvp in objDict)
di.Add(kvp);
return e;
}
You will also need this Type extension:
// ***
// *** Type Extensions
// ***
public static List<MemberInfo> GetPropertiesOrFields(this Type t, BindingFlags bf = BindingFlags.Public | BindingFlags.Instance) =>
t.GetMembers(bf).Where(mi => mi.MemberType == MemberTypes.Field | mi.MemberType == MemberTypes.Property).ToList();
If you are okay with just displaying the top level object in class format, you could just use this extension method when you need to:
public static T DumpAs<T, NewT>(this T obj, Func<T, NewT> castFn, string description = null) {
if (description != null)
castFn(obj).Dump(description);
else
castFn(obj).Dump();
return obj;
}
For example,
XElement xn;
xn.DumpAs(x => x.ToExpando());
Otherwise, you will have to comment out the ToDump method or do something tricky with fluent methods to turn it on and off.
This answer depends on the previous answer, but extends it to handle dumping XObjects as classes when desired with an alternative extension method and ToDump method. It uses the same extensions as my previous answer otherwise.
In the MyExtensions class, add a new type of dump and a bool to track status:
public static bool bDumpAsClass = false;
public static object DumpAsClass(this object input, string descr = null) {
bDumpAsClass = true;
if (descr != null)
input.Dump(descr);
else
input.Dump();
bDumpAsClass = false;
return input;
}
Outside the MyExtensions class, add a ToDump method that uses the bool:
static object ToDump(object obj) {
if (MyExtensions.bDumpAsClass) {
if (obj is XObject x)
return x.ToExpando();
}
return obj;
}
Then you can just use DumpAsClass instead of Dump when you want to dump an XObject or descendant as a class, expanding any members as well.
Obviously you could expand the types handled when bDumpAsClass is true.
I have a class named VerseRangeReference that has the properties Chapter, FirstVerse and LastVerse.
I have decorated it with a TypeConverterAttribute [TypeConverter(typeof(VerseRangeReferenceConverter))]
I have an action on a controller like this
public Task<ViewResult> Verses(VerseRangeReference[] verses)
But the value of verses is always a single element with the value null. Here is my type converter
public class VerseRangeReferenceConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
return sourceType == typeof(string);
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
if (value == null)
throw new ArgumentNullException(nameof(value));
if (value.GetType() == typeof(string))
{
string source = (string)value;
return VerseRangeReference.ParseMultiple(source);
}
return null;
}
}
The result of VerseRangeReference.ParseMultiple(source) is a valid array of instances of VerseRange.
I had to implement a custom model binder. If someone can think of a way to do this with a TypeConverter then I will accept that answer instead because model binders are more complicated.
public class VerseRangeReferenceArrayModelBinder : IModelBinder
{
public Task BindModelAsync(ModelBindingContext bindingContext)
{
string modelName = bindingContext.ModelName;
ValueProviderResult valueProviderResult = bindingContext.ValueProvider.GetValue(modelName);
if (valueProviderResult != ValueProviderResult.None)
{
VerseRangeReference[] verseRangeReferences = VerseRangeReference.ParseMultiple(valueProviderResult.FirstValue);
bindingContext.Result = ModelBindingResult.Success(verseRangeReferences);
}
return Task.CompletedTask;
}
}
public class VerseRangerReferenceArrayModelBinderProvider : IModelBinderProvider
{
public IModelBinder GetBinder(ModelBinderProviderContext context)
{
if (context.Metadata.ModelType == typeof(VerseRangeReference[]))
return new BinderTypeModelBinder(typeof(VerseRangeReferenceArrayModelBinder));
return null;
}
}
This must be registered.
services.AddMvc(options =>
{
options.ModelBinderProviders.Insert(0, new VerseRangerReferenceArrayModelBinderProvider());
})
.SetCompatibilityVersion(CompatibilityVersion.Version_2_1);
You can use a type converter to bind a comma separated string to a sequence of values. However, the type converter should convert from the string to the sequence directly. This means that the type converter should be configured for something like IEnumerable<T> or T[]. To simplify matters I will continue my explanation for IEnumerable<int> but if you want to use arrays instead you should just make sure that the type converter converts to an array instead of something that implements IEnumerable<T>.
You can configure a type converter for IEnumerable<int> using TypeDescriptor.AddAttributes:
TypeDescriptor.AddAttributes(
typeof(IEnumerable<int>),
new TypeConverterAttribute(typeof(EnumerableIntTypeConverter)));
This configures EnumerableIntTypeConverter as a type converter that can convert IEnumerable<int>.
This call has to be made when the process starts and in the case of ASP.NET Core this can conveniently be done in the Startup.Configure method.
