我正在构建一个转换不同单位的应用程序，我收到了“Fatal exception main”消息，但我的代码运行到启动应用程序并显示四个按钮，但当你点击任一按钮时崩溃。我没有其他错误。
MainActivity：
import android.os.Bundle;
import android.app.Activity;
import android.content.Intent;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
public class MainActivity extends Activity {
public final static String EXTRA_MESSAGE = "com.lacrym0sadevelopment.convertix";
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
@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;
}
public void unitLength(View view) {
Intent intent = new Intent(this, CalculateLength.class);
EditText editText = (EditText) findViewById(R.id.button1);
String message = editText.getText().toString();
intent.putExtra(EXTRA_MESSAGE, message);
startActivity(intent);
}// unitLength
public void unitWeight(View view) {
Intent intent = new Intent(this, CalculateWeight.class);
startActivity(intent);
}// unitWeigth
public void unitVolume(View view) {
Intent intent = new Intent(this, CalculateVolume.class);
startActivity(intent);
}// unitVolume
public void unitSpeed(View view) {
Intent intent = new Intent(this, CalculateSpeed.class);
startActivity(intent);
}// unitSpeed
}// MainActivity
CalculateLength：
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 CalculateLength extends Activity {
private EditText text;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
text = (EditText) findViewById(R.id.editText1);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void calculate(View view) {
RadioButton feetButton = (RadioButton) findViewById(R.id.radio0);
RadioButton metreButton = (RadioButton) findViewById(R.id.radio1);
RadioButton kmButton = (RadioButton) findViewById(R.id.radio2);
RadioButton milesButton = (RadioButton) findViewById(R.id.radio3);
if (text.getText().length() == 0) {
Toast.makeText(this, "Enter a Value", Toast.LENGTH_LONG).show();
} else {
double inputValue = Double.parseDouble(text.getText().toString());
if (feetButton.isChecked()) {
text.setText(String.valueOf(convertToFeet(inputValue)));
feetButton.setChecked(true);
metreButton.setChecked(false);
kmButton.setChecked(false);
milesButton.setChecked(false);
}
if (metreButton.isChecked()) {
text.setText(String.valueOf(convertToMetre(inputValue)));
feetButton.setChecked(false);
metreButton.setChecked(true);
kmButton.setChecked(false);
milesButton.setChecked(false);
}
if (kmButton.isChecked()) {
text.setText(String.valueOf(convertToKm(inputValue)));
feetButton.setChecked(false);
metreButton.setChecked(false);
kmButton.setChecked(true);
milesButton.setChecked(false);
}
if (milesButton.isChecked()) {
text.setText(String.valueOf(convertToMiles(inputValue)));
feetButton.setChecked(false);
metreButton.setChecked(false);
kmButton.setChecked(false);
milesButton.setChecked(true);
}
}
}
private double convertToFeet(double inputValue) {
return (inputValue * 3.2808);
}
private double convertToMetre(double inputValue) {
return (inputValue / 3.2808);
}
private double convertToKm(double inputValue) {
return (inputValue / 0.62137);
}
private double convertToMiles(double inputValue) {
return (inputValue * 0.62137);
}
}//CalculateLength
Logcat输出：
01-10 04:58:34.599: E/AndroidRuntime(1155): FATAL EXCEPTION: main
01-10 04:58:34.599: E/AndroidRuntime(1155): Process: com.lacrym0sadevelopment.convertix, PID: 1155
01-10 04:58:34.599: E/AndroidRuntime(1155): java.lang.IllegalStateException: Could not execute method of the activity
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.view.View$1.onClick(View.java:3814)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.view.View.performClick(View.java:4424)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.view.View$PerformClick.run(View.java:18383)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.os.Handler.handleCallback(Handler.java:733)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.os.Handler.dispatchMessage(Handler.java:95)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.os.Looper.loop(Looper.java:137)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.app.ActivityThread.main(ActivityThread.java:4998)
01-10 04:58:34.599: E/AndroidRuntime(1155): at java.lang.reflect.Method.invokeNative(Native Method)
01-10 04:58:34.599: E/AndroidRuntime(1155): at java.lang.reflect.Method.invoke(Method.java:515)
01-10 04:58:34.599: E/AndroidRuntime(1155): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
01-10 04:58:34.599: E/AndroidRuntime(1155): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
01-10 04:58:34.599: E/AndroidRuntime(1155): at dalvik.system.NativeStart.main(Native Method)
01-10 04:58:34.599: E/AndroidRuntime(1155): Caused by: java.lang.reflect.InvocationTargetException
01-10 04:58:34.599: E/AndroidRuntime(1155): at java.lang.reflect.Method.invokeNative(Native Method)
01-10 04:58:34.599: E/AndroidRuntime(1155): at java.lang.reflect.Method.invoke(Method.java:515)
01-10 04:58:34.599: E/AndroidRuntime(1155): at android.view.View$1.onClick(View.java:3809)
01-10 04:58:34.599: E/AndroidRuntime(1155): ... 11 more
01-10 04:58:34.599: E/AndroidRuntime(1155): Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText
01-10 04:58:34.599: E/AndroidRuntime(1155): at com.lacrym0sadevelopment.convertix.MainActivity.unitLength(MainActivity.java:31)
01-10 04:58:34.599: E/AndroidRuntime(1155): ... 14 more
答案 0 :(得分：1)
您似乎正在尝试将Button投射到EditText：
EditText editText = (EditText) findViewById(R.id.button1);
导致
Caused by: java.lang.ClassCastException: android.widget.Button cannot be cast to android.widget.EditText