小编Jer*_*myP的帖子

我在我的progrram中有以下代码.我试图将每个数字追加到NSString.我在第二次附加字符串后收到错误.错误是消息发送到解除分配的对象.我知道这是一个内存管理问题.我没有发布小计.有人知道小计被解除分配的原因吗？提前致谢.

-(IBAction)digitPressed:(UIButton *)sender
{
       NSString *digit = [[sender titleLabel] text];
       subtotal=[subtotal stringByAppendingString:digit];
       NSLog(@"appended string is :%@",subtotal);
}

-(void)ViewDidLoad
{
  subtotal = [[NSString alloc]init];

}

全部,需要一些帮助.我来自纯粹的Java背景,对C编程知之甚少.基本上我需要编写一个C程序(并创建一个可执行文件),它将在Windows机器上输出自由字节数(RAM)(XP/2008/7)

我对它做了一些研究,发现有一个名为GlobalMemoryStatusEx的函数,还有一个链接:http://msdn.microsoft.com/en-us/library/aa366589(v = vs.85) .aspx

我用gcc安装了cygwin,上面的程序甚至都没有为我编译.我知道我在做一些愚蠢的事情..

$ gcc hello.c -o hello.exe
hello.c:3:19: error: tchar.h: No such file or directory
hello.c: In function `main':
hello.c:7: error: `MEMORYSTATUSEX' undeclared (first use in this function)
hello.c:7: error: (Each undeclared identifier is reported only once
hello.c:7: error: for each function it appears in.)
hello.c:7: error: expected `;' before `statex'
hello.c:9: error: `statex' undeclared (first use in this function)

很感谢任何形式的帮助!

#include<stdio.h>  
#include<conio.h>  
#define SQUARE(x) (x*x)  
void main()  
{  
    clrscr();  
    int i=3,j,k;  
    j=SQUARE(i++);  
    k=SQUARE(++i);  
    printf("\n%d\n%d\n%d",j,k,i);  
    getch();  
}  

答案令人困惑:9 49 7我在想j = 3*4 = 12,k = 6*7 = 42,i = 7发生了什么事？我错过了什么吗？(x*x)=((x)*(x))这里相同.没关系.

我无法理解指针概念,下面是代码.为什么交换(&a1,&a2)输出-5,6而不是6,-5？这些值已经交换了吗？

void swap(int *ptr1, int *ptr2){

     int temp;

      temp = *ptr1;
      *ptr1 = *ptr2;
      *ptr2 = temp;

}

int main (int argc, char *argv[]){

    void swap(int *ptr1, int *ptr2);
    int a1 = -5;
    int a2 = 6;
    int *p1 = &a1;
    int *p2 = &a2;

    NSLog(@" a1 = %i, a2 =%i", a1, a2); // out puts: -5, 6

    swap(p1,p2);
    NSLog(@" a1 = %i, a2 =%i", a1, a2); // out puts: 6, -5

    swap(&a1, &a2);
    NSLog(@" a1 = %i, a2 =%i", …

当我试图在xcode中运行javascript时,我发现了一些警告,

以下是警告,

[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/binofo.js' of type sourcecode.javascript for architecture i386
[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/excanvas.js' of type sourcecode.javascript for architecture i386
[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/jqtouch.js' of type sourcecode.javascript for architecture i386
[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/jqtouch.min.js' of type sourcecode.javascript for architecture i386
[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/jqtouch.transitions.js' of type sourcecode.javascript for architecture i386
[WARN]warning: no rule to process file '$(PROJECT_DIR)/js/jquery-1.4.4.min.js' of type sourcecode.javascript for architecture i386 …

我是用C++编写程序的新手,我想知道是否有办法将它导出为Windows格式.学习objective-c的好方法是什么,它与c ++有很大的不同吗？先感谢您.

我在以下目标c代码中遇到内存泄漏问题.的粗体带星号(***)线与内存泄漏(在仪器提到的)的行.有什么想法吗？谢谢.

- (UIImage*)part:(float)part ofImage:(UIImage*)imgObject withMask:(UIImage*)imgMask {
 UIImage *imgResult = nil;
 CGRect rcMask = CGRectMake(0.0f, 0.0f, imgMask.size.width, imgMask.size.height);
 CGRect rcObject = CGRectMake(0.5f * (rcMask.size.width - imgObject.size.width), 0.0f, imgObject.size.width, imgObject.size.height * part);

 BytePtr pictureData = (BytePtr)malloc(rcMask.size.width * rcMask.size.height * 4);
 CGContextRef pictureContext = CGBitmapContextCreate(pictureData, rcMask.size.width,              rcMask.size.height,8, rcMask.size.width * 4,CGImageGetColorSpace(imgObject.CGImage),              kCGImageAlphaPremultipliedLast | kCGBitmapByteOrder32Big);

 CGContextClipToMask(pictureContext, rcMask, imgMask.CGImage);
 CGImageRef imgInRect;
 imgInRect = CGImageCreateWithImageInRect(imgObject.CGImage, rcObject);
 CGContextDrawImage(pictureContext, rcObject, imgInRect);
 CGImageRelease(imgInRect);
 ***imgResult = [UIImage imageWithCGImage:CGBitmapContextCreateImage(pictureContext)];***

 CGContextRelease(pictureContext);
 free(pictureData);
 return imgResult;
}

只是 - 我是一个新手,我不知道在任何情况下使用哪一个.

您好我正在编写一个简单的c程序来测试解析c中的缓冲区但是当我运行该程序时,我得到以下错误:

./test.c: line 4: syntax error near unexpected token `('
./test.c: line 4: `int main()'

有谁知道为什么会发生这些错误？谢谢

#include <stdio.h>
#include <stdlib.h>

int main()
{

    char* command;

    char* buf = malloc(100 *sizeof(char));

    buf = "GET /index.html HTTP/1.1\n Host: www.gla.ac.uk\n";

    command  = strtok(buf, " ");
    printf("%s", command );

    free(buf);
}