Question

我在调用字符串方法时面临一个非常奇怪的问题。

我有一个视图控制器，我通过蓝牙访问/发送/接收信息＆＃34;默认CoreBlueTooth API＆＃34;

所以最初在页面上加载我的字符串方法和属性，如Characters.count和方法，如替换正在工作。

但是一旦蓝牙扫描程序开始（特别是我读的时候），我的字符串方法就会停止工作，并且相同的行为会转移到所有应用程序。

收到的错误是：

源代码：

          let deadlineTime = DispatchTime.now() + .seconds(4)
          DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute:     {

        let getMacIdHex = "a7".lowercased();
         // String Charactor count works here 
         print("Item test:",self.testString.characters.count);
        self.writeValueChar(data: getMacIdHex) { (callback) in
            print(callback);
            self.logTextView.text = self.logTextView.text + "\n" + "value A7 Get Device UID";
            print("Item test:",self.testString.characters.count);
             //  but String Charactor count doesnt works here ,its in call back
            self.readValueChar { (command, code, xml) in
                //
                 print("Item test:",self.testString.characters.count);
                self.logTextView.text = self.logTextView.text + "\n" + "Mac returned " + command + "\n" + code + "\n" + xml
                print(command, code, xml);

                let macAddress = xml.replacingOccurrences(of: "0000_", with: "")

                //self.lblMacId.text = "MAC address : " + macAddress;
                self.theMacAddress = macAddress;
                completion(true);
                //self.tableView.reloadData();
                //UtilityHelper.HideLoader();

            }


        }
    })
}

错误：执行被中断，原因：EXC_BAD_ACCESS（代码= 1，地址= 0x345f3030303000a7）。

我90％肯定，错误来自ble read功能：

      func readValueChar(completion: @escaping (_ commandNumber: String, _ signalBit: String, _ xmlStr: String) -> Void){
    if(writableCharacteristic != nil){

        peripheral.readValue(for: writableCharacteristic!);
        //print(writableCharacteristic);


        let deadlineTime = DispatchTime.now() + .seconds(2)
       RunbackgroundThread(delay:2, completion:{
        // DispatchQueue.main.asyncAfter(deadline: deadlineTime, execute: {

            self.peripheral.readValue(for: self.writableCharacteristic!);
            //print(self.writableCharacteristic);

            let data = self.writableCharacteristic?.value;
            var byteArray: [UInt8] = [];
            data?.copyBytes(to: &byteArray, count: (data?.count)!);

            let commandNumber = String(format:"%2X", (data?[0])!);
            let signalBit = String(format:"%2X", (data?[1])!);

            var xmlStr:String = ""
            if((data?.count)! >= 2){

                var test2 = data?[2..<(data?.count)!]
                xmlStr = String(bytes: test2!, encoding: String.Encoding.utf8)!
                //print(xmlStr)

            }

            completion(commandNumber, signalBit, xmlStr);

        })





    }
}

任何人都可以解释这种行为以及如何解决它。

由于

字符串方法喜欢＆＃34; characters.count＆＃34;一些访问BLE后无法正常工作

0 个答案: