学用 ASP.Net 之 "字符串" (3): string 类的非扩展方法

string 类的非扩展成员:

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/* 类方法 */

string.Compare;            //对比, 返回 1、0 或 -1

string.CompareOrdinal;     //对比, 返回序号差

string.Concat;             //合并

string.Copy;               //复制

string.Equals;             //是否同值

string.Format;             //格式化输出

string.Intern;             //

string.IsInterned;         //

string.IsNullOrEmpty;      //是否是 null 或 Empty

string.IsNullOrWhiteSpace; //是否是 null 或 Empty 或空白字符

string.Join;               //连接

string.ReferenceEquals;    //是否是相同的实例, 继承自 Object



/* 变量 */

string.Empty; // 空字符串, 同 ""



/* 属性 */

Length;       //



/* 对象方法 */

Clone;            //引用

CompareTo;        //

Contains;         //是否包含

CopyTo;           //复制部分到字符数组

EndsWith;         //尾匹配

Equals;           //是否同值

GetEnumerator;    //获取枚举器

GetHashCode;      //

GetType;          //

GetTypeCode;      //

IndexOf;          //查找

IndexOfAny;       //根据字符数组查找

Insert;           //插入

IsNormalized;     //

LastIndexOf;      //从右边开始查找

LastIndexOfAny;   //根据字符数组从右边开始查找

Normalize;        //

PadLeft;          //从左边添加空格或其它字符

PadRight;         //从右边添加空格或其它字符

Remove;           //移除

Replace;          //替换

Split;            //分割

StartsWith;       //首匹配

Substring;        //截取

ToLower;          //转小写

ToLowerInvariant; //转小写, 使用区域大小写规则

ToString;         //

ToUpper;          //转大写

ToUpperInvariant; //转大写, 使用区域大小写规则

Trim;             //删左右空白

TrimEnd;          //删右空白

TrimStart;        //删左空白

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大小写转换:

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protected void Button1_Click(object sender, EventArgs e)

{

    TextBox1.TextMode = TextBoxMode.MultiLine;



    string str = "Asp.Net", s1, s2, s3, s4;

    s1 = str.ToUpper();          //ASP.NET

    s2 = str.ToUpperInvariant(); //ASP.NET

    s3 = str.ToLower();          //asp.net

    s4 = str.ToLowerInvariant(); //asp.net

    TextBox1.Text = string.Concat(s1 + "\n" + s2 + "\n" + s3 + "\n" + s4);

}

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添加或删除空白:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str, s1, s2, s3, s4, s5, s6, s7, r = "\n";

    str = "Asp";

    s1 = '>' + str.PadLeft(str.Length + 4) + '<';  //>    Asp<

    s2 = '>' + str.PadRight(str.Length + 4) + '<'; //>Asp    <

    s3 = '>' + str.PadLeft(7, '*') + '<';          //>****Asp<

    s4 = '>' + str.PadRight(7, '*') + '<';         //>Asp****<



    str = "    Asp    ";

    s5 = '>' + str.TrimStart() + '<'; //>Asp    <

    s6 = '>' + str.TrimEnd() + '<';   //>    Asp<

    s7 = '>' + str.Trim() + '<';      //>Asp<

    TextBox1.Text = string.Concat(s1 + r + s2 + r + s3 + r + s4 + r + s5 + r + s6 + r + s7);

}

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截取:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str, s1, s2, r = "\n";

    str = "123456789";

    s1 = str.Substring(2);    //3456789

    s2 = str.Substring(2, 4); //3456

    TextBox1.Text = string.Concat(s1 + r + s2);

}

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分割:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str, r = "\n";

    str = "1:2-3|4:5-6||7:8-9";



    string[] arr1 = str.Split('|');

    TextBox1.Text += string.Join(" / ", arr1) + r; //1:2-3 / 4:5-6 /  / 7:8-9 /



    string[] arr2 = str.Split('|', ':');

    TextBox1.Text += string.Join(" / ", arr2) + r; //1 / 2-3 / 4 / 5-6 /  / 7 / 8-9 / 



    string[] arr3 = str.Split('|', ':', '-');

