public class MainActivity extends AppCompatActivity {
private Button btn_1;
private Button btn_2;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
btn_1=(Button)findViewById(R.id.anniu);
btn_1.setOnClickListener(new View.OnClickListener()
{
@Override
public void onClick(View view)
{
ViewGroup activity_main=(ViewGroup)findViewById(R.id.activity_main);
btn_2=new Button(MainActivity.this);
btn_2.setText("按钮2");
activity_main.addView(btn_2);
}
});
}
}
错误:找不到符号
符号:变量activity_main
位置:类id