路从今夜白的博客

布局文件：xmlns:android="http://schemas.android.com/apk/res/android" xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent" android:layout_height="match_parent"

public class MainActivity extends Activity { private String str; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setCont