Convert nsdata to nsstring, byte, and uiimage in object-C

1. nsdata and nsstring
Nsdata --> nsstring
Nsstring * astring = [[nsstring alloc] initwithdata: aData encoding: nsutf8stringencoding];
Nsstring --> nsdata
Nsstring * astring = @ "1234 ";
Nsdata * aData = [astring datausingencoding: nsutf8stringencoding];

2. nsdata and byte
Nsdata --> byte
Nsstring * teststring = @ "1234567890 ";
Nsdata * testdata = [teststring datausingencoding: nsutf8stringencoding];
Byte * testbyte = (byte *) [testdata bytes];
Byte --> nsdata
Byte byte [] = {, 21 };
Nsdata * aData = [[nsdata alloc] initwithbytes: Byte Length: 24];

3. nsdata and uiimage
nsdata --> uiimage
uiimage * aimage = [uiimage imagewithdata: imagedata];
// example: obtain the image from the local file sandbox and convert it to 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 and nsmutabledata
Nsdata --> msmutabledata
Nsdata * Data = [[nsdata alloc] init];
Nsmutabledata * mdata = [nsmutabledata alloc] init];
Mdata = [nsdata datawithdata: Data];

5. Merge nsdata into an 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 didfinishlaunchingwitexceptions :( nsdictionary * ) Launchoptions { 9       //  Audio File Path  10 Nsstring * mp3path1 = [[nsbundle mainbundle] pathforresource: @"  1  " Oftype: @"  MP3  "  ];  11 Nsstring * mp3path2 = [[nsbundle mainbundle] pathforresource: @"  2  " Oftype: @"  MP3  "  ];  12           //  Audio Data  13 Nsdata * sound1data = [[Nsdata alloc] initwithcontentsoffile: mp3path1];  14 Nsdata * sound2data = [[Nsdata alloc] initwithcontentsoffile: mp3path2];  15           //  Merge audio 16 Nsmutabledata * Sounds = [Nsmutabledata alloc];  17   [Sounds appenddata: sound1data];  18   [Sounds appenddata: sound2data];  19           //  Save audio  20   21 Nslog ( @"  Data Length: % d  "  , [Sounds length]); 22   23 [Sounds writetofile: [self filepathwithname: @"  Tmp133  "  ] Atomically: Yes];  24           25   [Window makekeyandvisible];  26       27       Return  Yes;  28 }

6. nsstring merge

1 Nsstring * String ; //  Result string  2 Nsstring * string1, string2; //  The existing string. You need to connect string1 and string2.  3   //  Method 1.  4   String = [Nsstring initwithformat: @"  % @, % @  " , String1, string2];  5   //  Method 2.  6   String = [String1 stringbyappendingstring: string2];  7   //  Method 3.  8   String = [ String Stringbyappendingformat: @"  % @, % @ " , String1, string2];