常用Intent

1.打开浏览器

Uri uri = Uri.parse("http://www.baidu.com");
Intent intent = new Intent(Intent.ACTION_VIEW, uri);
startActivity(intent); 

2.外呼电话—拨号界面

Uri uri = Uri.parse("tel:123456789");
Intent intent = new Intent(Intent.ACTION_DIAL, uri);
startActivity(intent);

3.外呼电话—直接拨打

Uri uri = Uri.parse("tel:123456789");
Intent intent = new Intent(Intent.ACTION_CALL, uri);
startActivity(intent);

4.发送短信—调起短信页面

Intent intent = new Intent(Intent.ACTION_VIEW, uri);
intent.putExtra("sms_body", "SMS text"); 
intent.setType("vnd.android-dir/mms-sms");
startActivity(intent);

 5. 跳转到桌面,经常用于屏蔽后退键直接回到桌面

Intent intent = new Intent();
intent.setAction(Intent.ACTION_MAIN);
intent.addCategory(Intent.CATEGORY_HOME);
intent.addCategory(Intent.CATEGORY_DEFAULT);
intent.addCategory(Intent.CATEGORY_MONKEY);
startActivity(intent);

 屏蔽后退键,直接回到桌面

@Override
public void onBackPressed() {
    super.onBackPressed();

    Intent intent = new Intent();
    intent.setAction(Intent.ACTION_MAIN);
    intent.addCategory(Intent.CATEGORY_HOME);
    intent.addCategory(Intent.CATEGORY_DEFAULT);
    intent.addCategory(Intent.CATEGORY_MONKEY);
    startActivity(intent);
}