没有区别。 Convert.ToInt32()在内部调用int.Parse()

除了一件事Convert.ToInt32()当参数为空时返回0

否则两者的工作方式是一样的

Convert.ToInt32

有19种重载或者19种不同的调用方式。2010年的版本可能会更多。

它将尝试从以下类型进行转换;

对象，Boolean, Char, SByte, Byte, Int16, UInt16, Int32, UInt32, Int64, UInt64，单个，双精度，十进制，字符串，日期

它还有很多其他的方法;一种方法与数字基础有关，两种方法涉及系统。IFormatProvider

另一方面，Parse只有4种重载或者4种调用方法的不同方式。

Integer.Parse( s As String)

Integer.Parse( s As String,  style As System.Globalization.NumberStyles )

Integer.Parse( s As String, provider As System.IFormatProvider )

Integer.Parse( s As String,  style As System.Globalization.NumberStyles, provider As System.IFormatProvider )

转换。ToInt32允许空值，它不会抛出任何错误 Int。解析不允许空值，它会抛出ArgumentNullException错误。

为了澄清打开控制台应用程序，只需复制下面的代码并将其粘贴在静态void Main(string[] args)方法中，希望你能理解

public  class Program
    {
        static void Main(string[] args)
        { 
            int result;
            bool status;
            string s1 = "12345";
            Console.WriteLine("input1:12345");
            string s2 = "1234.45";
            Console.WriteLine("input2:1234.45");
            string s3 = null;
            Console.WriteLine("input3:null");
            string s4 = "1234567899012345677890123456789012345667890";
            Console.WriteLine("input4:1234567899012345677890123456789012345667890");
            string s5 = string.Empty;
            Console.WriteLine("input5:String.Empty");
            Console.WriteLine();
            Console.WriteLine("--------Int.Parse Methods Outputs-------------");
            try
            {
               result = int.Parse(s1);

               Console.WriteLine("OutPut1:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut1:"+ee.Message);
            }
            try
            {
              result = int.Parse(s2);

              Console.WriteLine("OutPut2:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut2:" + ee.Message);
            }
            try
            {
               result = int.Parse(s3);

               Console.WriteLine("OutPut3:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut3:" + ee.Message);
            }
            try
            {
                result = int.Parse(s4);

                Console.WriteLine("OutPut4:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut4:" + ee.Message);
            }

            try
            {
                 result = int.Parse(s5);

                 Console.WriteLine("OutPut5:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut5:" + ee.Message);
            }
            Console.WriteLine();
            Console.WriteLine("--------Convert.To.Int32 Method Outputs-------------");
            try
            {

                result=  Convert.ToInt32(s1);

                Console.WriteLine("OutPut1:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut1:" + ee.Message);
            }
            try
            {

                result = Convert.ToInt32(s2);

                Console.WriteLine("OutPut2:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut2:" + ee.Message);
            }
            try
            {

         result = Convert.ToInt32(s3);

         Console.WriteLine("OutPut3:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut3:" + ee.Message);
            }
            try
            {

                  result = Convert.ToInt32(s4);

                  Console.WriteLine("OutPut4:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut4:" + ee.Message);
            }

            try
            {

                 result = Convert.ToInt32(s5);

                 Console.WriteLine("OutPut5:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut5:" + ee.Message);
            }

            Console.WriteLine();
            Console.WriteLine("--------TryParse Methods Outputs-------------");
            try
            {

                status = int.TryParse(s1, out result);
                Console.WriteLine("OutPut1:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut1:" + ee.Message);
            }
            try
            {

                status = int.TryParse(s2, out result);
                Console.WriteLine("OutPut2:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut2:" + ee.Message);
            }
            try
            {

                status = int.TryParse(s3, out result);
                Console.WriteLine("OutPut3:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut3:" + ee.Message);
            }
            try
            {

                status = int.TryParse(s4, out result);
                Console.WriteLine("OutPut4:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut4:" + ee.Message);
            }

            try
            {

                status = int.TryParse(s5, out result);
                Console.WriteLine("OutPut5:" + result);
            }
            catch (Exception ee)
            {
                Console.WriteLine("OutPut5:" + ee.Message);
            }


            Console.Read();
        }
    }

请看反射镜:

int.Parse("32"):

public static int Parse(string s)
{
    return System.Number.ParseInt32(s, NumberStyles.Integer, NumberFormatInfo.CurrentInfo);
}

这是一个调用:

internal static unsafe int ParseInt32(string s, NumberStyles style, NumberFormatInfo info)
{
    byte* stackBuffer = stackalloc byte[1 * 0x72];
    NumberBuffer number = new NumberBuffer(stackBuffer);
    int num = 0;
    StringToNumber(s, style, ref number, info, false);
    if ((style & NumberStyles.AllowHexSpecifier) != NumberStyles.None)
    {
        if (!HexNumberToInt32(ref number, ref num))
        {
            throw new OverflowException(Environment.GetResourceString("Overflow_Int32"));
        }
        return num;
    }
    if (!NumberToInt32(ref number, ref num))
    {
        throw new OverflowException(Environment.GetResourceString("Overflow_Int32"));
    }
    return num;
}

Convert.ToInt32("32"):

public static int ToInt32(string value)
{
    if (value == null)
    {
        return 0;
    }
    return int.Parse(value, CultureInfo.CurrentCulture);
}

正如第一个(Dave M的)评论所说。

区别在于:

Int32.Parse()和Int32.TryParse()只能转换字符串。Convert.ToInt32()可以接受任何实现IConvertible的类。如果传递给它一个字符串，那么它们是等效的，除了类型比较等额外开销。如果要转换字符串，那么TryParse()可能是更好的选择。