java - 错误 : class, 接口(interface)，或预期枚举 - Android Studio

Question

错误:需要类、接口(interface)或枚举 - Android Studio

package com.android.wowowowo;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;


public class MainActivity extends AppCompatActivity {

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

        Handler h = new Handler() ;
        h.postDelayed(new Runnable() {
            public void run() {
                startActivity(new Intent(MainActivity.this, MainActivity2.class));
            }

        }, 3000);
    }
    }
}

我想等待 3 秒并更改 Activity

Answer 1

看起来您多了一个大括号。试试这个。

package com.android.wowowowo;

import androidx.appcompat.app.AppCompatActivity;

import android.content.Intent;
import android.os.Bundle;
import android.os.Handler;


public class MainActivity extends AppCompatActivity {

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

        Handler h = new Handler() ;
        h.postDelayed(new Runnable() {
            public void run() {
                startActivity(new Intent(MainActivity.this, MainActivity2.class));
            }

        }, 3000);
    }
}