单击按钮后如何使文本显示

Question

我正在尝试制作一个简单的应用程序，当您单击按钮文本时会出现该应用程序。但是我遇到了一个问题，当我点击按钮时什么也没有发生。

public class MainActivity extends AppCompatActivity {

    private TextView textView;

    private Button button;

    @Override

    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);

        setContentView(R.layout.activity_main);

        textView = (TextView) findViewById(R.id.textView);

        textView.setMovementMethod(new ScrollingMovementMethod());

        button = (Button) findViewById(R.id.button);

        View.OnClickListener ourOnClickListener = new View.OnClickListener() {

            @Override

            public void onClick(View v) {

                textView.setText("It real sent your at. Amounted all shy set why followed declared. Repeated of endeavor mr position kindness offering ignorant so up. Simplicity are melancholy preference considered saw companions. Disposal on outweigh do speedily in on. Him ham although thoughts entirely drawings. Acceptance unreserved.");

            }

        };

    }

}

XML

  <Button

        android:id="@+id/button"

        android:layout_width="wrap_content"

        android:layout_height="wrap_content"

        android:layout_marginBottom="84dp"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:text="Button"

        app:layout_constraintBottom_toBottomOf="parent"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent" />

    <TextView

        android:id="@+id/textView"

        android:layout_width="374dp"

        android:layout_height="331dp"

        android:layout_marginEnd="8dp"

        android:layout_marginStart="8dp"

        android:layout_marginTop="16dp"

        android:textSize="8sp"

        app:layout_constraintEnd_toEndOf="parent"

        app:layout_constraintStart_toStartOf="parent"

        app:layout_constraintTop_toTopOf="parent" />

Answer 1

您正在启动onClickListener，但您没有将其附加到任何对象。尝试将 附加onClickListener到您的按钮，如下所示：button.setOnClickListener(ourOnClickListener);

Answer 2

单击时什么也没有发生，因为您还没有onClickListener在按钮上设置，您只定义了onClick.&nbsp;在您的onCreate: 中&nbsp;添加这一行button.setOnClickListener(ourOnClickListener)。

Answer 3

解决方案：取而代之的是：View.OnClickListener ourOnClickListener = new View.OnClickListener() {&nbsp; &nbsp; @Override&nbsp; &nbsp; public void onClick(View v) {&nbsp; &nbsp; &nbsp; &nbsp; textView.setText("It real sent your at. Amounted all shy set why followed declared. Repeated of endeavor mr position kindness offering ignorant so up. Simplicity are melancholy preference considered saw companions. Disposal on outweigh do speedily in on. Him ham although thoughts entirely drawings. Acceptance unreserved.");&nbsp; &nbsp; }};像这样写：button.setOnClickListener(new View.OnClickListener) {&nbsp; &nbsp; @Override&nbsp; &nbsp; public void onClick(View v) {&nbsp; &nbsp; &nbsp; &nbsp; textView.setText("It real sent your at. Amounted all shy set why followed declared. Repeated of endeavor mr position kindness offering ignorant so up. Simplicity are melancholy preference considered saw companions. Disposal on outweigh do speedily in on. Him ham although thoughts entirely drawings. Acceptance unreserved.");&nbsp; &nbsp; }};希望能帮助到你。