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我正在通過Android在線課程，並且遇到了絆腳石。 當沒有任何內容提交EditText（Number）字段時，我的應用程序崩潰。 我已經嘗試添加異常處理程序的代碼，以我的理解。堅果我仍然有同樣的問題。我正在處理顯示在我的日誌中的異常，如下所示。 Android Studio中的InvocationTargetException條目標記爲Cannot resolve symbol InvocationTargetException。 我不確定這個問題是什麼或者它可能是相關的。EditText上的Android異常處理
代碼：
package com.example.richardcurteis.higherorlower;
import android.os.Bundle;
import android.support.design.widget.FloatingActionButton;
import android.support.design.widget.Snackbar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.EditText;
import android.widget.Toast;
import java.lang.reflect.Method;
import java.util.Random;
public class MainActivity extends AppCompatActivity {
int randomNumber;
EditText getUserInput;
public int getRandomNumber() {
Random randomGenerator = new Random();
randomNumber = randomGenerator.nextInt(10) +1;
return randomNumber;
}
public void higherOrLower(View view) {
String exceptionMessage = "";
try {
getUserInput = (EditText) findViewById(R.id.userInput);
} catch (InvocationTargetException e) {
exceptionMessage = "InvocationTargetException";
} catch (NumberFormatException e) {
exceptionMessage = "NumberFormatException";
} catch (IllegalStateException e) {
exceptionMessage = "IllegalStateException";
}
Toast.makeText(this, exceptionMessage, Toast.LENGTH_LONG).show();
int userInteger = Integer.parseInt(getUserInput.getText().toString());
String message = "";
if (userInteger > randomNumber) {
message = "Lower!";
getUserInput.getText().clear();
} else if (userInteger < randomNumber) {
message = "Higher!";
getUserInput.getText().clear();
} else {
message = "You win!";
getUserInput.getText().clear();
getRandomNumber();
}
Toast.makeText(getApplicationContext(), message, Toast.LENGTH_SHORT).show();
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
FloatingActionButton fab = (FloatingActionButton) findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
randomNumber = getRandomNumber();
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.menu_main, menu);
return true;
}
@Override
public boolean onOptionsItemSelected(MenuItem item) {
// Handle action bar item clicks here. The action bar will
// automatically handle clicks on the Home/Up button, so long
// as you specify a parent activity in AndroidManifest.xml.
int id = item.getItemId();
//noinspection SimplifiableIfStatement
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}
錯誤：
12-28 16:36:23.985 5035-5035/com.example.richardcurteis.higherorlower E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.richardcurteis.higherorlower, PID: 5035
java.lang.IllegalStateException: Could not execute method for android:onClick
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:275)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.reflect.InvocationTargetException
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:270)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
Caused by: java.lang.NumberFormatException: Invalid int: ""
at java.lang.Integer.invalidInt(Integer.java:138)
at java.lang.Integer.parseInt(Integer.java:358)
at java.lang.Integer.parseInt(Integer.java:334)
at com.example.richardcurteis.higherorlower.MainActivity.higherOrLower(MainActivity.java:40)
at java.lang.reflect.Method.invoke(Native Method)
at android.support.v7.app.AppCompatViewInflater$DeclaredOnClickListener.onClick(AppCompatViewInflater.java:270)
at android.view.View.performClick(View.java:5198)
at android.view.View$PerformClick.run(View.java:21147)
at android.os.Handler.handleCallback(Handler.java:739)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:148)
at android.app.ActivityThread.main(ActivityThread.java:5417)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:726)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)