Java setContentView(R.layout.activity_main)的oncreate中出错;在安卓工作室
android studio中的currency converter应用程序不断停止,因此我搜索了一点堆栈溢出的原因,这主要是由于一些小错误,并了解了如何检查堆栈跟踪,但我无法解决该问题 在堆栈跟踪中,我看到错误出现在setContentViewR.layout.activity\u main 立即。请帮我解决这个问题。我将在下面附上MainActivity.java和activity_main.xml MainActivity.javaJava setContentView(R.layout.activity_main)的oncreate中出错;在安卓工作室,java,android,xml,android-studio,android-layout,Java,Android,Xml,Android Studio,Android Layout,android studio中的currency converter应用程序不断停止,因此我搜索了一点堆栈溢出的原因,这主要是由于一些小错误,并了解了如何检查堆栈跟踪,但我无法解决该问题 在堆栈跟踪中,我看到错误出现在setContentViewR.layout.activity\u main 立即。请帮我解决这个问题。我将在下面附上MainActivity.java和activity_main.xml MainActivity.java 您需要在应用程序中使用AppCompact主题,因为您正
您需要在应用程序中使用AppCompact主题,因为您正在从MainActivity中扩展AppCompactActivity。将应用程序主题从清单文件更改为AppCompact主题。java.lang.IllegalStateException:您需要在该活动中使用theme.AppCompat主题或子代。@a_local_除我的应用程序外,无人仍在崩溃/停止它是否仍在使用相同的堆栈跟踪崩溃?如果是,请提供您的主题定义以及在AndroidManifest.xmlSo中应用它的位置。答案是肯定的,这确实回答了问题,您应该接受副本。
package edu.udayton.currencyconverter;
import androidx.appcompat.app.AppCompatActivity;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
Spinner sp1, sp2;
EditText ed1;
Button b1;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ed1 = findViewById(R.id.txtamount);
sp1 = findViewById(R.id.spfrom);
sp2 = findViewById(R.id.spto);
b1 = findViewById(R.id.btn1);
String[] from = {"USD"};
ArrayAdapter ad = new ArrayAdapter<String>( this,R.layout.support_simple_spinner_dropdown_item,from);
sp1.setAdapter(ad);
String[] to = {"Euros","Canadian dollars"};
ArrayAdapter ad1 = new ArrayAdapter<String>( this,R.layout.support_simple_spinner_dropdown_item,to);
sp2.setAdapter(ad1);
b1.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Double tot;
Double amount = Double.parseDouble(ed1.getText().toString());
if(sp1.getSelectedItem().toString() == "USD" && sp2.getSelectedItem().toString() == "Euros")
{
tot = amount * 0.89;
Toast.makeText(getApplicationContext(), tot.toString(), Toast.LENGTH_LONG).show();
}
else if(sp1.getSelectedItem().toString() == "USD" && sp2.getSelectedItem().toString() == "Canadian dollars")
{
tot = amount * 1.36;
Toast.makeText(getApplicationContext(), tot.toString(), Toast.LENGTH_LONG).show();
}
}
});
}
}
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
android:gravity="center"
android:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/currency_converter"
android:textSize="30sp" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/enter_the_amount" />
<EditText
android:id="@+id/txtamount"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:autofillHints=""
android:ems="10"
android:hint="@string/amount_in_dollars"
android:inputType="number" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/from" />
<Spinner
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:id="@+id/spfrom"
/>
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/to" />
<Spinner
android:id="@+id/spto"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:spinnerMode="dropdown" />
</LinearLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal">
<Button
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/convert"
android:background="@color/colorPrimaryDark"
android:id="@+id/btn1"
/>
</LinearLayout>
</LinearLayout>
E/AndroidRuntime: FATAL EXCEPTION: main
Process: edu.udayton.currencyconverter, PID: 17237
java.lang.RuntimeException: Unable to start activity
ComponentInfo{edu.udayton.currencyconverter/edu.udayton.currencyconverter.MainActivity}:
java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this
activity.
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2913)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)
Caused by: java.lang.IllegalStateException: You need to use a Theme.AppCompat theme (or descendant) with this activity.
at androidx.appcompat.app.AppCompatDelegateImpl.createSubDecor(AppCompatDelegateImpl.java:696)
at androidx.appcompat.app.AppCompatDelegateImpl.ensureSubDecor(AppCompatDelegateImpl.java:659)
at androidx.appcompat.app.AppCompatDelegateImpl.setContentView(AppCompatDelegateImpl.java:552)
at androidx.appcompat.app.AppCompatActivity.setContentView(AppCompatActivity.java:161)
at edu.udayton.currencyconverter.MainActivity.onCreate(MainActivity.java:24)
at android.app.Activity.performCreate(Activity.java:7136)
at android.app.Activity.performCreate(Activity.java:7127)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1271)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2893)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3048)
at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:78)
at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:108)
at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:68)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1808)
at android.os.Handler.dispatchMessage(Handler.java:106)
at android.os.Looper.loop(Looper.java:193)
at android.app.ActivityThread.main(ActivityThread.java:6669)
at java.lang.reflect.Method.invoke(Native Method)
at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:493)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:858)