Here is the EnumerableIntTypeConverter that converts the comma separated string of numbers to a list of ints:
internal class EnumerableIntTypeConverter : TypeConverter
{
private const char Separator = ',';
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
=> sourceType == typeof(string);
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
if (!(value is string #string))
throw new NotSupportedException($"{GetType().Name} cannot convert from {(value != null ? value.GetType().FullName : "(null)")}.");
if (#string.Length == 0)
return Enumerable.Empty<int>();
var numbers = new List<int>();
var start = 0;
var end = GetEnd(#string, start);
while (true)
{
if (!int.TryParse(
#string.AsSpan(start, end - start),
NumberStyles.AllowLeadingSign,
culture,
out var number))
throw new FormatException($"{GetType().Name} cannot parse string with invalid format.");
numbers.Add(number);
if (end == #string.Length)
break;
start = end + 1;
end = GetEnd(#string, start);
}
return numbers;
}
private static int GetEnd(string #string, int start)
{
var end = #string.IndexOf(Separator, start);
return end >= 0 ? end : #string.Length;
}
}
The parsing uses System.Memory to avoid allocating a new string for each number in the list. If your framework doesn't have the int.TryParse overload that accepts a Span<char> you can use string.Substring instead.
Considering this IronPython script
def SensorEvent(d):
print d
print d.Message
... how do I access properties of d?
First line of the SensorEvent method successfully prints
{ Message = blah blubb }
however second line throws an exception:
'<>f_anonymousType[str]' object has no attribute 'Message'
Explanation
d is an instance of an anonymous type provided by an invoke from a C# method. I'm invoking it like this:
public static async void ExecutePyFunc(string name, dynamic data)
{
try
{
var f = strategyScope.GetVariable<Action<object>>(name);
if (f != null)
{
await Task.Run(() => f((object)data));
}
}
catch (Exception x)
{
StaticLog("[Callback Exception] Fehler beim Ausführen einer Python Funktion: {0}", x.Message);
}
}
d is a dictionary. Access it like so:
d['Message']
My solution using DynamicObject: I've introduced a class that converts an anonymous type into a known type by copying its properties via reflection (I don't need anything but the properties but it could probably be enhanced for use with fields, methods, functions as well).
Here's what I've come up with:
public class IronPythonKnownType : DynamicObject
{
public IronPythonKnownType(dynamic obj)
{
var properties = obj.GetType().GetProperties();
foreach (PropertyInfo prop in properties)
{
var val = prop.GetValue(obj);
this.Set(prop.Name, val);
}
}
private Dictionary<string, object> _dict = new Dictionary<string, object>();
public override bool TryGetMember(GetMemberBinder binder, out object result)
{
if (_dict.ContainsKey(binder.Name))
{
result = _dict[binder.Name];
return true;
}
return base.TryGetMember(binder, out result);
}
private void Set(string name, object value)
{
_dict[name] = value;
}
public override bool TrySetMember(SetMemberBinder binder, object value)
{
_dict[binder.Name] = value;
return true;
}
}
which effectively converts the anonymous object into something IronPython can handle.
Now I can do that:
def Blubb(a):
print a.Message
without getting the mentioned exception.
Just came across the latest build of Mono.CSharp and love the promise it offers.
Was able to get the following all worked out:
namespace XAct.Spikes.Duo
{
class Program
{
static void Main(string[] args)
{
CompilerSettings compilerSettings = new CompilerSettings();
compilerSettings.LoadDefaultReferences = true;
Report report = new Report(new Mono.CSharp.ConsoleReportPrinter());
Mono.CSharp.Evaluator e;
e= new Evaluator(compilerSettings, report);
//IMPORTANT:This has to be put before you include references to any assemblies
//our you;ll get a stream of errors:
e.Run("using System;");
//IMPORTANT:You have to reference the assemblies your code references...
//...including this one:
e.Run("using XAct.Spikes.Duo;");
//Go crazy -- although that takes time:
//foreach (Assembly assembly in AppDomain.CurrentDomain.GetAssemblies())
//{
// e.ReferenceAssembly(assembly);
//}
//More appropriate in most cases:
e.ReferenceAssembly((typeof(A).Assembly));
//Exception due to no semicolon
//e.Run("var a = 1+3");
//Doesn't set anything:
//e.Run("a = 1+3;");
//Works:
//e.ReferenceAssembly(typeof(A).Assembly);
e.Run("var a = 1+3;");
e.Run("A x = new A{Name=\"Joe\"};");
var a = e.Evaluate("a;");
var x = e.Evaluate("x;");
//Not extremely useful:
string check = e.GetVars();
//Note that you have to type it:
Console.WriteLine(((A) x).Name);
e = new Evaluator(compilerSettings, report);
var b = e.Evaluate("a;");
}
}
public class A
{
public string Name { get; set; }
}
}
And that was fun...can create a variable in the script's scope, and export the value.
There's just one last thing to figure out... how can I get a value in (eg, a domain entity that I want to apply a Rule script on), without using a static (am thinking of using this in a web app)?
I've seen the use compiled delegates -- but that was for the previous version of Mono.CSharp, and it doesn't seem to work any longer.
Anybody have a suggestion on how to do this with the current version?
Thanks very much.
