Question

我正在尝试使用Android按钮“Play”构建一个简单的应用程序。在MainActivty.java文件中，我收到以下代码的错误，所以我需要在这里纠正什么？

package com.example.simplemusicplayer;

import android.os.Bundle;
import android.app.Activity;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;

public class MainActivity extends Activity {

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


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.main, menu);
    return true;
}
}

Button playButton=(Button) findViewById(R.id.button1);
playButton.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v){
    //TODO Auto generated method stub
    Toast.makeText(MainActivity.this,"Starting to play",Toast.LENGTH_SHORT).show();       
}
});
}
}

Answer 1

移动

Button playButton=(Button) findViewById(R.id.button1);
playButton.setOnClickListener(new OnClickListener(){
@Override
public void onClick(View v){
    //TODO Auto generated method stub
    Toast.makeText(MainActivity.this,"Starting to play",Toast.LENGTH_SHORT).show();       
}
});

在onCreate()内。

从}的末尾删除额外的onCreateOptionsMenu。

我还建议你阅读Building Your First Android App，这是一本很好的指南，可以教你基础知识。

Answer 2

试试这段代码

package com.example.simplemusicplayer;

import android.app.Activity;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.Toast;

public class MainActivity extends Activity {

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

        Button playButton = (Button) findViewById(R.id.button1);
        playButton.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                // TODO Auto generated method stub
                Toast.makeText(MainActivity.this, "Starting to play",
                        Toast.LENGTH_SHORT).show();
            }
        });
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }
}

构建android应用程序

2 个答案: