public class DataTableHelper
{
/// <summary>
/// 给DataTable增加一个自增列
/// 如果DataTable 存在 identityid 字段 则 直接返回DataTable 不做任何处理
/// </summary>
/// <param name="dt">DataTable</param>
/// <returns>返回Datatable 增加字段 identityid </returns>
public static DataTable AddIdentityColumn(DataTable dt)
{
if (!dt.Columns.Contains("identityid"))
{
dt.Columns.Add("identityid");
for (int i = 0; i < dt.Rows.Count; i++)
{
dt.Rows[i]["identityid"] = (i + 1).ToString();
}
}
return dt;
} /// <summary>
/// 检查DataTable 是否有数据行
/// </summary>
/// <param name="dt">DataTable</param>
/// <returns></returns>
public static bool IsHaveRows(DataTable dt)
{
if (dt != null && dt.Rows.Count > 0)
return true; return false;
} /// <summary>
/// DataTable转换成实体列表
/// </summary>
/// <typeparam name="T">实体 T </typeparam>
/// <param name="table">datatable</param>
/// <returns></returns>
public static IList<T> DataTableToList<T>(DataTable table)
where T : class
{
if (!IsHaveRows(table))
return new List<T>(); IList<T> list = new List<T>();
T model = default(T);
foreach (DataRow dr in table.Rows)
{
model = Activator.CreateInstance<T>(); foreach (DataColumn dc in dr.Table.Columns)
{
object drValue = dr[dc.ColumnName];
PropertyInfo pi = model.GetType().GetProperty(dc.ColumnName); if (pi != null && pi.CanWrite && (drValue != null && !Convert.IsDBNull(drValue)))
{
pi.SetValue(model, drValue, null);
}
} list.Add(model);
}
return list;
} /// <summary>
/// 实体列表转换成DataTable
/// </summary>
/// <typeparam name="T">实体</typeparam>
/// <param name="list"> 实体列表</param>
/// <returns></returns>
public static DataTable ListToDataTable<T>(IList<T> list)
where T : class
{
if (list == null || list.Count <= 0)
{
return null;
}
DataTable dt = new DataTable(typeof(T).Name);
DataColumn column;
DataRow row; PropertyInfo[] myPropertyInfo = typeof(T).GetProperties(BindingFlags.Public | BindingFlags.Instance); int length = myPropertyInfo.Length;
bool createColumn = true; foreach (T t in list)
{
if (t == null)
{
continue;
} row = dt.NewRow();
for (int i = 0; i < length; i++)
{
PropertyInfo pi = myPropertyInfo[i];
string name = pi.Name;
if (createColumn)
{
column = new DataColumn(name, pi.PropertyType);
dt.Columns.Add(column);
} row[name] = pi.GetValue(t, null);
} if (createColumn)
{
createColumn = false;
} dt.Rows.Add(row);
}
return dt; } /// <summary>
/// 将泛型集合类转换成DataTable
/// </summary>
/// <typeparam name="T">集合项类型</typeparam>
/// <param name="list">集合</param>
/// <returns>数据集(表)</returns>
public static DataTable ToDataTable<T>(IList<T> list)
{
return ToDataTable<T>(list, null);
} /// <summary>
/// 将泛型集合类转换成DataTable
/// </summary>
/// <typeparam name="T">集合项类型</typeparam>
/// <param name="list">集合</param>
/// <param name="propertyName">需要返回的列的列名</param>
/// <returns>数据集(表)</returns>
public static DataTable ToDataTable<T>(IList<T> list, params string[] propertyName)
{
List<string> propertyNameList = new List<string>();
if (propertyName != null)
propertyNameList.AddRange(propertyName); DataTable result = new DataTable();
if (list.Count > 0)
{
PropertyInfo[] propertys = list[0].GetType().GetProperties();
foreach (PropertyInfo pi in propertys)
{
if (propertyNameList.Count == 0)
{
result.Columns.Add(pi.Name, pi.PropertyType);
}
else
{
if (propertyNameList.Contains(pi.Name))
{
result.Columns.Add(pi.Name, pi.PropertyType);
}
}
} for (int i = 0; i < list.Count; i++)
{
ArrayList tempList = new ArrayList();
foreach (PropertyInfo pi in propertys)
{
if (propertyNameList.Count == 0)
{
object obj = pi.GetValue(list[i], null);
tempList.Add(obj);
}
else
{
if (propertyNameList.Contains(pi.Name))
{
object obj = pi.GetValue(list[i], null);
tempList.Add(obj);
}
}
}
object[] array = tempList.ToArray();
result.LoadDataRow(array, true);
}
}
return result;
} /// <summary>
/// 根据nameList里面的字段创建一个表格,返回该表格的DataTable
/// </summary>
/// <param name="nameList">包含字段信息的列表</param>
/// <returns>DataTable</returns>
public static DataTable CreateTable(List<string> nameList)
{
if (nameList.Count <= 0)
return null; DataTable myDataTable = new DataTable();
myDataTable.TableName = "tableName";//增加一个默认的名字
foreach (string columnName in nameList)
{
myDataTable.Columns.Add(columnName, typeof(string));
}
return myDataTable;
} /// <summary>
/// 通过字符列表创建表字段，字段格式可以是：
/// 1) a,b,c,d,e
/// 2) a|int,b|string,c|bool,d|decimal
/// </summary>
/// <param name="nameString"></param>
/// <returns></returns>
public static DataTable CreateTable(string nameString)
{
string[] nameArray = nameString.Split(new char[] { ',', ';' });
List<string> nameList = new List<string>();
DataTable dt = new DataTable();
dt.TableName = "tableName";//增加一个默认的名字
foreach (string item in nameArray)
{
