android - 在 android studio 中协助处理 MAIN 中的致命异常

Question

我是 Android 编程新手，正在尝试运行该程序，但问题是应用程序构建并成功运行，但每当我按下 GO 按钮时就会崩溃。我的教授让我完成这个任务，作为 Android 编程的开始，因为他认为这将是一项具有挑战性的任务，会充满激励性和有趣。我到处寻找解决方案，但找不到。我的教授本人无法调试代码，因此。

代码如下:

**CODE 1**  

package com.example.thispc.myapplication;
import android.annotation.SuppressLint;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.TextView;
import android.widget.EditText;

import java.util.Scanner;

import edu.princeton.cs.algs4.EdgeWeightedDigraph;
import edu.princeton.cs.algs4.DirectedEdge;
import edu.princeton.cs.algs4.BellmanFordSP;

public class Arbitrage extends AppCompatActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {

    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_arbitrage);

    Button Check_Arbitrage = findViewById(R.id.Check_Arbitrage);
    Check_Arbitrage.setOnClickListener(new View.OnClickListener() {
        @SuppressLint("SetTextI18n")
        @Override
        public void onClick(View view) {

            EditText inputcurrencynumber;
            EditText inputdata;
            TextView outputarbitrage;
            inputcurrencynumber = findViewById(R.id.GetNoCurrencies);
            inputdata = findViewById(R.id.currency_table_input);
            outputarbitrage = findViewById(R.id.result);

            inputcurrencynumber = findViewById(R.id.GetNoCurrencies);
            int V;
            V = Integer.parseInt(inputcurrencynumber.getText().toString());
            outputarbitrage = findViewById(R.id.result);



            double rate,stake;

            inputdata = findViewById(R.id.currency_table_input);

            EdgeWeightedDigraph G = new EdgeWeightedDigraph(V);
            outputarbitrage.setText("Hello World");

            String [] name = new String[V];
            // The error occures here when i try to take an input
            for (int v = 0; v < V ; v++)
            {`enter code here`
                name[v] = inputdata.getText().toString();
                for (int w = 0; w < V ; w++)
                {
                    rate = Double.parseDouble(inputdata.getText().toString());
                    DirectedEdge e = new DirectedEdge(v, w, -Math.log(rate));
                    G.addEdge(e);

                }
           }

            BellmanFordSP spt = new BellmanFordSP(G,0);


            if (spt.hasNegativeCycle())
            {
                stake = 1000;
                for (DirectedEdge e : spt.negativeCycle())
                {
                    //outputarbitrage.setText((Double.toString(stake) + name[e.from()]) + "  " + (Double.toString(stake) + name[e.to()]) + "\n");


                    outputarbitrage.setText("%10.5f %s " + stake + name[e.from()]);
                    stake = stake * Math.exp(-e.weight());
                    outputarbitrage.setText("= %10.5f %s\n" + stake + name[e.to()]);
                }
            }

            else
            {
                outputarbitrage.setText("No Arbitrage Opportunity Found");
            }
        }
    });

}
}

注意:此代码在 java IDE 中完美运行(我使用 netbeans)，但在 android studio 中崩溃。

================================================== =================================================== =================================================== ===编辑1

添加了如下日志:

com.example.thispc.myapplication E/AndroidRuntime: FATAL EXCEPTION: main
                                                                            Process: com.example.thispc.myapplication, PID: 4876
                                                                            java.lang.NumberFormatException: For input string: "USD 1 1.6 4
                                                                            CAD 2.3 1 1.3
                                                                            CHF 4 8 1"
                                                                                at sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:2043)
                                                                                at sun.misc.FloatingDecimal.parseDouble(FloatingDecimal.java:110)
                                                                                at java.lang.Double.parseDouble(Double.java:539)
                                                                                at com.example.thispc.myapplication.Arbitrage$1.onClick(Arbitrage.java:57)
                                                                                at android.view.View.performClick(View.java:6294)
                                                                                at android.view.View$PerformClick.run(View.java:24770)
                                                                                at android.os.Handler.handleCallback(Handler.java:790)
                                                                                at android.os.Handler.dispatchMessage(Handler.java:99)
                                                                                at android.os.Looper.loop(Looper.java:164)
                                                                                at android.app.ActivityThread.main(ActivityThread.java:6494)
                                                                                at java.lang.reflect.Method.invoke(Native Method)
                                                                                at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:438)
                                                                                at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:807)

================================================== =================================================== =================================================== ===编辑2

output

Answer 1

由于以下行而导致崩溃

rate = Double.parseDouble(inputdata.getText().toString());

您正在尝试解析字符串，并且 parseDoubel() 需要仅包含数字值的字符串值，但在您的情况下 inputdata.getText().toString() 包含数字以外的字符。

在传递给 parseDouble() 方法之前，尝试从 inputdata 中提取数字

str.replaceAll("[^0-9]", "");