日志生成；

随机字符串生成

BFCommonKit/Classes/BFUtility/PQCommonMethodUtil.swift

@@ -49,6 +49,13 @@ public let exportVideosDirectory = resourceDirectory + "/ExportVideos/"
 public let versionCode = "\(Bundle.main.infoDictionary?["CFBundleVersion"] ?? "1")"
 // 版本号
 public let versionName = "\(Bundle.main.infoDictionary?["CFBundleShortVersionString"] ?? "1.0.0")"
+
+public let appRunIdentify : String = {
+    let dateFmt = DateFormatter()
+    dateFmt.dateFormat = "MMddHHmmss"
+    return dateFmt.string(from: Date())
+}()
+
 /// 创建目录文件
 /// - Returns: <#description#>
 public func createDirectory(path: String) {
@@ -148,6 +155,13 @@ public func BFLog<T>(_ type: Int = 0, _ file: String = #file, _ line: Int = #lin
     #endif
 }
 
+func writeIntoFile() {
+    if let documentDirectoryPath = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true).first {
+        let filePath = documentDirectoryPath + "/\(appRunIdentify)" + "_logfile.txt"
+        freopen(filePath.cString(using: .ascii), "a", stderr)
+    }
+}
+
 // MARK: 获取公共参数
 
 public func commonParams() -> [String: Any] {
@@ -962,3 +976,23 @@ public func synced(_ lock: Any, closure: () -> Void) {
     closure()
     objc_sync_exit(lock)
 }
+
+/**
+ 生成随机字符串,
+ 
+ - parameter length: 生成的字符串的长度
+ 
+ - returns: 随机生成的字符串
+ */
+public func getRandomStringOfLength(length: Int) -> String {
+    let characters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ"
+
+    var ranStr = ""
+    for _ in 0..<length {
+        let index = Int(arc4random_uniform(UInt32(characters.count)))
+        ranStr.append(characters[index])
+    }
+    return ranStr
+    
+}
+