if (!string.IsNullOrEmpty(item))
{
string[] subItems = item.Split('|');
if (subItems.Length == 2)
{
dt.Columns.Add(subItems[0], ConvertType(subItems[1]));
}
else
{
dt.Columns.Add(subItems[0]);
}
}
}
return dt;
} private static Type ConvertType(string typeName)
{
typeName = typeName.ToLower().Replace("system.", "");
Type newType = typeof(string);
switch (typeName)
{
case "boolean":
case "bool":
newType = typeof(bool);
break;
case "int16":
case "short":
newType = typeof(short);
break;
case "int32":
case "int":
newType = typeof(int);
break;
case "long":
case "int64":
newType = typeof(long);
break;
case "uint16":
case "ushort":
newType = typeof(ushort);
break;
case "uint32":
case "uint":
newType = typeof(uint);
break;
case "uint64":
case "ulong":
newType = typeof(ulong);
break;
case "single":
case "float":
newType = typeof(float);
break; case "string":
newType = typeof(string);
break;
case "guid":
newType = typeof(Guid);
break;
case "decimal":
newType = typeof(decimal);
break;
case "double":
newType = typeof(double);
break;
case "datetime":
newType = typeof(DateTime);
break;
case "byte":
newType = typeof(byte);
break;
case "char":
newType = typeof(char);
break;
}
return newType;
} /// <summary>
/// 获得从DataRowCollection转换成的DataRow数组
/// </summary>
/// <param name="drc">DataRowCollection</param>
/// <returns></returns>
public static DataRow[] GetDataRowArray(DataRowCollection drc)
{
int count = drc.Count;
DataRow[] drs = new DataRow[count];
for (int i = 0; i < count; i++)
{
drs[i] = drc[i];
}
return drs;
} /// <summary>
/// 将DataRow数组转换成DataTable，注意行数组的每个元素须具有相同的数据结构，
/// 否则当有元素长度大于第一个元素时，抛出异常
/// </summary>
/// <param name="rows">行数组</param>
/// <returns></returns>
public static DataTable GetTableFromRows(DataRow[] rows)
{
if (rows.Length <= 0)
{
return new DataTable();
}
DataTable dt = rows[0].Table.Clone();
dt.DefaultView.Sort = rows[0].Table.DefaultView.Sort;
for (int i = 0; i < rows.Length; i++)
{
dt.LoadDataRow(rows[i].ItemArray, true);
}
return dt;
} /// <summary>
/// 排序表的视图
/// </summary>
/// <param name="dt"></param>
/// <param name="sorts"></param>
/// <returns></returns>
public static DataTable SortedTable(DataTable dt, params string[] sorts)
{
if (dt.Rows.Count > 0)
{
string tmp = "";
for (int i = 0; i < sorts.Length; i++)
{
tmp += sorts[i] + ",";
}
dt.DefaultView.Sort = tmp.TrimEnd(',');
}
return dt;
} /// <summary>
/// 根据条件过滤表的内容
/// </summary>
/// <param name="dt"></param>
/// <param name="condition"></param>
/// <returns></returns>
public static DataTable FilterDataTable(DataTable dt, string condition)
{
if (condition.Trim() == "")
{
return dt;
}
else
{
DataTable newdt = new DataTable();
newdt = dt.Clone();
DataRow[] dr = dt.Select(condition);
for (int i = 0; i < dr.Length; i++)
{
newdt.ImportRow((DataRow)dr[i]);
}
return newdt;
}
} /// <summary>
/// 转换.NET的Type到数据库参数的类型
/// </summary>
/// <param name="t"></param>
/// <returns></returns>
public static DbType TypeToDbType(Type t)
{
DbType dbt;
try
{
dbt = (DbType)Enum.Parse(typeof(DbType), t.Name);
}
catch
{
dbt = DbType.Object;
}
return dbt;
} /// <summary>
/// 使用分隔符串联表格字段的内容,如：a,b,c
/// </summary>
/// <param name="dt">表格</param>
/// <param name="columnName">字段名称</param>
/// <param name="append">增加的字符串，无则为空</param>
/// <param name="splitChar">分隔符，如逗号(,)</param>
/// <returns></returns>
public static string ConcatColumnValue(DataTable dt, string columnName, string append, char splitChar)
{
string result = append;
if (dt != null && dt.Rows.Count > 0)
{
foreach (DataRow row in dt.Rows)
{
result += string.Format("{0}{1}", splitChar, row[columnName]);
}
}
return result.Trim(splitChar);
} /// <summary>
/// 使用逗号串联表格字段的内容,如：a,b,c
/// </summary>
/// <param name="dt">表格</param>
/// <param name="columnName">字段名称</param>
/// <param name="append">增加的字符串，无则为空</param>
/// <returns></returns>
public static string ConcatColumnValue(DataTable dt, string columnName, string append)
{
string result = append;
if (dt != null && dt.Rows.Count > 0)
{
foreach (DataRow row in dt.Rows)
{
result += string.Format(",{0}", row[columnName]);
}
}
return result.Trim(',');
} /// <summary>
/// 判断表格是否包含指定的全部字段名称,如果其中一个不符合则返回false
/// </summary>
/// <param name="dt">表格对象</param>
/// <param name="columnString">字段列名称，逗号分开</param>
/// <returns></returns>
public static bool ContainAllColumns(DataTable dt, string columnString)
{
bool result = true;
if (dt != null && !string.IsNullOrEmpty(columnString))
{
List<string> columnList = columnString.Split(',').ToList();
foreach (string columnName in columnList)
{
if (!string.IsNullOrEmpty(columnName) && !dt.Columns.Contains(columnName))
{
result = false;
}
}
}
else
{
result = false;
}
return result;
}
}