Android app development

1. 如何引进一个existing Android project:
1. 先新建一个Android hello world project，theme记得选none
2. Import Android project之后修改project.properties为步骤1的内容
比如
target=android-19
android.library.reference.1=../appcompat_v7

2. 常用组件:
Toast:

Context context = getApplicationContext();
    Toast toast = Toast.makeText(context, "hihi", Toast.LENGTH_SHORT);
    toast.show();