Activity 跳转 Fragment

Activity 是不能够直接跳转到Fragment的 只能 先跳转到Fragment所挂载的Activity上面 然后在跳转的同时 Activity可以携带一个参数 作为标记，然后在对Fragemnt的宿主Activity设置去显示那个Fragment。 （nTabHost.setCurrentTab(0)）;

上代码：

a.需要跳转的页面 用Intent 携带参数

intent.setClass(SendAlertThirdStepActivity.this,MainActivity.class);
intent.putExtra("extra", "1");
startActivity(intent);

b.Fragment的宿主Activity

@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Fresco.initialize(this);
setContentView(R.layout.activity_main);
mToolbar = (Toolbar) findViewById(R.id.toolbar);
setSupportActionBar(mToolbar);

mLoginPresenter = new LoginPresenter(this, this);

mCheckUpatePresenter = new ChechUpatePresenter(this, this);

mLoginPresenter.doLogin();

<strong>  Intent intent=getIntent();
Value=intent.getStringExtra("extra");
if(Value==null){
tag = 0;
}else{
tag = 1;
}</strong>
mCheckUpatePresenter.doCheckUpdate();
initViews();
}
private void initViews() {
mTabHost = (FragmentTabHost) findViewById(android.R.id.tabhost);
mTabHost.setup(this, getSupportFragmentManager(), android.R.id.tabcontent);
mTabHost.getTabWidget().setDividerDrawable(null);

mTabHost.addTab(
mTabHost.newTabSpec(TAG_MC_FRAGMENT).setIndicator(createTabIndicatorView(R.string.lost_child, R.drawable.tab_lost)),
MissingChildrenFragment.class, null);

mTabHost.addTab(
mTabHost.newTabSpec(TAG_WR_FRAGMENT).setIndicator(createTabIndicatorView(R.string.alert, R.drawable.tab_alert)),
WarningFragment.class, null);

mTabHost.addTab(
mTabHost.newTabSpec(TAG_ST_FRAGMENT).setIndicator(createTabIndicatorView(R.string.mine, R.drawable.tab_myself)),
SettingFragment.class, null);

<strong>  if(tag==0){
mTabHost.setCurrentTab(0);
}else {
mTabHost.setCurrentTab(1);
}</strong>
}

值得注意的是一定要先initViews() 再去设置 mTabHost.setCurrentTable（）的值 要不然 崩溃

mTabHost.setCurrentTab(0);