Question

我的Postgres数据库中存储了一个字节数组（字段类型为bytea）。

API将它归还给我：

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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 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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\0041@\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\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005D\220\237\000\000\021\330@^@\004\371\011\000\020\201\015\344\005\036\307\307\003\221ASA\204\000\000\000\000IEND\256B`\202

那应该是以字节数组表示的图像。

我想使用Swift将这个字节数组解析回UIImage。为此，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!!!
}

似乎是在循环这个功能但是＆＃34; ERROR＆＃34;最后打印出来。然而，我从未结束过UIImage。

我做错了什么？

Answer 1

iVBORw0KGgoAAAANSUhEUgAAA...代表base64编码的字符串。所以你只需要使用方法

将其转换为数据

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

希望它能帮到你

Answer 2

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!!! 
}

将字节数组转换为UIImage

2 个答案: