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  • ObjectC 中各数据类型转换 NSData转NSString,Byte,UIImage

    1,NSData 与 NSString
      
    NSData --> NSString
      
    NSString *aString = [[NSString alloc] initWithData:adata encoding:NSUTF8StringEncoding];
      NSString --> NSData
      
    NSString *aString = @"1234";
      NSData *aData = [aString dataUsingEncoding: NSUTF8StringEncoding];

    2,NSData 与 Byte
      
    NSData --> Byte
      
    NSString *testString = @"1234567890";
      NSData *testData = [testString dataUsingEncoding: NSUTF8StringEncoding];
      Byte *testByte = (Byte *)[testData bytes];
      Byte --> NSData
      Byte byte[] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23};
      NSData *adata = [[NSData alloc] initWithBytes:byte length:24];

    3,NSData 与 UIImage
      
    NSData --> UIImage
      
    UIImage *aimage = [UIImage imageWithData: imageData];
      //例:从本地文件沙盒中取图片并转换为NSData
      NSString *path = [[NSBundle mainBundle] bundlePath];
      NSString *name = [NSString stringWithFormat:@"ceshi.png"];
      NSString *finalPath = [path stringByAppendingPathComponent:name];
      NSData *imageData = [NSData dataWithContentsOfFile: finalPath];
      UIImage *aimage = [UIImage imageWithData: imageData];
      UIImage-> NSData
      NSData *imageData = UIImagePNGRepresentation(aimae);

    4,NSData 与 NSMutableData
      NSData --> MSMutableData
      NSData *data=[[NSData alloc]init];
      NSMutableData *mdata=[[NSMutableData alloc]init];  
      mdata=[NSData dataWithData:data];

    5,NSData合并为一个NSMutableData

     1 - (NSString *)filePathWithName:(NSString *)filename
     2 {
     3         NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
     4         NSString *documentsDirectory = [paths objectAtIndex:0];
     5         return [documentsDirectory stringByAppendingPathComponent:filename];
     6 }
     7 
     8 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {    
     9     //音频文件路径
    10         NSString *mp3Path1 = [[NSBundle mainBundle] pathForResource:@"1" ofType:@"mp3"];
    11         NSString *mp3Path2 = [[NSBundle mainBundle] pathForResource:@"2" ofType:@"mp3"];
    12         //音频数据
    13         NSData *sound1Data = [[NSData alloc] initWithContentsOfFile: mp3Path1];
    14         NSData *sound2Data = [[NSData alloc] initWithContentsOfFile: mp3Path2];
    15         //合并音频
    16         NSMutableData *sounds = [NSMutableData alloc];
    17         [sounds appendData:sound1Data];
    18         [sounds appendData:sound2Data];
    19         //保存音频
    20 
    21         NSLog(@"data length:%d", [sounds length]);
    22 
    23         [sounds writeToFile:[self filePathWithName:@"tmp.mp3"] atomically:YES];
    24         
    25         [window makeKeyAndVisible];
    26     
    27     return YES;
    28 }

     6,NSString 合并

    1 NSString* string; // 结果字符串
    2 NSString* string1, string2; //已存在的字符串,需要将string1和string2连接起来
    3 //方法1. 
    4 string = [NSString initWithFormat:@"%@,%@", string1, string2 ];
    5 //方法2. 
    6 string = [string1 stringByAppendingString:string2];
    7 //方法3 . 
    8 string = [string stringByAppendingFormat:@"%@,%@",string1, string2];


      

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  • 原文地址:https://www.cnblogs.com/cpcpc/p/2550230.html
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