    TextBox1.Text += string.Join(" / ", arr3) + r; //1 / 2 / 3 / 4 / 5 / 6 /  / 7 / 8 / 9 / 



    string[] arr4 = str.Split(new char[] { '|', ':', '-' });

    TextBox1.Text += string.Join(" / ", arr4) + r; //1 / 2 / 3 / 4 / 5 / 6 /  / 7 / 8 / 9 / 



    char[] cs = { '|', ':', '-' };



    string[] arr5 = str.Split(cs);

    TextBox1.Text += string.Join(" / ", arr5) + r; //1 / 2 / 3 / 4 / 5 / 6 /  / 7 / 8 / 9 / 



    string[] arr6 = str.Split(cs, 3);

    TextBox1.Text += string.Join(" / ", arr6) + r; //1 / 2 / 3|4:5-6||7:8-9 / 



    string[] arr7 = str.Split(cs, StringSplitOptions.RemoveEmptyEntries);

    TextBox1.Text += string.Join(" / ", arr7) + r; //1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 



    string[] arr8 = str.Split(cs, int.MaxValue, StringSplitOptions.RemoveEmptyEntries);

    TextBox1.Text += string.Join(" / ", arr8) + r; //1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 



    string[] arr9 = str.Split(new char[] { '|' }, StringSplitOptions.RemoveEmptyEntries);

    TextBox1.Text += string.Join(" / ", arr9) + r; //1:2-3 / 4:5-6 / 7:8-9 / 

}

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替换:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str, r = "\n", s1, s2;

    str = "Asp.Net 3.5";

    s1 = str.Replace('.', '-');     //Asp-Net 3-5

    s2 = str.Replace("3.5", "4.0"); //Asp.Net 4.0



    TextBox1.Text = string.Concat(s1, r, s2);

}

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插入与移除:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str, r = "\n", s1, s2, s3;

    str = "Asp 3.5";

    s1 = str.Insert(3, ".Net"); //Asp.Net 3.5

    s2 = str.Remove(3);         //Asp

    s3 = str.Remove(0, 4);      //3.5



    TextBox1.Text = string.Concat(s1, r, s2, r, s3);

}

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查找:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str = "Asp.Net 3.5";

    int n1, n2, n3, n4, n5, n6, n7;



    n1 = str.IndexOf('.');     //3

    n2 = str.LastIndexOf('.'); //9

    n3 = str.IndexOf('.', 4);  //9

    n4 = str.IndexOf("NET");   //-1

    n5 = str.IndexOf("NET", StringComparison.CurrentCultureIgnoreCase); //4



    n6 = str.IndexOfAny(new char[] {'3', '5'});       //8

    n7 = str.LastIndexOfAny(new char[] { '3', '5' }); //10



    TextBox1.Text = string.Format("{0}\n{1}\n{2}\n{3}\n{4}\n{5}\n{6}", n1, n2, n3, n4, n5, n6, n7);

}

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是否包含:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str = "Asp.Net 3.5";

    bool b1, b2, b3;



    b1 = str.Contains('S');   //False

    b2 = str.Contains('s');   //True

    b3 = str.Contains("Net"); //True



    TextBox1.Text = string.Format("{0}\n{1}\n{2}", b1, b2, b3);

}

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首尾匹配:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str = "Asp.Net 3.5";

    bool b1, b2, b3, b4;



    b1 = str.StartsWith("asp");             //False

    b2 = str.StartsWith("asp", StringComparison.CurrentCultureIgnoreCase); //True

    b3 = str.StartsWith("asp", true, null); //True



    b4 = str.EndsWith("5");                 //True



    TextBox1.Text = string.Format("{0}\n{1}\n{2}\n{3}", b1, b2, b3, b4);

