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C# CsvReader.AssertNotNull方法代码示例

本文整理汇总了C#中CsvReader.AssertNotNull方法的典型用法代码示例。如果您正苦于以下问题:C# CsvReader.AssertNotNull方法的具体用法?C# CsvReader.AssertNotNull怎么用?C# CsvReader.AssertNotNull使用的例子?那么恭喜您, 这里精选的方法代码示例或许可以为您提供帮助。您也可以进一步了解该方法所在CsvReader的用法示例。


在下文中一共展示了CsvReader.AssertNotNull方法的1个代码示例,这些例子默认根据受欢迎程度排序。您可以为喜欢或者感觉有用的代码点赞,您的评价将有助于系统推荐出更棒的C#代码示例。

示例1: FillAsync

        /// <summary>
        /// Populates <paramref name="this"/> with data read asynchronously from <paramref name="csvReader"/>.
        /// </summary>
        /// <remarks>
        /// <para>
        /// If <paramref name="this"/> has columns defined, those columns will be used when populating the data. If no columns have been defined, <paramref name="csvReader"/> must have a
        /// <see cref="HeaderRecord"/>, which is then used to define the columns for <paramref name="this"/>. If any data record has more values than can fit into the columns defined on
        /// <paramref name="this"/>, an exception is thrown.
        /// </para>
        /// </remarks>
        /// <param name="this">
        /// The <see cref="DataTable"/>.
        /// </param>
        /// <param name="csvReader">
        /// The <see cref="CsvReader"/>.
        /// </param>
        /// <param name="maximumRecords">
        /// The maximum number of records to read and add to <paramref name="this"/>.
        /// </param>
        /// <returns>
        /// The number of rows added to <paramref name="this"/> (and therefore the number of data records read from <paramref name="csvReader"/>).
        /// </returns>
        public async static Task<int> FillAsync(this DataTable @this, CsvReader csvReader, int? maximumRecords)
        {
            @this.AssertNotNull("@this");
            csvReader.AssertNotNull("csvReader");
            exceptionHelper.ResolveAndThrowIf(maximumRecords.GetValueOrDefault() < 0, "maximumRecordsMustBePositive");

            if (@this.Columns.Count == 0)
            {
                // table has no columns, so we need to use the CSV header record to populate them
                exceptionHelper.ResolveAndThrowIf(csvReader.HeaderRecord == null, "noColumnsAndNoHeaderRecord");

                foreach (var columnName in csvReader.HeaderRecord)
                {
                    @this.Columns.Add(columnName);
                }
            }

            var remaining = maximumRecords.GetValueOrDefault(int.MaxValue);
            var buffer = new DataRecord[16];

            while (remaining > 0)
            {
                var read = await csvReader.ReadDataRecordsAsync(buffer, 0, Math.Min(buffer.Length, remaining)).ConfigureAwait(false);

                if (read == 0)
                {
                    // no more data
                    break;
                }

                for (var i = 0; i < read; ++i)
                {
                    var record = buffer[i];
                    exceptionHelper.ResolveAndThrowIf(record.Count > @this.Columns.Count, "moreValuesThanColumns", @this.Columns.Count, record.Count);

                    var recordAsStrings = new string[record.Count];
                    record.CopyTo(recordAsStrings, 0);
                    @this.Rows.Add(recordAsStrings);
                }

                remaining -= read;
            }

            return maximumRecords.GetValueOrDefault(int.MaxValue) - remaining;
        }
开发者ID:GitOffice,项目名称:DataPie,代码行数:67,代码来源:DataExtensions_Async.cs


注:本文中的CsvReader.AssertNotNull方法示例由纯净天空整理自Github/MSDocs等开源代码及文档管理平台,相关代码片段筛选自各路编程大神贡献的开源项目,源码版权归原作者所有,传播和使用请参考对应项目的License;未经允许,请勿转载。