///
/// 扩展方法类
///
public static class CommonExtension
{
///
/// 数据类型对应转换方法字典
///
static Dictionaryobject, object>> dic_convert = new Dictionaryobject, object>>();
///
/// 构造函数
///
static CommonExtension()
{
Funcobject, object> f = null;
//string
f = (val) => Convert.ToString(val);
dic_convert.Add(typeof(string), f);
//int
f = (val) => Convert.ToInt32(val);
dic_convert.Add(typeof(int), f);
//long
f = (val) => Convert.ToInt64(val);
dic_convert.Add(typeof(long), f);
//double
f = (val) => Convert.ToDouble(val);
dic_convert.Add(typeof(double), f);
//float
f = (val) => (float)(val);
dic_convert.Add(typeof(float), f);
//decimal
f = (val) => Convert.ToDecimal(val);
dic_convert.Add(typeof(decimal), f);
//datetime
f = (val) => Convert.ToDateTime(val);
dic_convert.Add(typeof(DateTime), f);
//bool
f = (val) => Convert.ToBoolean(val);
dic_convert.Add(typeof(bool), f);
//byte
f = (val) => Convert.ToByte(val);
dic_convert.Add(typeof(byte), f);
//char
f = (val) => Convert.ToChar(val);
dic_convert.Add(typeof(char), f);
//null
f = (val) => (null);
dic_convert.Add(typeof(DBNull), f);
}
///
/// 获取DataTable的列名集合
///
public static IListstring> GetColumnNames(this DataTable dt)
{
if (dt == null || dt.Rows.Count == 0)
{
return new Liststring>(0);
}
//由于集合中的元素是确定的，所以可以指定元素的个数，系统就不会分配多余的空间，效率会高点
IListstring> list = new Liststring>(dt.Columns.Count);
foreach (DataColumn dc in dt.Columns)
{
list.Add(dc.ColumnName);
}
return list;
}
///
/// 将 DataTable 序列化成 json 字符串
///
///
///
public static string ToJson(this DataTable dt)
{
if (dt == null || dt.Rows.Count == 0)
{
return "[]";
}
JavaScriptSerializer myJson = new JavaScriptSerializer();
Liststring, object>> list = new Liststring, object>>();
foreach (DataRow dr in dt.Rows)
{
Dictionarystring, object> result = new Dictionarystring, object>();
foreach (DataColumn dc in dt.Columns)
{
result.Add(dc.ColumnName, dr[dc].ToString());
}
list.Add(result);
}
return myJson.Serialize(list);
}
///
/// 将 DataTable 序列化成 ArrayList
///
///
///
public static ArrayList ToArrayList(this DataTable dt)
{
ArrayList arrayList = new ArrayList();
if (dt != null)
{
foreach (DataRow dataRow in dt.Rows)
{
Dictionarystring, object> dictionary = new Dictionarystring, object>(); //实例化一个参数集合
foreach (DataColumn dataColumn in dt.Columns)
{
dictionary.Add(dataColumn.ColumnName, dataRow[dataColumn.ColumnName].ToString());
}
arrayList.Add(dictionary);
}
}
return arrayList;
}
///
/// 把DataTable转换成泛型列表
///
/// 类型
///
///
public static List ToList(this DataTable dt) where T : new()
{
var list = new List();
if (dt == null || dt.Rows.Count == 0)
{
return list;
}
// 获得此模型的公共属性
var plist = new List(typeof(T).GetProperties());
// 循环行
foreach (DataRow row in dt.Rows)
{
var t = new T();
// 循环列
foreach (DataColumn dc in dt.Columns)
{
var value = row[dc.ColumnName];
// 判断值是否有效
if (Convert.IsDBNull(value))
continue;
//var p = info.GetType().GetProperty(dc.ColumnName);
var p = plist.FirstOrDefault(c => c.Name.Equals(dc.ColumnName, StringComparison.CurrentCultureIgnoreCase));
// 判断此属性是否有Setter
if (p == null || !p.CanWrite)
continue;
if (dic_convert.ContainsKey(p.PropertyType))
{
var val = dic_convert[p.PropertyType].Invoke(value);
p.SetValue(t, val, null);
}
}
list.Add(t);
}
dt.Dispose();
dt = null;
return list;
}
///
/// 将DataTable实例转换成List
///
/// Model类型列表
/// DataTable对象
///
public static List ToListSmart(this DataTable dt) where T : new()
{
// 定义集合
List list = new List();
if (dt == null || dt.Rows.Count == 0)
{
return list;
}
// 获得此模型的类型
Type type = typeof(T);
// 获得此模型的公共属性
var plist = new List(type.GetProperties());
// 获取列的个数
int col_cnt = dt.Columns.Count;
T t;
if (plist.Count >= col_cnt)
{
#region 循环列给属性赋值方式
foreach (DataRow row in dt.Rows)
{
t = new T();
// 循环列
foreach (DataColumn dc in dt.Columns)
{
// 根据列名查找属性
PropertyInfo pi = plist.Find(p => p.Name.Equals(dc.ColumnName, StringComparison.CurrentCultureIgnoreCase));
if (pi != null)
{
// 判断此属性是否有Setter
if (!pi.CanWrite)
continue;
// 判断值是否有效
if (Convert.IsDBNull(row[pi.Name]))
continue;
if (dic_convert.ContainsKey(pi.PropertyType))
{
var val = dic_convert[pi.PropertyType].Invoke(row[pi.Name]);
pi.SetValue(t, val, null);
}
}
}
list.Add(t);
}
#endregion
}
else
{
#region 循环属性查找列对应的值
foreach (DataRow row in dt.Rows)
{
t = System.Activator.CreateInstance();
// 循环属性列表
foreach (PropertyInfo pi in plist)
{
// 检查DataTable是否包含此列
if (dt.Columns.Contains(pi.Name))
{
// 判断此属性是否有Setter
if (!pi.CanWrite)
continue;
// 判断值是否有效
if (row[pi.Name] == DBNull.Value)
continue;
if (dic_convert.ContainsKey(pi.PropertyType))
{
var val = dic_convert[pi.PropertyType].Invoke(row[pi.Name]);
pi.SetValue(t, val, null);
}
}
}
list.Add(t);
}
#endregion
}
return list;
}
#endregion
}
