I am a beginner at Android Studio, I tried emulate my application that multiplies two numbers however whenever I am emulating the application on a device, and clicked the button to calculate the two numbers, the application kept on stopping. The device that I am using is Nexus_5x API 26. These are the errors that I encountered in the Run component.
ERROR:
E/SpannableStringBuilder: SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
E/SpannableStringBuilder: SPAN_EXCLUSIVE_EXCLUSIVE spans cannot have a zero length
E/AndroidRuntime: FATAL EXCEPTION: main
Process: com.example.sample, PID: 5372
java.lang.NumberFormatException: For input string: "androidx.appcompat.widget.AppCompatEditText{c3629d8 VFED..CL. ........ 265,118-815,244 #7f0800b8 app:id/firstnumber}"
at java.lang.Integer.parseInt(Integer.java:608)
at java.lang.Integer.parseInt(Integer.java:643)
at com.example.sample.MainActivity$1.onClick(MainActivity.java:26)
at android.view.View.performClick(View.java:6256)
at com.google.android.material.button.MaterialButton.performClick(MaterialButton.java:1119)
at android.view.View$PerformClick.run(View.java:24701)
at android.os.Handler.handleCallback(Handler.java:789)
at android.os.Handler.dispatchMessage(Handler.java:98)
at android.os.Looper.loop(Looper.java:164)
at android.app.ActivityThread.main(ActivityThread.java:6541)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.Zygote$MethodAndArgsCaller.run(Zygote.java:240)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:767)
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<EditText
android:id="@ id/firstnumber"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="45dp"
android:ems="10"
android:hint="Enter First Number"
android:inputType="textPersonName"
android:minHeight="48dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"/>
<EditText
android:id="@ id/secondnumber"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="17dp"
android:ems="10"
android:hint="Enter Second Number"
android:inputType="textPersonName"
android:minHeight="48dp"
app:layout_constraintStart_toStartOf="@ id/firstnumber"
app:layout_constraintTop_toBottomOf="@ id/firstnumber"/>
<Button
android:id="@ id/calculate"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="21dp"
android:text="Calculate"
app:layout_constraintEnd_toEndOf="@ id/secondnumber"
app:layout_constraintStart_toStartOf="@ id/secondnumber"
app:layout_constraintTop_toBottomOf="@ id/secondnumber"/>
<TextView
android:id="@ id/result"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginBottom="236dp"
android:text="Result"
android:textSize="96sp"
android:textStyle="bold"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"/>
</androidx.constraintlayout.widget.ConstraintLayout>
main_activity.java
package com.example.sample;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Button calculate = (Button) findViewById(R.id.calculate);
calculate.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
EditText firstnumber = (EditText) findViewById(R.id.firstnumber);
EditText secondnumber = (EditText) findViewById(R.id.secondnumber);
TextView calculate = (TextView) findViewById(R.id.calculate);
int var1 = Integer.parseInt(String.valueOf(firstnumber));
int var2 = Integer.parseInt(String.valueOf(firstnumber));
int result = Integer.parseInt(String.valueOf(calculate));
result = var1 * var2;
calculate.setText(result "");
}
});
}
}
CodePudding user response：
Change these lines
EditText firstnumber = (EditText) findViewById(R.id.firstnumber);
EditText secondnumber = (EditText) findViewById(R.id.secondnumber);
TextView calculate = (TextView) findViewById(R.id.calculate);
int var1 = Integer.parseInt(String.valueOf(firstnumber));
int var2 = Integer.parseInt(String.valueOf(firstnumber));
int result = Integer.parseInt(String.valueOf(calculate));
result = var1 * var2;
calculate.setText(result "");
to
EditText Firstnumber = findViewById(R.id.firstnumber);
EditText Secondnumber = findViewById(R.id.secondnumber);
TextView Result = findViewById(R.id.result);
int var1 = Integer.parseInt(Firstnumber.getText().toString());
int var2 = Integer.parseInt(Secondnumber.getText().toString());
int result ;
result = var1 * var2;
Result.setText(result "");
Also be sure the input should be Numbers not Letters ...
CodePudding user response：
The very first line of your error tells us everything:
java.lang.NumberFormatException: For input string: "androidx.appcompat.widget.AppCompatEditText{c3629d8 VFED..CL. ........ 265,118-815,244 #7f0800b8 app:id/firstnumber}"
Pay attention to this part: "androidx.appcompat.widget.AppCompatEditText{c3629d8 VFED..CL. ........ 265,118-815,244 #7f0800b8 app:id/firstnumber}".
This is what you get when you are trying to do:
EditText firstnumber = (EditText) findViewById(R.id.firstnumber);
int var1 = Integer.parseInt(String.valueOf(firstnumber));
That's because String.valueOf(firstnumber) will not yield the text that EditText was holding. You need to do firstnumber.getText().toString() to extract the text that user was inputting.