#include在查找预编译头文件时跳过——查找预编译头文件时意外结束

我有一些代码，但它不能编译。我不能在这个例子中进一步说明，因为每次我尝试调试时都会出现这个错误。注意:我是Java程序员，这个消息在VS是奇怪的，我找不到什么问题。有人能解释一下这个错误是什么意思吗?

代码如下:

zadatak.cpp:

// zadatak.cpp : Defines the entry point for the console application.
//
#include "stdafx.h"
#include "String.h"
#include <iostream>
using namespace std;
void main()
{
    String s1(20),s2(20);
    cout<<"Unesi prvi string."<<endl;
    cin>>s1;
    cout<<"Unesi drugi string."<<endl;
    cin>>s2;
    ++s1;
    s2++;
    String s3(40);
    s3=s1+s2;
    cout<<"Treci string: "<<s3<<endl;
}

String.cpp:

#include "String.h"
#include <iostream>
using namespace std;
#include <string.h>
String::String(void)
:duzina(0)
{
    niz=new char[duzina];
}
String::String(int br)
:duzina(br)
{
    this->niz=new char[duzina];
}
String::~String(void)
{
    delete [] niz;
}
String::String(String& s)
:duzina(s.duzina)
{
    this->niz=new char[this->duzina];
    for(int i=0; i<this->duzina; i++)
        this->niz[i]=s.niz[i];
}
void String::nadjiPocetak(char rec[])
{
    int poc=0;
    for(int i=0; i<this->duzina; i++)
    {
        int duz=0;
        if(this->niz[i]==rec[0])
        {
            int l=strlen(rec);
            for(int j=0; j<l; j++)
                if(this->niz[i+j]==rec[j])
                    duz+=1;
        }
        if(duz==strlen(rec))
            poc=i;
    }
    if(poc==0)
        cout<<"U stringu ne postoji zadati string."<<endl;
    else
        cout<<"Pocetak je na poziciji: "<<poc+1<<endl;
}
/*void String::ucitaj()
{
    cout<<"Unesi string"<<endl;
    cin>>this->niz;
}
void String::prikazi()
{
    cout<<"String: "<<this->niz<<endl;
}*/
String& String::operator+ (String s)
{
    String *s1;
    s1=new String(duzina+s.duzina);
    strcpy(s1->niz,niz);
    strcat(s1->niz,s.niz);
    return *s1;
}
String& String::operator++ ()
{
    if(niz[0]>='a' && niz[0]<='z')
        niz[0]='A'+niz[0]-'a';
    return *this;
}
String& String::operator++ (int n)
{
    for(int i=0; i<duzina; i++)
        if(niz[i]>='a' && niz[i]<='z')
            niz[i]='A'+niz[i]-'a';
    return *this;
}
String& String::operator= (String& s)
{
    duzina=s.duzina;
    delete [] niz;
    niz=new char[duzina];
    strcpy(niz,s.niz);
    return *this;
}
istream& operator>> (istream& in, String& s)
{
    in>>s.niz;
    return in;
}
ostream& operator<< (ostream& out, String& s)
{
    out<<s.niz;
    return out;
}

String.h:

#pragma once
#include <iostream>
using namespace std;
class String
{
private:
    int duzina;
    char* niz;
public:
    String(void);
    String(int br);
    ~String(void);
    String(String& s);
    int vratiDuzinu() {return this->duzina;}
    void nadjiPocetak(char rec[]);
    //void ucitaj();
    //void prikazi();
    String& operator+ (String s);
    String& operator++ ();
    String& operator++ (int n);
    String& operator= (String& s);
    friend istream& operator>> (istream& in, String& s);
    friend ostream& operator<< (ostream& out, String& s);
};

Visual Studio给出的输出错误是:

1>------ Build started: Project: zadatak, Configuration: Debug Win32------
1>Build started 12/13/2011 02:44:50 AM.
1> InitializeBuildStatus:
1>点击"Debugzadatak.unsuccessfulbuild"。
1> ClCompile:
1>所有输出都是最新的。
1> zadatak.cpp
1> String.cpp
1>c:usersivodocumentsvisual studio 2010projectszadatakzadatakstring.cpp(1):警告C4627: '#include "String.h"':在查找预编译头文件时跳过
1>为'StdAfx.h'添加指令或重新编译头文件
1>c:usersivodocumentsvisual studio 2010projectszadatakzadatakstring.cpp(2):警告C4627: '#include ':在查找预编译头文件时跳过
1>为'StdAfx.h'添加指令或重新编译头文件
1>c:usersivodocumentsvisual studio 2010projectszadatakzadatakstring.cpp(4):警告C4627: '#include ':在查找预编译头文件时跳过
1>为'StdAfx.h'添加指令或重新编译头文件
1>c:usersivodocumentsvisual studio 2010projectszadatakzadatakstring.cpp(108):致命错误C1010:查找预编译头文件时意外结束文件。您是否忘记在源代码中添加"#include"StdAfx.h ?
1>生成代码…
1>
1>构建失败了。
1>
1>时间流逝00:00:00.41
========== 构建:0成功,1失败,最新的,0跳过 ==========