代碼編寫的過程中，較多的會涉及到基本數據類型的使用和定義，在項目中，對於類型的判定和類型間的相互轉換，有時也較為的麻煩，先提供幾種基本數據類型的判斷方法：
1.判斷對象是否為Int32類型的數字：
/// <summary>
/// 判斷對象是否為Int32類型的數字
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public static bool IsNumeric(object expression)
{
return expression != null && IsNumeric(expression.ToString());
}
/// <summary>
/// 判斷對象是否為Int32類型的數字
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public static bool IsNumeric(string expression)
{
var str = expression;
if (!(str.Length > 0) || str.Length > 11 || !System.Text.RegularExpressions.Regex.IsMatch(str, @"^[-]?[0-9]*[.]?[0-9]*$")) return false;
return (str.Length < 10) || (str.Length == 10 && str[0] == '1') ||
(str.Length == 11 && str[0] == '-' && str[1] == '1');
}
2.是否為Double類型：
/// <summary>
/// 是否為Double類型
/// </summary>
/// <param name="expression"></param>
/// <returns></returns>
public static bool IsDouble(object expression)
{
if (expression != null)
return System.Text.RegularExpressions.Regex.IsMatch(expression.ToString(), @"^([0-9])[0-9]*(\.\w*)?$");
return false;
}
3.將字符串轉換為數組：
/// <summary>
/// 將字符串轉換為數組
/// </summary>
/// <param name="str">字符串</param>
/// <returns>字符串數組</returns>
public static string[] GetStrArray(string str)
{
return str.Split(new char[',']);
}
4.將數組轉換為字符串：
/// <summary>
/// 將數組轉換為字符串
/// </summary>
/// <param name="list">List</param>
/// <param name="speater">分隔符</param>
/// <returns>String</returns>
public static string GetArrayStr(List<string> list, string speater)
{
var sb = new StringBuilder();
for (int i = 0; i < list.Count; i++)
{
if (i == list.Count - 1)
{
sb.Append(list[i]);
}
else
{
sb.Append(list[i]);
sb.Append(speater);
}
}
return sb.ToString();
}
5.object型轉換為bool型：
/// <summary>
/// object型轉換為bool型
/// </summary>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的bool類型結果</returns>
public static bool StrToBool(object expression, bool defValue)
{
if (expression != null)
return StrToBool(expression, defValue);
return defValue;
}
6.string型轉換為bool型：
/// <summary>
/// string型轉換為bool型
/// </summary>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的bool類型結果</returns>
public static bool StrToBool(string expression, bool defValue)
{
if (expression == null) return defValue;
if (string.Compare(expression, "true", StringComparison.OrdinalIgnoreCase) == 0)
return true;
return string.Compare(expression, "false", StringComparison.OrdinalIgnoreCase) != 0 && defValue;
}
7.將對象轉換為Int32類型：
/// <summary>
/// 將對象轉換為Int32類型
/// </summary>
/// <param name="expression">要轉換的字符串</param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static int ObjToInt(object expression, int defValue)
{
return expression != null ? StrToInt(expression.ToString(), defValue) : defValue;
}
8.將字符串轉換為Int32類型：
/// <summary>
/// 將字符串轉換為Int32類型
/// </summary>
/// <param name="expression">要轉換的字符串</param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static int StrToInt(string expression, int defValue)
{
if (string.IsNullOrEmpty(expression) || expression.Trim().Length >= 11 ||
!System.Text.RegularExpressions.Regex.IsMatch(expression.Trim(), @"^([-]|[0-9])[0-9]*(\.\w*)?$"))
return defValue;
int rv;
if (int.TryParse(expression, out rv))
return rv;
return Convert.ToInt32(StrToFloat(expression, defValue));
}
9.Object型轉換為decimal型：
/// <summary>
/// Object型轉換為decimal型
/// </summary>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的decimal類型結果</returns>
public static decimal ObjToDecimal(object expression, decimal defValue)
{
if (expression != null)
return StrToDecimal(expression.ToString(), defValue);
return defValue;
}
10.string型轉換為decimal型：
/// <summary>
/// string型轉換為decimal型
/// </summary>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的decimal類型結果</returns>
public static decimal StrToDecimal(string expression, decimal defValue)
{
if ((expression == null) || (expression.Length > 10))
return defValue;
decimal intValue = defValue;
{
bool isDecimal = System.Text.RegularExpressions.Regex.IsMatch(expression, @"^([-]|[0-9])[0-9]*(\.\w*)?$");
if (isDecimal)
decimal.TryParse(expression, out intValue);
}
return intValue;
}
11.Object型轉換為float型：
/// <summary>
/// Object型轉換為float型
/// </summary>
/// <param name="strValue">要轉換的字符串</param>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static float ObjToFloat(object expression, float defValue)
{
if (expression != null)
return StrToFloat(expression.ToString(), defValue);
return defValue;
}
12.string型轉換為float型：
/// <summary>
/// string型轉換為float型
/// </summary>
/// <param name="expression"></param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static float StrToFloat(string expression, float defValue)
{
if ((expression == null) || (expression.Length > 10))
return defValue;
float intValue = defValue;
{
bool isFloat = System.Text.RegularExpressions.Regex.IsMatch(expression, @"^([-]|[0-9])[0-9]*(\.\w*)?$");
if (isFloat)
float.TryParse(expression, out intValue);
}
return intValue;
}
13.將對象轉換為日期時間類型（提供幾種操作方法份的重載）：
/// <summary>
/// 將對象轉換為日期時間類型
/// </summary>
/// <param name="str">要轉換的字符串</param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static DateTime StrToDateTime(string str, DateTime defValue)
{
if (!string.IsNullOrEmpty(str))
{
DateTime dateTime;
if (DateTime.TryParse(str, out dateTime))
return dateTime;
}
return defValue;
}
/// <summary>
/// 將對象轉換為日期時間類型
/// </summary>
/// <param name="str">要轉換的字符串</param>
/// <returns>轉換後的int類型結果</returns>
public static DateTime StrToDateTime(string str)
{
return StrToDateTime(str, DateTime.Now);
}
/// <summary>
/// 將對象轉換為日期時間類型
/// </summary>
/// <param name="obj">要轉換的對象</param>
/// <returns>轉換後的int類型結果</returns>
public static DateTime ObjectToDateTime(object obj)
{
return StrToDateTime(obj.ToString());
}
/// <summary>
/// 將對象轉換為日期時間類型
/// </summary>
/// <param name="obj">要轉換的對象</param>
/// <param name="defValue">缺省值</param>
/// <returns>轉換後的int類型結果</returns>
public static DateTime ObjectToDateTime(object obj, DateTime defValue)
{
return StrToDateTime(obj.ToString(), defValue);
}
14.將對象轉換為字符串：
/// <summary>
/// 將對象轉換為字符串
/// </summary>
/// <param name="obj">要轉換的對象</param>
/// <returns>轉換後的string類型結果</returns>
public static string ObjectToStr(object obj)
{
if (obj == null)
return "";
return obj.ToString().Trim();
}
