设置menu,要求出现如图效果
代码编写过程中代码无错,但运行时产生Failed to compile values file.错误。
附代码:
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto">
<item
android:id="@+id/menu888"
android:orderInCategory="100"
android:icon="@drawable/ccut"
android:title="@string/menu123"
app:showAsAction="always"
/>
</menu>
<?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"
android:background="#000000"
tools:context=".MainActivity">
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/textview2"
android:textSize="23sp"
android:textColor="#ffffff"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.0"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:layout_constraintVertical_bias="0.414" />
</androidx.constraintlayout.widget.ConstraintLayout>
package com.example.menurepeat2;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
public class MainActivity extends AppCompatActivity {
TextView textView;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
textView=findViewById(R.id.textView3);
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.main,menu);
menu.add(1,1,1,"移动开发技术");
menu.add(1,2,2,"python");
menu.add(1,3,3,"英语");
menu.add(1,4,4,"高数");
return super.onCreateOptionsMenu(menu);
}
@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {
String data=item.getTitle().toString();
switch (item.getItemId()){
case 1:
case 2:
case 3:
case 4:
textView.setText("您选择了:"+data);break;
}
return super.onOptionsItemSelected(item);
}
}