转换字节数组到UIImage

我有一个字节数组存储在我的Postgres数据库（字段类型bytea）。转换字节数组到UIImage

的API返回它我想：

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

我看到数据库字段包含：

\211PNG\015\012\032\012\000\000\000\015IHDR\000\000\000\301\000\000\000\313\010\006\000\000\000\327\331\367\372\000\000\001|iCCPICC Profile\000\000(\221c``*I,(\310aa``\310\315+)\012rwR\210\210\214R`\277\303\300\315\300\303 \304`\305 \236\230\\\\\340\030\020\340\303\200\023|\273\306\300\010\242/\353\202\314J\363\374y\323\246\265|\376\0266\257\231rV%:\270\365\201\001wJjq2\003\003#\007\220\235\234R\234\234\013d\347\000\331:\311\005E%@\366\014 [\267\274\244\000\304>\001d\213\024\001\035\010d\337\001\261\323!\354\017 v\022\230\315\304\002V\023\022\344\014dK\000\331\002I\020\266\006\210\235\016a[\200\330\311\031\211)@\266\007\310.\210\033\300\200\323\303E\301\334\300R\327\221\200\273I\006\2719\2450;@\241\305\223\232\027\032\014r\007\020\3130x0\2700(0\2303\0300X2\35028\226\244V\224\200\024:\347\027T\026e\246g\224(8\002C6U\3019?\267\240\264$\265HG\3013/YOG\301\310\300\320\000\244\016\024g\020\243?\007\201Mg\024;\217\020\313_\310\300`\251\314\300\300\334\203\020K\232\306\300\260}\017\003\203\304)\204\230\312<\006\006~k\006\206m\347\012\022\213\022\341\016g\374\306B\210_\234fl\004a\363810\260\336\373\377\377\263\032\003\003\373$\006\206\277\023\377\377\377\275\350\377\377\277\213\201\366\003\343\[email protected]\016\000$wi\340\214k\022\017\000\000\001\235iTXtXML:com.adobe.xmp\000\000\000\000\000<x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="XMP Core 5.4.0">\012 <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">\012  <rdf:Description rdf:about=""\012   xmlns:exif="http://ns.adobe.com/exif/1.0/">\012   <exif:PixelXDimension>193</exif:PixelXDimension>\012   <exif:PixelYDimension>203</exif:PixelYDimension>\012  </rdf:Description>\012 </rdf:RDF>\012</x:xmpmeta>\012\321\345>B\000\000\003\344IDATx\001\355\323\001\015\000 \014\[email protected]\343\374[\201\004\033\3279X\363\267g\346.G ,p\302\277{\235\300\027\020\201!\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\[email protected]^@\004\371\011\000\020\201\015\344\005\036\307\307\003\221ASA\204\000\000\000\000IEND\256B`\202

这应该是在字节数组表示的图像。

我想解析这个字节数组回到UIImage使用Swift。对于我有以下功能：

func convertImage(image: String) -> UIImage? { 
    var strings = image.components(separatedBy: ",") 
    var bytes = [UInt8]() 

    for i in 0 ... strings.count-1 { 
     if let signedByte = Int8(strings[i]) { 
      bytes.append(UInt8(bitPattern: signedByte)) 
     } else { 
      print("ERROR") 
      // Do something with this error condition 
     } 
    } 
    let datos: NSData = NSData(bytes: bytes, length: bytes.count) 
    return UIImage(data: datos as Data) // Note it's optional. Don't force unwrap!!! 
}

这似乎是遍历这个功能，但“ERROR”并得到印在最后。然而，我永远不会有UIImage。

我在做什么错？

来源

2017-09-06 Rutger Huijsmans

那些“字节”在** base64编码将其转换为数据**，presummably让你的API可以把它作为文本（不是二进制数据）。你需要将它转换回二进制（Google how），然后你有一个'Data' /'NSData'实例，用它可以初始化一个'UIImage'。 –

iVBORw0KGgoAAAANSUhEUgAAA...代表base64编码字符串。所以，你只需要使用方法

let data = Data(base64Encoded: "iVBORw0KGgoAAAANSUhEUgAAA...") 
let image = UIImage(data: data)

希望它会帮助你

来源

2017-09-06 08:18:10

let o = Int8("-127") 
print(o.dynamicType) // Optional(<Int8>) 
// It's optional, so we need to unwrap it... 
if let x = o { 
print(x) // -127, as expected 
//let b = UInt8(x) // Run time crash 
let b = UInt8(bitPattern: x) // 129, as it should be 
}

因此你的功能应该是

func convierteImagen(cadenaImagen: String) -> UIImage? { 
var strings = cadenaImagen.componentsSeparatedByString(",") 
var bytes = [UInt8]() 
for i in 0..< strings.count { 
    if let signedByte = Int8(strings[i]) { 
     bytes.append(UInt8(bitPattern: signedByte)) 
    } else { 
     // Do something with this error condition 
    } 
} 
let datos: NSData = NSData(bytes: bytes, length: bytes.count) 
return UIImage(data: datos) // Note it's optional. Don't force unwrap!!! 
}

来源

2017-09-06 08:18:06

转换字节数组到UIImage

回答

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