,NSData 与 NSString
NSData --> NSString
NSString *aString = [[NSString alloc] initWithData:adata encoding:NSUTF8StringEncoding];
NSString --> NSData
NSString *aString = @"";
NSData *aData = [aString dataUsingEncoding: NSUTF8StringEncoding]; ,NSData 与 Byte
NSData --> Byte
NSString *testString = @"";
NSData *testData = [testString dataUsingEncoding: NSUTF8StringEncoding];
Byte *testByte = (Byte *)[testData bytes];
Byte --> NSData
Byte byte[] = {,,,,,,,,,,,,,,,,,,,,,,,};
NSData *adata = [[NSData alloc] initWithBytes:byte length:]; ,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); ,NSData 与 NSMutableData
NSData --> MSMutableData
NSData *data=[[NSData alloc]init];
NSMutableData *mdata=[[NSMutableData alloc]init];
mdata=[NSData dataWithData:data]; ,NSData合并为一个NSMutableData - (NSString *)filePathWithName:(NSString *)filename
{
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDirectory = [paths objectAtIndex:];
return [documentsDirectory stringByAppendingPathComponent:filename];
} - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
//音频文件路径
NSString *mp3Path1 = [[NSBundle mainBundle] pathForResource:@"" ofType:@"mp3"];
NSString *mp3Path2 = [[NSBundle mainBundle] pathForResource:@"" ofType:@"mp3"];
//音频数据
NSData *sound1Data = [[NSData alloc] initWithContentsOfFile: mp3Path1];
NSData *sound2Data = [[NSData alloc] initWithContentsOfFile: mp3Path2];
//合并音频
NSMutableData *sounds = [NSMutableData alloc];
[sounds appendData:sound1Data];
[sounds appendData:sound2Data];
//保存音频 NSLog(@"data length:%d", [sounds length]); [sounds writeToFile:[self filePathWithName:@"tmp.mp3"] atomically:YES]; [window makeKeyAndVisible]; return YES;
}