public async Task <IValueProvider> BindAsync(object value, ValueBindingContext context)
{
string path = (string)value;
IFileStreamProvider strategy = await GetStreamHelper(path);
var outTuple = await strategy.OpenWriteStreamAsync();
Stream outStream = outTuple.Item1;
Func <object, Task> completedFunc = outTuple.Item2;
// Bind to 'out string'
var valueProvider = new GenericOutFileValueProvider(outStream, completedFunc);
return(valueProvider);
}
public async Task <IValueProvider> BindAsync(object value, ValueBindingContext context)
{
string path = (string)value;
IFileStreamProvider strategy = await GetStreamHelper(path);
var targetType = _parameter.ParameterType;
object userObj = null;
Func <object, Task> onComplete;
ConstantObj valueProvider = null;
if (_source.Access == FileAccess.Write)
{
var tuple = await strategy.OpenWriteStreamAsync();
var writeStream = tuple.Item1;
var saveStreamFunc = tuple.Item2;
if (targetType == typeof(Stream) || (_parameter.IsOut && targetType == typeof(Stream).MakeByRefType()))
{
userObj = writeStream;
onComplete = saveStreamFunc;
}
else if (targetType == typeof(TextWriter) || (_parameter.IsOut && targetType == typeof(TextWriter).MakeByRefType()))
{
var tw = new StreamWriter(writeStream);
userObj = tw;
onComplete = async obj =>
{
tw.Flush();
await saveStreamFunc(obj);
};
}
else if (targetType == typeof(StreamWriter) || (_parameter.IsOut && targetType == typeof(StreamWriter).MakeByRefType()))
{
var tw = new StreamWriter(writeStream);
userObj = tw;
onComplete = async obj =>
{
tw.Flush();
await saveStreamFunc(obj);
};
}
else if (targetType == typeof(byte[]) || (_parameter.IsOut && targetType == typeof(byte[]).MakeByRefType()))
{
userObj = writeStream;
onComplete = saveStreamFunc;
}
else
{
throw new InvalidOperationException("Unsupported type:" + targetType.FullName);
}
}
else
{
var readStream = await strategy.OpenReadStreamAsync();
onComplete = obj => Task.FromResult(0); // Nop
if (targetType == typeof(Stream))
{
userObj = readStream;
}
else if (targetType == typeof(TextReader))
{
userObj = new StreamReader(readStream);
}
else if (targetType == typeof(StreamReader))
{
userObj = new StreamReader(readStream);
}
else if (targetType == typeof(string))
{
userObj = new StreamReader(readStream).ReadToEnd();
}
else if (targetType == typeof(byte[]) && readStream is MemoryStream)
{
userObj = ((MemoryStream)readStream).ToArray();
}
else
{
throw new InvalidOperationException("Unsupported type:" + targetType.FullName);
}
}
valueProvider = new ConstantObj
{
Type = targetType,
Value = userObj,
OnCompleted = onComplete
};
return(valueProvider);
}