致命错误：在解包可选值时意外发现nil

以下是我写的最终代码

//
//  ViewController.swift
//  ImageManipulationWithSwift
//
//  Created by Salman Ali on 01/03/2017.
//  Copyright © 2017 Antzion. All rights reserved.
//

import UIKit
import CoreImage


class ViewController: UIViewController, UIPickerViewDataSource, UIPickerViewDelegate {

var pickerFilters: [String] = [String]()
let path = Bundle.main.path(forResource: "scientist", ofType: "jpg")!

@IBOutlet weak var filterPicker: UIPickerView!
@IBOutlet weak var imageView: UIImageView!

override func viewDidLoad() {

    super.viewDidLoad()
    let categFilters = CIFilter.filterNames(inCategory: kCICategoryColorEffect)

    //pickerFilters.append("CISepiaTone")
    for f in categFilters{
        pickerFilters.append(f)
    }
    filterPicker.dataSource = self
    filterPicker.delegate = self
    applyFilter(index: 0)

}

override func didReceiveMemoryWarning() {
    super.didReceiveMemoryWarning()

}

func applyFilter(index: Int){
    let context = CIContext()
    // 1
    //below two lines will refer the code to GPU instead of cpu
    //let openGLContext = EAGLContext(api: .openGLES2)
    //let context = CIContext(eaglContext: openGLContext!)
    let filter = CIFilter(name: pickerFilters[index])!
    // 2

    //filter.setValue(0.8, forKey: kCIInputIntensityKey)
    let image = CIImage(contentsOf: URL(fileURLWithPath: path))                          // 3
    filter.setValue(image, forKey: kCIInputImageKey)
    let result = filter.outputImage!                                    // 4
    let cgImage = context.createCGImage(result, from: result.extent)    // 5
    //load this image to imageview
    imageView.image = UIImage(cgImage: cgImage!)
}

func numberOfComponents(in pickerView: UIPickerView) -> Int {
    return 1
}

func pickerView(_ pickerView: UIPickerView, numberOfRowsInComponent component: Int) -> Int {
    return pickerFilters.count
}

func pickerView(_ pickerView: UIPickerView, titleForRow row: Int, forComponent component: Int) -> String? {
    self.applyFilter(index: row)
    return pickerFilters[row]
}

func pickerView(_ pickerView: UIPickerView, didSelectRow row: Int, inComponent component: Int) {

}


}

只使用一个过滤器时效果很好。但是当我想向用户显示一个列表然后希望他选择他喜欢的过滤器时，它会崩溃。请帮帮我，我该怎么办？

Answer 1

问题在于您的代理实施：

public class GlobalServer{
GlobalServer(){new Thread(() ->{
    try {
        serverSocket = new ServerSocket(1234);
        Socket clientSocket;
        while (true) {
            clientSocket = serverSocket.accept();
            handleClient(clientSocket);
        }
    } catch (IOException | ClassNotFoundException e) {
        e.printStackTrace();
    }
}).start();
}

public void handleClient(Socket clientSocket) throws IOException, ClassNotFoundException{
    ObjectInputStream is = new ObjectInputStream(clientSocket.getInputStream());
    Object [] objArr = (Object[]) is.readObject();
    msgHandler(objArr, clientSocket);
}

public void msgHandler(Object [] objArr, Socket clientSocket){
    int msg_type = (int) objArr[0];
    switch (msg_type) {
    case 1:
        System.out.println("type 1 received");
        break;
    case 2:
        System.out.println("type 2 received");
        break;
    case 3:
        System.out.println("type 3 received");
        break;

    default:
        break;
    }
}
public static void main(String [] args){
    GlobalServer s = new GlobalServer();
}
}

调用此方法以获取选择器中每个选项的标题。为要显示的选择器视图中的每个项调用它。您似乎正在尝试同时将过滤器应用于图像。我不认为这是你想做的事。

添加过滤器到图像Swift

致命错误：在解包可选值时意外发现nil

1 个答案: