问题
I am trying to make an app with tabs at the top that link a website too each one, such as a computer that uses tabs in safari or firefox. What I am trying to do is implement an add and delete class that will allow the user to delete a tab if wanted and add another that will link to a different website. Any help would be greatly appreciated.
Here is the main java file.
public class UniversityofColorado extends TabActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
TabHost host=getTabHost();
host.addTab(host.newTabSpec("one")
.setIndicator("Google")
.setContent(new Intent(this, Hello.class)));
host.addTab(host.newTabSpec("two")
.setIndicator("Colorado Main Site")
.setContent(new Intent(this, ColoradoMainSiteBrowser.class)));
host.addTab(host.newTabSpec("three")
.setIndicator("CULearn")
.setContent(new Intent(this, CULearnBrowser.class)));
host.addTab(host.newTabSpec("four")
.setIndicator("CULink")
.setContent(new Intent(this, CULinkBrowser.class)));
host.addTab(host.newTabSpec("five")
.setIndicator("MyCUInfo")
.setContent(new Intent(this, MyCUInfoBrowser.class)));
host.addTab(host.newTabSpec("six")
.setIndicator("Campus Map")
.setContent(new Intent(this, CampusBrowser.class)));
host.addTab(host.newTabSpec("Seven")
.setIndicator("Notes")
.setContent(new Intent(this, Notepadv3.class)));
}
// Inflates menu when "menu Key" is pressed
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
}
This is one of the java files that the main java file uses:
public class ColoradoMainSiteBrowser extends Activity {
WebView webview;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
webview = (WebView) findViewById(R.id.webview);
webview.setWebViewClient(new HelloWebViewClient());
webview.getSettings().setJavaScriptEnabled(true);
webview.loadUrl("http://colorado.edu/");
}
private class HelloWebViewClient extends WebViewClient {
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url)
{
view.loadUrl(url);
return true;
}
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && webview.canGoBack()) {
webview.goBack();
return true;
}
return super.onKeyDown(keyCode, event);
}
}
How would I implement the add and delete buttons to have this same format when the new tabs were added.
回答1:
In order to achieve the desired effect, you probably need to drop an activity for each tab approach.
Instead, you would create a "default" view that you can use to all websites that accept the URL as a parameter.
Then, instead of "intenting" a new activity to each tab, you Inflate that view to the new tab, passing the URL as a parameter.
To create and delete tabs dinamically would be easy. A simple button that Inflates/removes the view would sufice.
XML
res/layout/main.xml
<TabHost xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@android:id/tabhost"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<LinearLayout
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp">
<TabWidget
android:id="@android:id/tabs"
android:layout_width="fill_parent"
android:layout_height="wrap_content" />
<FrameLayout
android:id="@android:id/tabcontent"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:padding="5dp" />
</LinearLayout>
</TabHost>
res/layout/tab.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
android:layout_width="fill_parent"
android:layout_height="fill_parent"
xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
>
<TextView
android:id="@+id/url_tv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="HELLO TAB!"
>
</TextView>
</LinearLayout>
res/menu/menu.xml
<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">
<item android:enabled="true" android:visible="true" android:icon="@android:drawable/ic_menu_add" android:title="Add Website" android:titleCondensed="add" android:id="@+id/add"></item>
<item android:titleCondensed="Delete" android:enabled="true" android:visible="true" android:icon="@android:drawable/ic_menu_delete" android:id="@+id/delete" android:title="Delete Website"></item>
</menu>
JAVA CODE
main.java
import android.app.TabActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.TabHost;
import android.widget.TextView;
public class Main extends TabActivity implements TabHost.TabContentFactory {
TabHost tabHost;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
this.tabHost = getTabHost(); // The activity TabHost
tabHost.addTab(tabHost.newTabSpec("http://www.google.com/").setIndicator("Google").setContent(this));
tabHost.addTab(tabHost.newTabSpec("http://www.stackoverflow.com/").setIndicator("StackOverflow").setContent(this));
}
public View createTabContent(String tag) {
// Inflation per se.
// we don't return anything yet so we can work with this view
View tab = View.inflate(this, R.layout.tab, null);
// Here we work with the view
// in this case we set the textview to match our tag
// its a good way to parse arguments to the new tab
TextView tv = (TextView) tab.findViewById(R.id.url_tv);
tv.setText(tag);
//After work we can return view
return tab;
}
private void addMethod(String webSiteURL, String webSiteName) {
// Find a way that suits you to pass arguments to here
tabHost.addTab(tabHost.newTabSpec(webSiteURL).setIndicator(webSiteName).setContent(this));
}
private void deleteMethod() {
// Create a way to decide which tab to delete.
// for instance, FindViewByTag is a method of ViewGroup and works
// then call the parent of the view with
// ViewGroup parent = (ViewGroup) viewToDelete.getParent();
// finally use oarent.removeView(viewToDelete);
}
// Inflates menu when "menu Key" is pressed
@Override
public boolean onCreateOptionsMenu(Menu menu) {
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.menu, menu);
return true;
}
// This method is called once the menu is selected
@Override
public boolean onOptionsItemSelected(MenuItem item) {
switch (item.getItemId()) {
case R.id.add:
// These variable is created artificially so that something is passed to our addMethod
// You should find a way to pass these argument to our method
// can be a dialog screen, or getting the URL from somewhere
// its your call
String webSiteURL = "http://www.evonytools.org/";
String webSiteName = "Tivie's Tools";
addMethod(webSiteURL, webSiteName);
case R.id.delete:
deleteMethod();
break;
}
return true;
}
}
来源：https://stackoverflow.com/questions/4309964/how-to-implement-a-command-that-allows-user-to-add-and-delete-tabs-in-the-applic