Question

我正在制作一个距离转换器应用程序。代码完美编译并运行。但是，当我点击“计算”按钮时，它会显示

应用程序转换器（进程com.example.converter）已停止出乎意料地。请再试一次

Logcat截图：

MainActivity.java代码是：

package com.example.converter;
import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.RadioButton;
import android.widget.Toast;

public class MainActivity extends Activity {

    // public var
    private EditText text;

    // default func
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        // findViewById = Finds a view that was identified by the id attribute
        // from the XML that was processed in onCreate(Bundle).
        // (EditText) = typecast
        text = (EditText) findViewById(R.id.editText1);
    }

    // default func
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    /*
     * Will be executed by clicking on the calculate button because we assigned
     * "calculate" to the "onClick" Property!
     */
    public void calculate(View view) {

        RadioButton mileButton = (RadioButton) findViewById(R.id.radio0);
        RadioButton kmhButton = (RadioButton) findViewById(R.id.radio1);
        // if the text field is empty show the message "enter a valid number"
        if (text.getText().length() == 0) {
            // Toast = focused floating view that will be shown over the main
            // application
            Toast.makeText(this, "enter a valid number", Toast.LENGTH_LONG)
                    .show();
        } else {
            //parse input Value from Text Field
            double inputValue = Double.parseDouble(text.getText().toString());
            // convert to...
            if (mileButton.isChecked()) {
                text.setText(String.valueOf(convertToMiles(inputValue)));
                // uncheck "to miles" Button
                mileButton.setChecked(false);
                // check "to km/h" Button
                kmhButton.setChecked(true);
            } else { /* if kmhButton isChecked() */
                text.setText(String.valueOf(convertToKmh(inputValue)));
                // uncheck "to km/h" Button
                kmhButton.setChecked(false);
                // check "to miles" Button
                mileButton.setChecked(true);
            }
        }
    }

    private double convertToMiles(double inputValue) {
        // convert km/h to miles
        return (inputValue * 1.609344);
    }

    private double convertToKmh(double inputValue) {
        // convert miles to km/h
        return (inputValue * 0.621372);
    }
}

Answer 1

在代码中，您在XML中说calculate(View v)（我假设您定义了onClick），您说的是calc。所以基本上把它改成calculate，它应该有效。

Android应用程序已停止响应

1 个答案: