iphone知识汇总2

 iPhone上读取ansi字符串的例子   

 

 

iPhone的NSString并不支持ansi的字符串(比如咱们常用的gb2312), 因此如果要读取的话, 需要转换为UTF-8的

而iPhone上自带了libiconv库, 于是这个转换变的就比较简单了

 

首先在工程的Framework部分加入 /Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS3.0.sdk/usr/lib/libiconv.dylib

当然, 中间那个iPhoneOS3.0.sdk需要换成你当前使用的SDK版本

 

实际转换过程也就4步.

1, 引入iconv库并添加头文件

2, 利用iconv_open设置from和to的字符串编码

3, 执行iconv进行转换

4, 利用iconv_close关闭iconv_open创建的实例.

 

基本上就是下面的代码片段中 code_convert中的逻辑了.

#include <iconv.h>   int code_convert(char *from_charset, char *to_charset, char *inbuf, size_t inlen, char *outbuf, size_t outlen) {     iconv_t cd = NULL;       cd = iconv_open(to_charset, from_charset);     if(!cd)         return -1;       memset(outbuf, 0, outlen);     if(iconv(cd, &inbuf, &inlen, &outbuf, &outlen) == -1)         return -1;       iconv_close(cd);     return 0; }   int u2g(char *inbuf, size_t inlen, char *outbuf, size_t outlen) {     return code_convert("utf-8", "gb2312", inbuf, inlen, outbuf, outlen); }   int g2u(char *inbuf, size_t inlen, char *outbuf,size_t outlen) {     return code_convert("gb2312", "utf-8", inbuf, inlen, outbuf, outlen); }

 

 

而在实际应用时, 无论从文件或者网络读取, 都要获取成NSData或者char *或void *, 至少不能是NSString, 因为NSString无法直接处理.

以获取成NSData为例.

 

+ (NSString *)getANSIString:(NSData *)ansiData {     char *ansiString = [ansiData bytes];     int ansiLen = [ansiData length];     int utf8Len = ansiLen * 2; //其实*1.5基本就够了     char *utf8String = (char *)malloc(utf8Len);     memset(utf8String, 0, utf8Len); //虽然code_convert中也memset了, 但还是自己分配后就set一次比较好     int result = code_convert("gb2312", "utf-8", ansiString, ansiLen, utf8String, utf8Len);     if(result == -1) {         free(utf8String);         return nil;     }     NSString *retString = [NSString stringWithUTF8String:utf8String];     free(utf8String);     return retString; }

代码并未实际跑过, 不过逻辑上应该没有问题 (其实转换部分是抄的)
例子工程嘛, 就算了吧.

自动调整UILabel的高度

UILabel* label = [[UILabel alloc] initWithFrame:CGRectMake(0, 0, 0, 0)]; // 这个大小可以随便写,反正后面会改变他   label.backgroundColor = [UIColor redColor]; label.font = [UIFont systemFontOfSize:40];//这个也随便设, 任何字体都会自动计算出 合适的大小 label.text = @"1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz1234567890abcdefghijklmnopqrstuvwxyz"; //label.text = @"1234";   label.numberOfLines = 0;//这个一定要设成0   CGSize ssize = [label sizeThatFits:CGSizeMake(100, 0)]; /*这个的意思是,我希望我这个label的宽度是100, 而高度随着字符串的长增加 一定要注意, 自适应时, 是以适应width为基准的, 达到这个width后, 就会接着改变height 也就是说, 如果你的字符串很长很长, 那么他会把width固定, 然后得到适合这个字符串的height 所以这里size的height我设成了0, 因为他肯定是要被改变的, 如果你的字符串很短, 达不到那个width, 这时会自动的得到适合这个字符串的width */   CGRect rct = label.frame; rct.size = ssize; label.frame = rct; label.center = CGPointMake(160, 160);

使用NSStreams建立TCP�接 (在iPhone OS不支持NSHost得情�r下)        ��rde地址: ��砜赡��去掉url�e�得prerelease Technical Q&A QA1652Using NSStreams For A TCP Connection Without NSHost   Q: Given that +getStreamsToHost:port:inputStream:outputStream: is not supported on iPhone OS, how can I create NSStreams for a TCP connection to a named host? A: You can do this by exploiting the toll-free bridge between NSStream and CFStream. Use CFStreamCreatePairWithSocketToHost to create CFStreams to the host, and then cast the resulting CFStreams to NSStreams.   Listing 1 shows an example of this. It adds a category to NSStream that implements a replacement for +getStreamsToHost:port:inputStream:outputStream:.   Listing 1: A category to creates TCP streams to a named host       @interface NSStream (MyAdditions)   + (void)getStreamsToHostNamed:(NSString *)hostName      port:(NSInteger)port      inputStream:(NSInputStream **)inputStreamPtr      outputStream:(NSOutputStream **)outputStreamPtr;   @end   @implementation NSStream (MyAdditions)   + (void)getStreamsToHostNamed:(NSString *)hostName      port:(NSInteger)port      inputStream:(NSInputStream **)inputStreamPtr      outputStream:(NSOutputStream **)outputStreamPtr {     CFReadStreamRef     readStream;     CFWriteStreamRef    writeStream;       assert(hostName != nil);     assert( (port > 0) && (port < 65536) );     assert( (inputStreamPtr != NULL) || (outputStreamPtr != NULL) );       readStream = NULL;     writeStream = NULL;       CFStreamCreatePairWithSocketToHost(         NULL,          (CFStringRef) hostName,          port,          ((inputStreamPtr  != nil) ? &readStream : NULL),         ((outputStreamPtr != nil) ? &writeStream : NULL)     );       if (inputStreamPtr != NULL) {         *inputStreamPtr  = [NSMakeCollectable(readStream) autorelease];     }     if (outputStreamPtr != NULL) {         *outputStreamPtr = [NSMakeCollectable(writeStream) autorelease];     } }   @end

