Interface ITaskHandler
Used to run and track ITasks and ask the user questions. Specific implementations provide different kinds of user interfaces.
Namespace: NanoByte.Common.Tasks
Assembly: NanoByte.Common.dll
Syntax
public interface ITaskHandler
Remarks
Implementations of this interface are thread-safe.
Properties
CancellationToken
Used to signal when the user wants to cancel the entire current process (and any ITasks it includes).
Declaration
CancellationToken CancellationToken { get; }
Property Value
Type | Description |
---|---|
CancellationToken |
Remarks
Once this has been signalled this ITaskHandler cannot be reused, since any subsequently started ITasks will be cancelled immediately.
Verbosity
The detail level of messages displayed to the user.
Declaration
Verbosity Verbosity { get; set; }
Property Value
Type | Description |
---|---|
Verbosity |
Methods
Ask(String, Nullable<Boolean>, String)
Asks the user a Yes/No/Cancel question.
Declaration
bool Ask(string question, Nullable<bool> defaultAnswer = null, string alternateMessage = null)
Parameters
Type | Name | Description |
---|---|---|
String | question | The question and comprehensive information to help the user make an informed decision. |
Nullable<Boolean> | defaultAnswer | The default answer to preselect. May be chosen automatically if the user cannot be asked. |
String | alternateMessage | A message to output with Warn(String, Exception) when the |
Returns
Type | Description |
---|---|
Boolean |
|
Exceptions
Type | Condition |
---|---|
System.OperationCanceledException | Throw if the user answered with 'Cancel' or if no answer can be obtained. |
Error(Exception)
Displays an error message to the user.
Declaration
void Error(Exception exception)
Parameters
Type | Name | Description |
---|---|---|
Exception | exception | The exception representing the error that occurred. |
Output(String, String)
Displays multi-line text to the user.
Declaration
void Output(string title, string message)
Parameters
Type | Name | Description |
---|---|---|
String | title | A title for the message. |
String | message | The string to display. Trailing linebreaks are appropriately handled or ignored. |
Remarks
Implementations may close the UI as a side effect. Therefore this should be your last call on the handler.
Output<T>(String, NamedCollection<T>)
Displays tree-like data to the user.
Declaration
void Output<T>(string title, NamedCollection<T> data)
where T : INamed
Parameters
Type | Name | Description |
---|---|---|
String | title | A title for the data.INamed |
NamedCollection<T> | data | The data to display. |
Type Parameters
Name | Description |
---|---|
T |
Remarks
Implementations may close the UI as a side effect. Therefore this should be your last call on the handler.
Output<T>(String, IEnumerable<T>)
Displays tabular data to the user.
Declaration
void Output<T>(string title, IEnumerable<T> data)
Parameters
Type | Name | Description |
---|---|---|
String | title | A title for the data. |
IEnumerable<T> | data | The data to display. |
Type Parameters
Name | Description |
---|---|
T |
Remarks
Implementations may close the UI as a side effect. Therefore this should be your last call on the handler.
RunTask(ITask)
Runs an ITask and tracks its progress. Returns once the task has been completed.
Declaration
void RunTask(ITask task)
Parameters
Type | Name | Description |
---|---|---|
ITask | task | The task to be run. (Run(CancellationToken, ICredentialProvider, IProgress<TaskSnapshot>) or equivalent is called on it.) |
Exceptions
Type | Condition |
---|---|
System.OperationCanceledException | The user canceled the task. |
IOException | The task ended with IOError. |
WebException | The task ended with WebError. |