/// <summary>
/// Executes the supplied query and calls the callback function for each row of result
/// </summary>
/// <remarks>
/// <p>
/// If the database is busy (ie with another process/thread using it) then
/// this method will call Thread.Sleep(), and then retry the query. Number of
/// retries and retry delay are configurable using the appropriate properties.</p>
/// <p>The result set object may be empty if there are no results, or if the
/// query does not return results (eg. UPDATE, INSERT, DELETE etc)</p>
/// </remarks>
/// <param name="query">The SQL query to execute</param>
/// <param name="callback">The callback function to call
/// (object Param, string[] ColumnNames, ArrayList Data)</param>
/// <param name="Param">A object to pass to the callback function</param>
/// <exception cref="SQLiteException">
/// Thrown if an error occurs or if the database is busy and the retries
/// are exhausted.
/// </exception>
public unsafe void Execute(string query, ResultCallBack callback, object Param)
{
column_names = null; //reset for each new query
param = Param;
callbackfunc = callback;
ResultCode errorCode;
string errorMsg;
int retries = 0;
using (SqliteString sql = new SqliteString(query))
{
while ((errorCode = SQLiteClient.sqlite3_exec(
this.dbHandle,
sql.ToPointer(),
(callbackfunc == null) ? null : new SQLiteCallback(CallBack),
IntPtr.Zero, out errorMsg))
== ResultCode.BUSY && retries < this.busyRetries)
{
Thread.Sleep(this.busyRetryDelay);
++retries;
continue;
}
if (errorCode != ResultCode.OK)
{
throw new SQLiteException(SQLiteClient.GetMessageForError(errorCode) + ":\n"
+ errorMsg + "\n the query string is :\n" + query, errorCode);
}
}
}
public async void Query(string database, string sql, ResultCallBack resultCallBack)
{
List <Serie> series = await _client.QueryAsync(database, sql);
string result = Newtonsoft.Json.JsonConvert.SerializeObject(series);
resultCallBack?.Invoke(result);
}
public async void GetDatabases(ResultCallBack resultCallBack)
{
List <Database> databases = await _client.ShowDatabasesAsync();
string result = Newtonsoft.Json.JsonConvert.SerializeObject(databases);
resultCallBack?.Invoke(result);
}
private ResultCallBack resultcallback; //实例化回调方法
#endregion Fields
#region Constructors
/// <summary>
/// 构造函数
/// </summary>
/// <param name="info">邮件信息</param>
/// <param name="reinfo">邮件记录</param>
/// <param name="resultcallback">回调函数</param>
public AsynEmail(EmailInfo info,EmailRecordInfo reinfo,ResultCallBack resultcallback)
{
this.Info = info;
this.resultcallback = resultcallback;
this.ReInfo = reinfo;
}
/// <summary>
/// 构造函数
/// </summary>
/// <param name="info">邮件信息</param>
/// <param name="reinfo">邮件记录</param>
/// <param name="resultcallback">回调函数</param>
public AsynEmail(EmailInfo info, EmailRecordInfo reinfo, ResultCallBack resultcallback)
{
this.Info = info;
this.resultcallback = resultcallback;
this.ReInfo = reinfo;
}
public void setCallBack(byte resultType, ResultCallBack callback)
{
callbacks[resultType] = callback;
}