iPhone类代码]保存数据：多个对象        存： [[NSArray arrayWithObjects:playername,GameSavedata,nil] writeToFile:self.saveScorefile atomically:NO];     取： NSArray *datapaths = NSSearchPathForDirectoriesInDomains(                                                              NSDocumentDirectory,                                                               NSUserDomainMask,                                                               YES);               self.saveScorefile=[NSString stringWithFormat: @"%@/scoredata.plist", [datapaths objectAtIndex:0]];     if([[NSFileManager defaultManager] fileExistsAtPath:saveScorefile])         self.datascorearray=[NSMutableArray arrayWithContentsOfFile:saveScorefile];             else         self.datascorearray=[ NSMutableArray arrayWithContentsOfFile:[[NSBundle mainBundle]  pathForResource:@"scoredata" ofType:@"plist"]];          self.playername=[self.datascorearray objectAtIndex:0];     self.GameSavedata=[self.datascorearray objectAtIndex:1];

每次点击UITextView输入文本都从头开始的代码        原理很简单 实现一个UITextView的协议 用这个代码可以实现每次开始输入光标都从最初点开始的效果       - (void)textViewDidChangeSelection:(UITextView *)textView {     NSRange range;     range.location = 0;     range.length  = 0;     textView.selectedRange = range; }

Matrix Digital Raining �赢�效果        用cocos2d 作成的 Matrix Digital Raining �赢�效果  .h �n     #define GRADIENT     10 #define SCREENWIDTH  480 #define SCREENHEIGHT 360 #define FONTSIZE     10 #define FONTSPACE    1 #define CHARROW      (SCREENHEIGHT / FONTSIZE) #define CHARCOLUMN   (SCREENWIDTH / FONTSIZE)     @interface background : CCLayer {             CCTimer *timer;             NSString *msg;             int length;             ccColor3B colorList[GRADIENT];             CCBitmapFontAtlas *fontArray[CHARCOLUMN][CHARROW];             int drop[CHARROW]; }   @end       .m �n     @implementation background - (id)init {         self = [super init];         if (self != nil)         {                 msg = @"abcdefghijklmnopqestuvwxyzABCDEFGHJIKLMNOPQRSTUVWXYZ1234567890";                   length = [msg length];                 colorList[0] = ccc3(0, 0, 0);                 // Initial the color gradient                 for (int i = 1; i < GRADIENT; ++i)                         colorList[i] = ccc3(0, 255-20*i, 0);                   for (int i = 0; i < CHARCOLUMN; ++i)                 {                         for (int j = 0; j < CHARROW; ++j)                         {                                 fontArray[i][j] = [CCBitmapFontAtlas bitmapFontAtlasWithString:[msg substringWithRange:NSMakeRange(rand()%length, 1)] fntFile:@"matrixFont.fnt"];                                 fontArray[i][j].position = *****(SCREENWIDTH - i * FONTSIZE, SCREENHEIGHT- j * FONTSIZE);                                 fontArray[i][j].color = colorList[0];                                 [self addChild:fontArray[i][j]];                         }                         drop[i] = (rand() % CHARCOLUMN);                 }         }         return self; }     - (void) onEnter {         [super onEnter];         timer = [CCTimer timerWithTarget:self selector:@selector(updateBackgroundAnimation:) interval:.1];         [[CCScheduler sharedScheduler] scheduleTimer:timer]; }   - (void) onExit {         [[CCScheduler sharedScheduler] unscheduleTimer:timer];         [super onExit]; }   - (void) updateBackgroundAnimation:(id) sender {         for (int x = 0; x < CHARCOLUMN; ++x)         {                 for (int y = 0; y < drop[x]; ++y)                 {                         if (drop[x] - y <= GRADIENT)                         {                                 fontArray[x][y%CHARROW].color = colorList[drop[x]-y-1];                         }                         else                                 fontArray[x][y%CHARROW].color = colorList[0];                 }                 if (drop[x] < (CHARROW + GRADIENT))                         drop[x]++;                 else                         drop[x] = 0;         } }   @end

自己写的 char* 加入到TextView的method        大家可能用得到吧.... AAA.h: IBOutlet NSTextView * mytextview;     AAA.m   -(void)TextViewProcess:(char *)Text TextColor:(NSColor *)Color //color don't work now { NSString *TextString; NSRange range;   //NSLog(@"%s",Text); TextString=[NSString stringWithFormat:@"%s",Text];  [[[mytextview textStorage] mutableString] appendString:TextString];// add text    range = NSMakeRange([[[Showinfo textStorage] mutableString]length],0);  [mytextview scrollRangeToVisible:range]; //move to end of textview }