总结android中Intent的用法：
1. //显示网页
2. Uri uri = Uri.parse("http://google.com");
3. Intent it = new Intent(Intent.ACTION_VIEW, uri);
4. startActivity(it);
5.
6. //显示地图
7. Uri uri = Uri.parse("geo:38.899533,-77.036476");
8. Intent it = new Intent(Intent.ACTION_VIEW, uri);
9. startActivity(it);
16.
17. //路径规划
18.
19. Uri uri = Uri.parse("http://maps.google.com/maps?f=d&saddr=startLat%20startLng&daddr=endLat20endLng&hl=en");
20. Intent it = new Intent(Intent.ACTION_VIEW, uri);
21. startActivity(it);
22. //where startLat, startLng, endLat, endLng are a long with 6 decimals like: 50.123456
23.
24. //打电话
25. //叫出拨号程序
26. Uri uri = Uri.parse("tel:0800000123");
27. Intent it = new Intent(Intent.ACTION_DIAL, uri);
28. startActivity(it);
29.
30. //直接打电话出去
31. Uri uri = Uri.parse("tel:0800000123");
32. Intent it = new Intent(Intent.ACTION_CALL, uri);
33. startActivity(it);
34. //用這個，要在 AndroidManifest.xml 中，加上
35. //<uses-permission >. startActivity(it);