References:
* Injecting a variable into the Mono.CSharp.Evaluator (runtime compiling a LINQ query from string)
* http://naveensrinivasan.com/tag/mono/
I know it's almost 9 years later, but I think I found a viable solution to inject local variables. It is using a static variable but can still be used by multiple evaluators without collision.
You can use a static Dictionary<string, object> which holds the reference to be injected. Let's say we are doing all this from within our class CsharpConsole:
public class CsharpConsole {
public static Dictionary<string, object> InjectionRepository {get; set; } = new Dictionary<string, object>();
}
The idea is to temporarily place the value in there with a GUID as key so there won't be any conflict between multiple evaluator instances. To inject do this:
public void InjectLocal(string name, object value, string type=null) {
var id = Guid.NewGuid().ToString();
InjectionRepository[id] = value;
type = type ?? value.GetType().FullName;
// note for generic or nested types value.GetType().FullName won't return a compilable type string, so you have to set the type parameter manually
var success = _evaluator.Run($"var {name} = ({type})MyNamespace.CsharpConsole.InjectionRepository[\"{id}\"];");
// clean it up to avoid memory leak
InjectionRepository.Remove(id);
}
Also for accessing local variables there is a workaround using Reflection so you can have a nice [] accessor with get and set:
public object this[string variable]
{
get
{
FieldInfo fieldInfo = typeof(Evaluator).GetField("fields", BindingFlags.NonPublic | BindingFlags.Instance);
if (fieldInfo != null)
{
var fields = fieldInfo.GetValue(_evaluator) as Dictionary<string, Tuple<FieldSpec, FieldInfo>>;
if (fields != null)
{
if (fields.TryGetValue(variable, out var tuple) && tuple != null)
{
var value = tuple.Item2.GetValue(_evaluator);
return value;
}
}
}
return null;
}
set
{
InjectLocal(variable, value);
}
}
Using this trick, you can even inject delegates and functions that your evaluated code can call from within the script. For instance, I inject a print function which my code can call to ouput something to the gui console window:
public delegate void PrintFunc(params object[] o);
public void puts(params object[] o)
{
// call the OnPrint event to redirect the output to gui console
if (OnPrint!=null)
OnPrint(string.Join("", o.Select(x => (x ?? "null").ToString() + "\n").ToArray()));
}
This puts function can now be easily injected like this:
InjectLocal("puts", (PrintFunc)puts, "CsInterpreter2.PrintFunc");
And just be called from within your scripts:
puts(new object[] { "hello", "world!" });
Note, there is also a native function print but it directly writes to STDOUT and redirecting individual output from multiple console windows is not possible.
I'm using a HeaderColumnNameMappingStrategy to map a csv file with a header into a JavaBean. String values parse fine but any "true" or "false" value in csv doesn't map to JavaBean and I get the following exception from the PropertyDescriptor:
java.lang.IllegalArgumentException: argument type mismatch
The code where it occurs is in CsvToBean, line 64:
protected T processLine(MappingStrategy<T> mapper, String[] line) throws
IllegalAccessException, InvocationTargetException, InstantiationException, IntrospectionException {
T bean = mapper.createBean();
for(int col = 0; col < line.length; col++) {
String value = line[col];
PropertyDescriptor prop = mapper.findDescriptor(col);
if (null != prop) {
Object obj = convertValue(value, prop);
// this is where exception is thrown for a "true" value in csv
prop.getWriteMethod().invoke(bean, new Object[] {obj});
}
}
return bean;
}
protected PropertyEditor getPropertyEditor(PropertyDescriptor desc) throws
InstantiationException, IllegalAccessException {
Class<?> cls = desc.getPropertyEditorClass();
if (null != cls) return (PropertyEditor) cls.newInstance();
return getPropertyEditorValue(desc.getPropertyType());
}
I can confirm (via debugger) that the setter method id correctly retrieved at this point.
The problem occurs in desc.getPropertyEditorClass() since it returns null. I assumed primitive types and its wrappers are supported. Are they not?
I've run into this same issue. The cleanest way is probably to override getPropertyEditor like pritam did above and return a custom PropertyEditor for your particular object. The quick and dirty way would be to override convertValue in anonymous class form, like this:
CsvToBean<MyClass> csvToBean = new CsvToBean<MyClass>(){
#Override
protected Object convertValue(String value, PropertyDescriptor prop) throws InstantiationException,IllegalAccessException {
if (prop.getName().equals("myWhatever")) {
// return an custom object based on the incoming value
return new MyWhatever((String)value);
}
return super.convertValue(value, prop);
}
};
This is working fine for me with OpenCSV 2.3. Good luck!
I resolved this by extending CsvToBean and adding my own PropertyEditors. Turns out opencsv just supports primitive types and no wrappers.
Pritam's answer is great and this is a sample for dealing with datetime format.
PropertyEditorManager.registerEditor(java.util.Date.class, DateEditor.class);
You should write your own editor class like this:
public class DateEditor extends PropertyEditorSupport{
public static final SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
#Override
public void setAsText(String text){
setValue(sdf.parse(text));}
}