android - setContentView(R.layout.main);主要是显示错误

Question

这里是编码

package todo.list;

import android.R;
import android.R.layout;
import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Toast;


public class TodolistActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        Button btnSave = (Button)this.findViewById(R.id.button1);
        final EditText txtEdit=(EditText)this.findViewById(R.id.edit);
        btnSave.setOnClickListener(new View.OnClickListener() {

            @Override
            public void onClick(View arg0) {
            // TODO Auto-generated method stub
            String message = txtEdit.getText().toString();
            Toast.makeText(TodolistActivity.this, message, 20).show();
             }
        });

    }

}

我导入了所有类，但仍然显示与我的 main.xml 的连接错误

setContentView(R.layout.main); 

main 显示错误

MAIN CAN NOT BE RESOLVED OR IS NOT A FIELD

Answer 1

删除这些行:

import android.R;
import android.R.layout;

如果使用 Eclipse，git Command(Ctrl)+Shift+O 之后，或替换为

import todo.list.R