Class DataRowExtensions

DataRow 扩展方法

Inheritance

Object

DataRowExtensions

Inherited Members

Object.Equals(Object)

Object.Equals(Object, Object)

Object.GetHashCode()

Object.GetType()

Object.MemberwiseClone()

Object.ReferenceEquals(Object, Object)

Object.ToString()

Namespace: Lett.Extensions

Assembly: Lett.Extensions.dll

Syntax

public static class DataRowExtensions

Methods

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Cell<T>(DataRow, String)

获取当前行中某个列的值

Declaration

public static T Cell<T>(this DataRow this, string columnName)
    where T : IConvertible

Parameters

Type	Name	Description
DataRow	this
String	columnName	列名

Returns

Type	Description
T	`columnName`不存在或转换失败，返回 default(`T`)

Type Parameters

Name	Description
T	目标类型，约束为 IConvertible

Examples

var rs = dataRow.Cell<string>("columnName"); // if fail return default(string)

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Cell<T>(DataRow, String, T)

获取当前行中某个列的值

Declaration

public static T Cell<T>(this DataRow this, string columnName, T defaultValue)
    where T : IConvertible

Parameters

Type	Name	Description
DataRow	this
String	columnName	列名
T	defaultValue	默认值

Returns

Type	Description
T	`columnName`不存在或转换失败，返回 `defaultValue`

Type Parameters

Name	Description
T	目标类型，约束为 IConvertible

Examples

var rs = dataRow.Cell("columnName", "abc"); // if fail return "abc"

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Cell<T>(DataRow, String, Func<T>)

获取当前行中某个列的值

Declaration

public static T Cell<T>(this DataRow this, string columnName, Func<T> func)
    where T : IConvertible

Parameters

Type	Name	Description
DataRow	this
String	columnName	列名
Func<T>	func

Returns

Type	Description
T	`columnName`不存在或转换失败，返回 `func`

Type Parameters

Name	Description
T	目标类型，约束为 IConvertible

Examples

var rs = dataRow.Cell<string>("columnName", () => "func return value");

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HasColumn(DataRow, String)

列是否存在

Declaration

public static bool HasColumn(this DataRow this, string columnName)

Parameters

Type	Name	Description
DataRow	this
String	columnName	列名

Returns

Type	Description
Boolean

Examples

row.HasColumn("FRowId");

Exceptions

Type	Condition
ArgumentNullException	columnName is null or empty
ArgumentException

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SetValue<T>(DataRow, String, T)

设置值

出现异常时，使用 DBNull.Value 进行填充

Declaration

public static void SetValue<T>(this DataRow this, string columnName, T value)

Parameters

Type	Name	Description
DataRow	this
String	columnName
T	value

Type Parameters

Name	Description
T

Examples

row.SetValue("FColumnName", "value");
// if column "FColumnName" type is bool, row["FColumnName"] is DBNull.Value

Exceptions

Type	Condition
ArgumentNullException	`columnName` is null
ArgumentNullException	`T` is null
ArgumentException	`columnName` not exist

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SetValue<T>(DataRow, String, T, Boolean)

设置值

Declaration

public static void SetValue<T>(this DataRow this, string columnName, T value, bool isDefaultDbNull)

Parameters

Type	Name	Description
DataRow	this
String	columnName	列名
T	value	值
Boolean	isDefaultDbNull	赋值出现异常时，是否使用 `DBNull.Value` 进行填充

Type Parameters

Name	Description
T

Examples

row.SetValue("FColumnName", "value", true);
// if column "FColumnName" type is bool, row["FColumnName"] is DBNull.Value

Exceptions

Type	Condition
ArgumentNullException	`columnName` is null
ArgumentNullException	`T` is null
ArgumentException	`columnName` not exist

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ToDynamicObject(DataRow)

转换为动态对象集合

值为 Value 转换为 Null

Declaration

public static dynamic ToDynamicObject(this DataRow this)

Parameters

Type	Name	Description
DataRow	this

Returns

Type	Description
Object	如果Cell为 Value 则动态对象属性的值为 null

Examples

var dt = new DataTable();
dt.Columns.Add("col1", typeof(string));
dt.Columns.Add("col2", typeof(DateTime));
dt.Columns.Add("col3", typeof(decimal));
dt.Columns.Add("col4", typeof(string));
dt.Columns.Add("col5", typeof(string));
dt.Rows.Add("strVal", new DateTime(2019, 4, 1), 100.23m, DBNull.Value, null);
var rs = dt.Rows[0].ToDynamicObject();

// rs.col1 == "strVal"
// rs.col2 == new DateTime(2019, 4, 1)
// rs.col3 == 100.23m
// rs.col4 is null
// rs.col5 is null

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ToEntity<T>(DataRow)

转换为实体

使用DataRow中的值，填充目标类型的 FieldInfo 与 PropertyInfo

匹配规则: FieldInfo.Name 或 PropertyInfo.Name 与 ColumnName 相同

Declaration

public static T ToEntity<T>(this DataRow this)
    where T : class, new()

Parameters

Type	Name	Description
DataRow	this

Returns

Type	Description
T	目标对象 `T`

Type Parameters

Name	Description
T	目标类型

Examples

dataTable.Rows[0].ToEntity<TestClass1>();

Exceptions

Type	Condition
FieldAccessException
TargetException
ArgumentException
MethodAccessException
TargetInvocationException

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ToEntity<T>(DataRow, Func<DataRow, T, T>)

转换为实体

Declaration

public static T ToEntity<T>(this DataRow this, Func<DataRow, T, T> converter)
    where T : class, new()

Parameters

Type	Name	Description
DataRow	this
Func<DataRow, T, T>	converter	参数 DataRow: 当前行参数 `T`: 目标新实例

Returns

Type	Description
T	目标对象 `T`

Type Parameters

Name	Description
T	目标类型

Examples

var rs = dt.Rows[0].ToEntity<TestClass1>((row, newClass) =>
{
newClass.Property1    = row.Cell<string>("Property1");
newClass.PublicField1 = row.Cell<string>("PublicField1");
return newClass;
});