base64

问题 what I want is to convert RSA Sec key into base64 encoded string with swift. so I initialized a variable like below, var publicKeyBits = Unmanaged<AnyObject>?() then it gives cannot invoke initializer for Unmanaged? with no arguments in swift I want to covert my publickey like below var publicKeyBits = Unmanaged<AnyObject>?() SecItemCopyMatching(queryAttrs, &publicKeyBits) let opaqueBits = publicKeyBits?.toOpaque() let publicKeyData = Unmanaged<NSData>.fromOpaque(opaqueBits)

问题 I got a Json, which contains among others a data field which stores a base64 encoded string. This Json is serialized and send to a client. On client side, the newtonsoft json.net deserializer is used to get back the Json. However, if the data field becomes large (~ 400 MB), the deserializer will throw an out of memory exception: Array Dimensions exceeded supported Range . I also see in Task-Manager, that memory consumption really grows fast. Any ideas why this is? Is there a maximum size for

问题 I have two following classes: public class User { private String name; private Secret secret; public User( @JsonProperty("name") String name, @JsonProperty("secret") Secret secret ) { this.name = name; this.secret = secret; } public String getName() { return name; } public Secret getSecret() { return secret; } } and public class Secret { private byte[] secret; public Secret( byte[] secret ) { this.secret = secret; } @JsonValue public byte[] getSecret() { return secret; } } I would like to use

问题 I have an service which returns the base64 version of an image. Now i want to use the base64 string in the src tag of an img . The service offers the base64 version under http://localhost:8080/file/301/base64 . The base64 string looks like this: data:image/gif;base64,iVBORw0KGgo ... My img tag on the page currently looks like this: <img alt="" src="http://localhost:8080/file/301/base64" style="height:836px; width:592px"> Is there any way to get this running? 回答1: It is not working because you

问题 I have an service which returns the base64 version of an image. Now i want to use the base64 string in the src tag of an img . The service offers the base64 version under http://localhost:8080/file/301/base64 . The base64 string looks like this: data:image/gif;base64,iVBORw0KGgo ... My img tag on the page currently looks like this: <img alt="" src="http://localhost:8080/file/301/base64" style="height:836px; width:592px"> Is there any way to get this running? 回答1: It is not working because you

问题 When I return encrypted or decrypted string in Base64 format it can t resolve BASE64Encoder() and BASE64Dencoder()`. How can I resolve it? import javax.crypto.*; import java.io.*; import java.security.InvalidKeyException; import java.security.NoSuchAlgorithmException; class DesEncrypter { Cipher ecipher; Cipher dcipher; public DesEncrypter(SecretKey key) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException { ecipher = Cipher.getInstance("DES"); dcipher = Cipher

问题 I'm looking to pass a chart export to a component that specifically requires PNG or JPG- so an SVG will unfortunately not work. With the help of other SO answers- I was able to get the SVG Base64 using the following code: let link = "data:image/svg+xml;base64," + btoa(this.lineChartRef.current.CHART.current.chart.getSVG()); Is there a way I can get the PNG base64? Or is there an efficient way within React to convert this SVG base64 to a PNG? Thanks!!! 回答1: Thanks to @ppotaczek for his

问题 I can attach a png image from disc by and everything works just fine: obj.attachment.attach( io: File.open('dog.png'), filename: "image_name", content_type: "image/png" ) But it doesn't work giving result like too tiny empty square when I save a Base64 png image which encoded into String something like that "data:image/png;base64,iVB**..REST OF DATA..**kSuQmCC" by: obj.attachment.attach( io: StringIO.new(encoded_base_sixty_four_img), filename: "image_name", content_type: "image/png" ) Also I

问题 I am looking at an example in dotnet which looks like the following: https://dotnetfiddle.net/t0y8yD. The output for the HttpServerUtility.UrlTokenEncode method is: Pn55YBwEH2S2BEM5qlNrq-LMNE8BDdHYwbWKFEHiPZo1 When I try to complete the same in NodeJS with encodeURI , encodeURIComponent or any other attempt I get the following: Pn55YBwEH2S2BEM5qlNrq+LMNE8BDdHYwbWKFEHiPZo= As you can see from the above the '-' should be a '+' and the last character part is different. The hash is created the

问题 Is there a good way to check if a string is encoded in base64 using Python? 回答1: This isn't possible. The best you could do would be to verify that a string might be valid Base 64, although many strings consisting of only ASCII text can be decoded as if they were Base 64. 回答2: import base64 import binascii try: base64.decodestring("foo") except binascii.Error: print "no correct base64" 回答3: I was looking for a solution to the same problem, then a very simple one just struck me in the head.