[英]Encoding base64 string to image in swift received from mysql
我从mysql接收到base64字符串(存储为blob),并尝试将其编码为:
func loadImage() {
var request = URLRequest(url: URL(string: URL_IMAGES)!)
request.httpMethod = "POST"
let userid = self.defaultValues.integer(forKey: "userid")
let postString = "userid=\(userid)"
request.httpBody = postString.data(using: .utf8)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print("error=\(String(describing: error))")
return
}
if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
print("statusCode should be 200, but is \(httpStatus.statusCode)")
print("response = \(String(describing: response))")
}
let responseString = String(data: data, encoding: .utf8)
if let encodedImage = responseString,
let imageData = NSData(base64Encoded: encodedImage, options: .ignoreUnknownCharacters),
let image = UIImage(data: imageData as Data) {
print(image.size)
}
}
task.resume()
}
php文件如下所示:
<?php
$userid=$_POST["userid"];
$conn = mysqli_connect(connection);
if ($conn->connect_error) {
die("Connection failed: " . $conn>connect_error);
}
$sql = "SELECT profilepicture FROM users WHERE id = $userid";
$result = $conn->query($sql);
if ($result->num_rows > 0) {
while($row = $result->fetch_assoc()) {
$out[]=$row;
}
echo json_encode($out);
} else {
echo "0 results";
}
?>
编辑2 *这就是我将图像存储到数据库中的方式:
@objc func updateUser(sender: UIButton!) {
let refreshAlert = UIAlertController(title: "Update profile?", message: "Do you want to update your profile? This will log you out to update the data!", preferredStyle: UIAlertControllerStyle.alert)
refreshAlert.view.tintColor = UIColor.red
refreshAlert.addAction(UIAlertAction(title: "Ok", style: .default, handler: { (action: UIAlertAction!) in
let URL_REQUEST = "request"
self.messageLbl.text = ""
var request = URLRequest(url: URL(string: URL_REQUEST)!)
request.httpMethod = "POST"
let userid = self.defaultValues.integer(forKey: "userid")
let password = self.passWordTf.text!
let email = self.eMailTf.text!
let image = self.imageView.image!
guard let pictStr = self.convertImageBase64(image: image) else {
return
}
let postString = "id=\(userid)&password=\(password)&email=\(email)&profilepicture=\(pictStr)"
request.httpBody = postString.data(using: .utf8)
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print("error=\(String(describing: error))")
return
}
if let httpStatus = response as? HTTPURLResponse, httpStatus.statusCode != 200 {
print("statusCode should be 200, but is \(httpStatus.statusCode)")
print("response = \(String(describing: response))")
}
let responseString = String(data: data, encoding: .utf8)
print("responseString = \(String(describing: responseString))")
}
task.resume()
if (self.eMailTf.text != self.defaultValues.string(forKey: "useremail")) {
self.defaultValues.set(self.eMailTf.text, forKey: "useremail")
}
self.navigationController?.popViewController(animated: true)
}))
refreshAlert.addAction(UIAlertAction(title: "Cancel", style: .default, handler: { (action: UIAlertAction!) in
print("Handle Cancel Logic here")
}))
present(refreshAlert, animated: true, completion: nil)
}
编辑2 *这是编码功能:
func convertImageBase64(image: UIImage) -> String? {
guard let pictData = UIImagePNGRepresentation(image) else {
return nil
}
let strBase64: String = pictData.base64EncodedString(options: [])
return strBase64
}
编辑2 *和用于存储的php文件:
<?php
$userid=$_POST["userid"];
$password=$_POST["password"];
$pass = md5($password);
$email=$_POST["email"];
$profilepicture=$_POST["profilepicture"];
$conn = mysqli_connect(connection);
if ($conn->connect_error) {
die("Connection failed: " . $conn->connect_error);
}
$sql =("UPDATE users SET password='".$pass."' , email='".$email."' , profilepicture='".$profilepicture."' WHERE id=".$userid."");
if ($conn->query($sql) === TRUE) {
echo "Record updated successfully";
} else {
echo "Error updating record: " . $conn->error;
}
$conn->close();
?>
这是一个类似的问题这个 ,但即使尝试所有的答案并没有为我工作。 我得到的响应是正确的,但我无法对其进行编码,因为我总是在尝试编码时得到nil:
我也尝试过很多类似的事情:
编辑1
im接收的字符串具有以下前缀:“ [{\\” profilepicture \\“:\\” iVBORw0KGgoAAAANSUhE ...
是否可以在没有此前缀的情况下转换字符串,或者该前缀甚至与转换字符串都不相关?
编辑2
您的服务器端代码返回JSON数据,其中包含通过fetch_assoc()
检索的assoc数组的数组。
我建议您更新服务器端代码,因为它返回除图像数据以外的其他内容,因此最好只发送图像数据。
但是,如果您想按原样使用服务器端代码,则可能需要在loadImage
编写如下loadImage
:
let task = URLSession.shared.dataTask(with: request) { data, response, error in
guard let data = data, error == nil else {
print("error=\(error?.localizedDescription ?? "nil")")
return
}
guard let httpResponse = response as? HTTPURLResponse else {
print("response is not an HTTPURLResponse")
return
}
guard httpResponse.statusCode == 200 else {
print("statusCode should be 200, but is \(httpResponse.statusCode)")
print("response = \(httpResponse)")
return
}
do {
//First decode the response body as JSON
let json = try JSONSerialization.jsonObject(with: data)
//The decoded object should be a JSON array containing one JSON object
guard let arr = json as? [[String: Any]], !arr.isEmpty else {
print("json is not an array, or is empty")
return
}
//Use only the first record
let person = arr[0]
//Retrieve the column value of "profilepicture" in the first record
guard let encodedImage = person["profilepicture"] as? String else {
print("NO profilepicture")
return
}
//Decode it into binary data as Base64
guard let imageData = Data(base64Encoded: encodedImage, options: .ignoreUnknownCharacters) else {
print("encodedImage is not a valid Base64")
return
}
//Convert the decoded binary data into an image
guard let image = UIImage(data: imageData) else {
print("imageData is in a unsupported format or is not an image")
return
}
print(image.size)
//Use `image` here...
} catch {
print(error)
}
}
task.resume()
您可能需要修改某些部分,但是当我在坏情况下嵌入许多print
,可以轻松找到要修复的地方。
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