Android:Layout.addView()不起作用

Question

当我尝试运行以下代码时出现错误.模拟器给我这个错误消息,然后app force关闭: 应用程序意外停止.怎么了？

import edu.chl.dat255.bluebanana.R;
import android.app.Activity;
import android.os.Bundle;
import android.widget.LinearLayout;
import android.widget.TextView;

public class ProMan extends Activity {
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        LinearLayout layout = (LinearLayout) findViewById(R.layout.main);

        TextView t = new TextView(getApplicationContext());
        t.setText("Hello world");
        layout.addView(t);
    }
}

Answer 1

  LinearLayout layout = (LinearLayout) findViewById(R.id.mainLayout);

In your xml file main xml layout android:id="@+id/mainLayout"