使用android SDK和Eclipse進行Java編程

Question

我正在使用android sdk和eclipse進行Android項目工作。我有我的Java代碼的問題，所以我想知道是否任何人誰知道Java可以幫助我與我的代碼？

這是我的代碼。這些是有問題的錯誤IM - >

public class MainActivity extends ActionBarActivity { 

    private static final String R = null; 
    int counter; 
    Button add, sub; 
    TextView display; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
      super.onCreate(savedInstanceState); 
error -> setContentView(R.layout.activity_main); 
      counter = 0; 
error -> add = (Button) findViewById(R.id.button1); 
error -> sub = (Button) findViewById(R.id.button2); 
error -> display = (TextView) findViewById(R.id.text); 
      add.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       counter++; 
       display.setText("Your Total is" + counter); 
      } 
     }); 
     sub.setOnClickListener(new View.OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       // TODO Auto-generated method stub 
       counter--; 
       display.setText("Your total is " + counter); 
      } 
     }); 
    } 


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

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     // Handle action bar item clicks here. The action bar will 
     // automatically handle clicks on the Home/Up button, so long 
     // as you specify a parent activity in AndroidManifest.xml.`enter code here` 
     int id = item.getItemId(); 
error ->  if (id == R.id.action_settings) { 
      return true; 
     } 
     return super.onOptionsItemSelected(item); 
    } 
} 

Answer 1

爲android.R刪除private static final String R = null;並添加導入：

import android.R; 

你試圖呼籲android.R類的方法，但你不進口它正確地嘗試聲明與String相同名稱的靜態字段。這會讓你的編譯器很傷心。