Question

在我们的项目中，当我们捕获图像时，我们将图像存储在本地应用程序路径中，并且采用加密格式。并添加一些信息。最后，我们压缩了所有图像并将其发送到服务器，这是我们当前的流程。

我们想要做的是将图像转换为数据并编码为base64格式。但是如何压缩所有图像（我们需要捕获5个以上的图像）。

压缩所有base64格式的字符串并将其发送到服务器。怎么做？

您是否想将图像保存在内存中并压缩所有这些图像并发送到服务器，而不是将图像存储在应用程序文件夹中？

Answer 1

1-将每个图像转换为数据并编码为base64格式并压缩：

let strBase64 = imageData.base64EncodedString(options: .lineLength64Characters)
print(strBase64)

使用chilkat的压缩字符串：https://www.example-code.com/swift/compress_decompress_string.asp

func chilkatTest() {
//  This example requires the Chilkat API to have been previously unlocked.
//  See Compression UnlockComponent for sample code.

var success: Bool
let sb = CkoStringBuilder()

var i: Int
for i = 1; i <= 20; i++ {
    sb.Append("This is the original uncompressed string.\r\n")
}

let compress = CkoCompression()
compress.Algorithm = "deflate"
//  Indicate that the utf-8 byte representation of the string should be compressed.
compress.Charset = "utf-8"

var compressedBytes: NSData
compressedBytes = compress.CompressString(sb.GetAsString())

//  If the compressed data is desired in string format, then get the base64 representation of the bytes.
compress.EncodingMode = "base64"
var compressedBase64: String? = compress.CompressStringENC(sb.GetAsString())
print("Compressed Bytes as Base64: \(compressedBase64!)")

//  Now decompress...
var decompressedString: String? = compress.DecompressString(compressedBytes)
print("The original string after decompressing from binary compressed data:")
print("\(decompressedString!)")

//  To decompress from Base64...
compress.EncodingMode = "base64"
decompressedString = compress.DecompressStringENC(compressedBase64)
print("The original string after decompressing from Base64:")
print("\(decompressedString!)")

}

2-以json格式保存：

   [
     {"1": "strBase64FromStep1"},
     {"2": "strBase64FromStep1"},
      .
      .
      .
   ]

3-将json字符串保存到文本文件：

let file = "file.txt" //this is the file. we will write to and read from it

let text = "some text" //just a text

if let dir = FileManager.default.urls(for: .documentDirectory, in: 
    .userDomainMask).first {

    let fileURL = dir.appendingPathComponent(file)

    //writing
    do {
        try text.write(to: fileURL, atomically: false, encoding: .utf8)
    }
    catch {/* error handling here */}

    //reading
    do {
        let text2 = try String(contentsOf: fileURL, encoding: .utf8)
    }
    catch {/* error handling here */}
}

4-将文件网址保存到UserDefaults：

fileURL From step 3 

NSUserDefaults.standardUserDefaults().setObject(fileURL, forKey: "path")
NSUserDefaults.standardUserDefaults().synchronize()

5-随时要将其发送到服务器时使用此文件。

如何将图像保存在内存中以及如何快速压缩所有图像？

1 个答案: