导致相同活动的两个按钮

Question

[在Android中尝试使用两个不同的按钮调用两个不同的活动时遇到问题。

即使两个按钮应调用不同的活动，它们也会导致指向相同的活动（Statistics.class）。

这是我的XML代码：

<?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">

    <FrameLayout
        android:layout_width="0dp"
        android:layout_height="0dp"
        android:background="@color/colorPrimary"
        android:layout_marginBottom="128dp"
        app:layout_constraintBottom_toTopOf="@+id/startBtn"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent">
        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="vertical"
            android:gravity="center">

            <androidx.appcompat.widget.AppCompatImageView
                android:id="@+id/tum_logo"
                android:layout_width="match_parent"
                android:layout_height="100dp"
                android:src="@drawable/tum_logo">
            </androidx.appcompat.widget.AppCompatImageView>

            <TextView
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:layout_gravity="center"
                android:layout_marginTop="10dp"
                android:text="das Quiz"
                android:textColor="@android:color/white"
                android:textSize="42dp"
                android:textStyle="bold" />

        </LinearLayout>
    </FrameLayout>

    <Button
        android:id="@+id/startBtn"
        android:layout_width="150dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="32dp"
        android:background="@drawable/btn_rounded_corners"
        android:backgroundTint="@color/colorPrimary"
        android:text="Quiz starten"
        android:textColor="@android:color/white"
        android:textStyle="bold"
        android:onClick="onClick"
        app:layout_constraintBottom_toTopOf="@+id/statisticsBtn"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <Button
        android:id="@+id/statisticsBtn"
        android:layout_width="150dp"
        android:layout_height="wrap_content"
        android:layout_marginBottom="64dp"
        android:text="Statistiken"
        android:textStyle="bold"
        android:background="@drawable/btn_rounded_corners"
        android:backgroundTint="#8A8A8A"
        android:textColor="@android:color/white"
        android:onClick="onClick"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>

这是相应的Java代码：

public class MainActivity extends AppCompatActivity implements View.OnClickListener {
    Button startBtn, statisticsBtn;
    Intent intent = null;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        startBtn = (Button) findViewById(R.id.startBtn);
        statisticsBtn = (Button) findViewById(R.id.statisticsBtn);
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if(keyCode == KeyEvent.KEYCODE_BACK){
            System.exit(0);
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

    @Override
    public void onClick(View v) {
        switch (v.getId()){
            case R.id.startBtn:
                intent = new Intent(this, Semester.class);
                startActivity(intent);
                Toast.makeText(this, "startBtn", Toast.LENGTH_SHORT).show();
                this.finish();
            case R.id.statisticsBtn:
                intent = new Intent(this, Statistics.class);
                startActivity(intent);
                Toast.makeText(this, "statisticsBtn", Toast.LENGTH_SHORT).show();
                this.finish();
        }
    }
}

吐司表示，在单击startBtn之后也单击了statisticsBtn，但我不明白为什么。

Answer 1

您忘记在案例结束后添加break;。

switch (v.getId()){
            case R.id.startBtn:
                intent = new Intent(this, Semester.class);
                startActivity(intent);
                Toast.makeText(this, "startBtn", Toast.LENGTH_SHORT).show();
                this.finish();
                break;
            case R.id.statisticsBtn:
                intent = new Intent(this, Statistics.class);
                startActivity(intent);
                Toast.makeText(this, "statisticsBtn", Toast.LENGTH_SHORT).show();
                this.finish();
                break;
        }