Android 的 Tab 不能正常运行
其他问答
1
在 TabActivity 有一个 TabHost,在 TabHost 中有两个选项卡,每个选项卡都有自己的intent。如果一个 tab 改变,在我检测之前,这个 intent 的 onResume()方法被销毁。如何解决这个问题呢? TabActivity code:
public class TabHostActivity extends TabActivity {
static final int SHOW_SHARE_ACTIVITY = 0;
static final int SHOW_LOGIN_ACTIVITY = 1;
private TabHost tabHost;
private ImageButton composeImageButton;
private SharedPreferences prefs;
private Bundle b;
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_NO_TITLE);
setContentView(R.layout.tabhostactivity);
prefs = getSharedPreferences(Constants.PREFS_NAME, 0);
//Setup the ActionBar
composeImageButton = (ImageButton) findViewById(R.id.composeImageButton);
composeImageButton.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View v) {
if(prefs.getBoolean("isLoggedIn", false))
{
showShareActivity();
}
else
{
Intent intent = new Intent(TabHostActivity.this, LoginActivity.class);
startActivityForResult(intent, SHOW_LOGIN_ACTIVITY);
}
}
});
b = new Bundle();
//Setup the Tabs
Resources res = getResources(); // Resource object to get Drawables
tabHost = getTabHost(); // The activity TabHost
tabHost.setOnTabChangedListener(new OnTabChangeListener() {
@Override
public void onTabChanged(String arg0) {
if(tabHost.getCurrentTab() == 0) //Check if the Watchlist tab was clicked so we can prompt login
{
//Toast toast = Toast.makeText(getApplicationContext(), "TRENDING = YES", Toast.LENGTH_SHORT);
//toast.show();
b.putBoolean("isTrendingTab",true);
}
else
{
Toast toast = Toast.makeText(getApplicationContext(), "TRENDING = NO", Toast.LENGTH_SHORT);
toast.show();
b.putBoolean("isTrendingTab",false);
}
}
});
TabHost.TabSpec spec; // Resusable TabSpec for each tab
Intent intent; // Reusable Intent for each tab
// Create an Intent to launch an Activity for the tab (to be reused)
intent = new Intent().setClass(this, ARActivity.class);
intent.putExtras(b);
// Initialize a TabSpec for each tab and add it to the TabHost
spec = tabHost.newTabSpec("trending").setIndicator("Trending",res.getDrawable(R.drawable.icon)).setContent(intent);
tabHost.addTab(spec);
// Do the same for the other tabs
intent = new Intent().setClass(this, WatchlistActivity.class);
intent.putExtras(b);
spec = tabHost.newTabSpec("watchlist").setIndicator("Watchlist",res.getDrawable(R.drawable.icon)).setContent(intent);
tabHost.addTab(spec);
tabHost.setCurrentTab(0);
}
private void showShareActivity()
{
Intent intent = new Intent(TabHostActivity.this, ShareActivity.class);
startActivityForResult(intent, SHOW_SHARE_ACTIVITY);
}
protected void onActivityResult(int requestCode, int resultCode, Intent data) {
if(requestCode == SHOW_LOGIN_ACTIVITY)
{
//Login was successful so lets show the compose box!
if (resultCode == RESULT_OK) {
showShareActivity();
}
}
}
}
这是其中一个 activity 中intent里的 onResume 方法:
public void onResume()
{
super.onResume();
Bundle bundle = getIntent().getExtras();
if(bundle.getBoolean("isTrendingTab"))
{
Toast toast = Toast.makeText(getApplicationContext(), "TRENDING!", Toast.LENGTH_SHORT);
toast.show();
}
else
{
Toast toast = Toast.makeText(getApplicationContext(), "WATCHLIST!", Toast.LENGTH_SHORT);
toast.show();
}
}
-
不需要使用 onTabChanged()
Intent intent = new Intent(action) // see notes below about "action" .setClass(this, ARActivity.class) .putExtra("isTrendingTab", true); TabHost.TabSpec spec = tabHost.newTabSpec("trending") .setIndicator("trending", getResources().getDrawable(drawableId)) .setContent(intent); tabHost.addTab(spec);
在 onResume()方法中:
if (getIntent().getBooleanExtra("isTrendingTab", false)) {...
-
你是想在 intent 上输出:
b.putBoolean("isTrendingTab",true);
或者 false。通过检测改变来开启。 这是错误的方法。更改事件总是会发生在活动启动后,你应该做的逻辑也不同。
发表回复