注：以下知识本人在代码中用到的，还有其他方法
一、int类型
发送端：
CR.setTextSize(Integer.parseInt(fontsizespinner.getSelectedItem().toString()));
Bundle bundle = new Bundle();
bundle.putInt("newSize", CR.getTextSize());
Intent mIntent = new Intent(FontSetActivity.this,DetailActivity.class);
mIntent.putExtras(bundle);
接收端：
Bundle bundle=this.getIntent().getExtras();
int newSize = bundle.getInt("newSize");
二、String类型
发送端：
Intent intent = new Intent(FontSetActivity.this,DetailActivity.class);
intent.putExtras("asd1", asd);
接收端：
String asd = this.getIntent().getExtras("asd1");
三、Object类型
发送端：
Intent intent = new Intent(FontSetActivity.this,DetailActivity.class);
Book book = new Book();
book.setName("法老的宠妃");
book.setAuthor("Brooks");
Bundle bundle = new Bundle();
bundle.putParcelable("book", book);
intent.putExtras(bundle);
startActivity(intent);
接收端：
TextView text = new TextView(this);
Book book = (Book) getIntent().getParcelableExtra("book");
text.setText("name:"+book.getName()+"/nautor:"+book.getAuthor()+"/ntime:"+book.getTime());
setContentView(text);