強制關閉錯誤

Question

此程序的強制關閉問題是什麼？

public class MyActivity extends Activity { 

    TextView t=(TextView)findViewById(R.id.textView1); 
    Button r=(Button)findViewById(R.id.button2); 
     private OnClickListener i=new OnClickListener(){ 

     @Override 
     public void onClick(View arg0) { 
      // TODO Auto-generated method stub 
      t.setText("fghffghfhgf"); 
     }  
     }; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 
     r.setOnClickListener(i); 
    } 
} 

Answer 1

你需要讓你的TextView和Button充氣佈局之後。

public class MyActivity extends Activity { 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     //here inflate the layout 
     setContentView(R.layout.main); 

     //now you can get your widgets 
     final TextView t= (TextView)findViewById(R.id.textView1); 
     Button r=(Button)findViewById(R.id.button2); 
     r.setOnClickListener(new OnClickListener(){ 

     @Override 
     public void onClick(View arg0) { 
      // TODO Auto-generated method stub 
      t.setText("fghffghfhgf");  
     } 

     }; 
    ); 
    } 
} 

我真的建議您檢查this來構建您的第一個應用程序。