}

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对比:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str1 = "1001ABC";

    string str2 = "1001abc";

    int n1, n2, n3, n4, n5, n6, n7, n8, n9, n0;



    n1 = str1.CompareTo(str2); // 1

    n2 = str2.CompareTo(str1); //-1

    n3 = str1.CompareTo(str1); // 0



    n4 = string.Compare(str1, str2);          // 1

    n5 = string.Compare(str2, str1);          //-1

    n6 = string.Compare(str1, str2, true);    // 0

    n7 = string.Compare(str1, 0, str2, 0, 4); // 0



    n8 = string.CompareOrdinal(str1, str2);          //-32

    n9 = string.CompareOrdinal(str2, str1);          // 32

    n0 = string.CompareOrdinal(str1, 0, str2, 0, 4); // 0



    TextBox1.Text = string.Format("{0}\n{1}\n{2}\n{3}\n{4}\n{5}\n{6}\n{7}\n{8}\n{9}", n1, n2, n3, n4, n5, n6, n7, n8, n9, n0);

}

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是否相同:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str1 = "Asp.Net", str2 = "ASP.NET";

    bool b1, b2, b3, b4, b5, b6, b7;



    b1 = string.Equals(str1, str2);          //False

    b2 = string.Equals(str1, str2, StringComparison.CurrentCultureIgnoreCase); //True

    b3 = str1.Equals(str2);                  //False

    b4 = str1.Equals(str2, StringComparison.CurrentCultureIgnoreCase);         //True



    string str3 = str1;

    b5 = string.ReferenceEquals(str1, str3); //True



    str1 = str1.ToLower();

    str2 = str2.ToLower();

    b6 = str1 == str2;                       //True

    b7 = string.ReferenceEquals(str1, str2); //False



    TextBox1.Text = string.Format("{0}\n{1}\n{2}\n{3}\n{4}\n{5}\n{6}", b1, b2, b3, b4, b5, b6, b7);

}

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复制与引用:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str1 = "abc";

    string str2 = string.Copy(str1);

    string str3 = (string)str1.Clone();



    bool b1 = string.ReferenceEquals(str1, str2); //False

    bool b2 = string.ReferenceEquals(str1, str3); //True



    TextBox1.Text = string.Format("{0}\n{1}", b1, b2);

}

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复制部分到字符数组:

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protected void Button1_Click(object sender, EventArgs e)

{

    char[] cs = { '1', '2', '3', '4', '5', '6', '7', '8', '9' };

    string str = "ABCDEFG";



    str.CopyTo(1, cs, 3, 2);

    TextBox1.Text = string.Join("", cs); // 123BC6789

}

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是否为空:

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protected void Button1_Click(object sender, EventArgs e)

{

    bool b1, b2, b3, b4, b5;



    b1 = string.IsNullOrEmpty(null);         //True

    b2 = string.IsNullOrEmpty(string.Empty); //True

    b3 = string.IsNullOrEmpty("");           //True

    b4 = string.IsNullOrWhiteSpace("   ");   //True

    b5 = string.IsNullOrWhiteSpace("123");   //False



    TextBox1.Text = string.Format("{0}\n{1}\n{2}\n{3}\n{4}", b1, b2, b3, b4, b5);

}

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枚举器:

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protected void Button1_Click(object sender, EventArgs e)

{

    // 需 using System.Collections;

    string str = "Asp.Net 3.5";

    IEnumerator Enum = str.GetEnumerator();

    while (Enum.MoveNext()) 

    {

        TextBox1.Text += string.Format("{0}|", Enum.Current); //A|s|p|.|N|e|t| |3|.|5|

    }

}

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连接与串联:

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protected void Button1_Click(object sender, EventArgs e)

{

    string str;

    str = string.Concat("Asp", '.', "Net", "\x20", 3, '.', 5); //Asp.Net 3.5

    TextBox1.Text += str + "\n";



    int[] nArr = { 1, 3, 2, 4, 3, 5 };

    str = string.Join("*", nArr); //1*3*2*4*3*5

    TextBox1.Text += str + "\n";



    str = "Asp.Net";

    str = string.Join("|", str.ToArray()); //A|s|p|.|N|e|t

    TextBox1.Text += str + "\n";



    string[] sArr = { "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten" };

    str = string.Join("; ", sArr, 1, 3);   //two; three; four

    TextBox1.Text += str + "\n"; 

}

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