StorageFolder.CreateFileAsync Method
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| CreateFileAsync(String) |
Creates a new file with the specified name in the current folder. |
| CreateFileAsync(String, CreationCollisionOption) |
Creates a new file in the current folder. This method also specifies what to do if a file with the same name already exists in the current folder. |
Creates a new file with the specified name in the current folder.
public:
virtual IAsyncOperation<StorageFile ^> ^ CreateFileAsync(Platform::String ^ desiredName) = CreateFileAsync;/// [Windows.Foundation.Metadata.Overload("CreateFileAsyncOverloadDefaultOptions")]
/// [Windows.Foundation.Metadata.RemoteAsync]
IAsyncOperation<StorageFile> CreateFileAsync(winrt::hstring const& desiredName);[Windows.Foundation.Metadata.Overload("CreateFileAsyncOverloadDefaultOptions")]
[Windows.Foundation.Metadata.RemoteAsync]
public IAsyncOperation<StorageFile> CreateFileAsync(string desiredName);function createFileAsync(desiredName)Public Function CreateFileAsync (desiredName As String) As IAsyncOperation(Of StorageFile)Parameters
- desiredName
-
String
Platform::String
winrt::hstring
The name of the new file to create in the current folder.
Returns
When this method completes, it returns a StorageFile that represents the new file.
Implements
- Attributes
Exceptions
The file name contains invalid characters, or the format of the filename is incorrect. Check the value of desiredName.
You don't have permission to create a file in the current folder.
Examples
The following example shows how to create a new file in the current folder by calling the CreateFileAsync (String, CreationCollisionOption) overloaded method. This example explicitly specifies a value for options that causes the operation to fail if a file with the specified desiredName already exists in the current folder.
using Windows.Storage;
using System.Threading.Tasks;
// Get the app's local folder.
StorageFolder localFolder = Windows.Storage.ApplicationData.Current.LocalFolder;
// Create a new file in the current folder.
// Raise an exception if the file already exists.
string desiredName = "test.txt";
StorageFile newFile = await localFolder.CreateFileAsync(desiredName, CreationCollisionOption.FailIfExists);
IAsyncAction MainPage::ExampleCoroutineAsync()
{
// Gets the app's local folder.
Windows::Storage::StorageFolder localFolder{ Windows::Storage::ApplicationData::Current().LocalFolder() };
// Create a new file in the current folder, and throw an exception if the file already exists.
std::wstring desiredName{ L"test.txt" };
StorageFile newFile{ co_await localFolder.CreateFileAsync(desiredName, Windows::Storage::CreationCollisionOption::FailIfExists) };
// Do something with the new file.
}
//Gets the app's local folder
StorageFolder^ localFolder = ApplicationData::Current->LocalFolder;
//Create a new file in the current folder
// Raise an exception if the file already exists
String^ desiredName = "test.txt";
auto createFileTask = create_task(localFolder->CreateFileAsync(desiredName, Windows::Storage::CreationCollisionOption::FailIfExists));
createFileTask.then([](StorageFile^ newFile)
{
//Do something with the new file.
});
Remarks
This method uses the FailIfExists value from the CreationCollisionOption enumeration by default. That is, this method raises an exception if a file with the same name already exists in the current folder. If you want to handle a file name collision in a different way, call the CreateFileAsync(String, CreationCollisionOption) method.
If you try to create a file in a virtual folder like a library, or a folder that represents a container for a group of files (for example, the return value from some overloads of the GetFoldersAsync method), the CreateFileAsync method may fail.
See also
Applies to
Creates a new file in the current folder. This method also specifies what to do if a file with the same name already exists in the current folder.
public:
virtual IAsyncOperation<StorageFile ^> ^ CreateFileAsync(Platform::String ^ desiredName, CreationCollisionOption options) = CreateFileAsync;/// [Windows.Foundation.Metadata.Overload("CreateFileAsync")]
/// [Windows.Foundation.Metadata.RemoteAsync]
IAsyncOperation<StorageFile> CreateFileAsync(winrt::hstring const& desiredName, CreationCollisionOption const& options);[Windows.Foundation.Metadata.Overload("CreateFileAsync")]
[Windows.Foundation.Metadata.RemoteAsync]
public IAsyncOperation<StorageFile> CreateFileAsync(string desiredName, CreationCollisionOption options);function createFileAsync(desiredName, options)Public Function CreateFileAsync (desiredName As String, options As CreationCollisionOption) As IAsyncOperation(Of StorageFile)Parameters
- desiredName
-
String
Platform::String
winrt::hstring
The name of the new file to create in the current folder.
- options
- CreationCollisionOption
One of the enumeration values that determines how to handle the collision if a file with the specified desiredName already exists in the current folder.
Returns
When this method completes, it returns a StorageFile that represents the new file.
Implements
- Attributes
Exceptions
You specified CreationCollisionOption.FailIfExists and a file with the specified desiredName already exists in the current folder.
The format of the filename is incorrect. Check the value of desiredName.
You don't have permission to create a file in the current folder.