Question

我的应用程序正常工作但是当我添加启动画面时出现错误，我不知道该怎么做或如何解决它

错误是

java.lang.NullPointerException: Attempt to invoke virtual method 'void android.widget.TextView.setOnClickListener(android.view.View$OnClickListener)' on a null object reference

我的MainActivity

public class MainActivity extends AppCompatActivity {

private final int SPLASH_DISPLAY_LENGTH = 4000;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_splash);


    new Handler().postDelayed(new Runnable() {

        @Override
        public void run() {
            Intent splashIntent = new Intent(MainActivity.this , SplashActivity.class);

            MainActivity.this.startActivity(splashIntent);
            MainActivity.this.finish();
        }
    },SPLASH_DISPLAY_LENGTH);




    // Find the View that shows the numbers category
    TextView numbers = (TextView) findViewById(R.id.numbers);

    // Set a click listener on that View
    numbers.setOnClickListener(new OnClickListener() {
        // The code in this method will be executed when the numbers category is clicked on.
        @Override
        public void onClick(View view) {
            // Create a new intent to open the {@link NumbersActivity}
            Intent numbersIntent = new Intent(MainActivity.this, NumbersActivity.class);

            // Start the new activity
            startActivity(numbersIntent);
        }
    });

和activity_splash

  <?xml version="1.0" encoding="utf-8"?>
  <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/category_phrases"
tools:context="com.example.android.miwok.SplashActivity">

<ImageView
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:src="@mipmap/nemo"
    />

<TextView
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="HELLO NEMO"
    android:textColor="#FFF"
    android:textSize="40sp"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="30dp"
    android:layout_marginLeft="40dp"
    android:fontFamily="casual"
    android:textStyle="bold|italic"

    />

SplashActivity 

public class SplashActivity extends AppCompatActivity {

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

有什么可以解决的吗？

Answer 1

您忘记在textview中设置ID

<TextView
    android:id="@+id/numbers"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:text="HELLO NEMO"
    android:textColor="#FFF"
    android:textSize="40sp"
    android:layout_alignParentBottom="true"
    android:layout_marginBottom="30dp"
    android:layout_marginLeft="40dp"
    android:fontFamily="casual"
    android:textStyle="bold|italic"

/>

尝试调用虚拟方法'void android.widget.TextView.setOnClickListener

1 个答案: