androidmainactivity刷新fragment,选择菜单栏后，如何刷新fragment选项卡？_androidactivity_开发99编程知识库...

通过使用FragmentManager替换旧的fragment 来替换旧的。 现在可以选择一个触发事件的ActiveView菜单项&＃xff0c;并使活动 fragment 替换为当前屏幕下面的屏幕。

解决这个问题的问题主要与识别FragmentManager语法中的正确的R.id.layout 引用有关。 我已经发布了相关的XML和java代码&＃xff0c;希望其他人可以发现它。

MainActivity.xml

xmlns:tools&＃61;"http://schemas.android.com/tools"

android:layout_width&＃61;"match_parent"

android:layout_height&＃61;"match_parent"

android:orientation&＃61;"vertical"

tools:context&＃61;".MainActivity">

**android:id&＃61;"&＃64;&＃43;id/fragment_placeholder"**

android:layout_width&＃61;"match_parent"

android:layout_height&＃61;"match_parent"

android:orientation&＃61;"vertical">

dataCapture.xml

android:tag&＃61;"data_capture"

android:id&＃61;"&＃64;&＃43;id/data_capture"

android:orientation&＃61;"vertical"

android:layout_width&＃61;"fill_parent"

android:layout_height&＃61;"fill_parent">

tools:context&＃61;".dataCapture">

...

style&＃61;"&＃64;style/colorSizeStylexml"

android:layout_width&＃61;"wrap_content"

android:layout_height&＃61;"wrap_content"

android:layout_marginLeft&＃61;"10dip"

android:text&＃61;"Tracklog:"/>

android:id&＃61;"&＃64;&＃43;id/textViewOff"

android:layout_width&＃61;"40dp"

android:layout_height&＃61;"40dp"

android:gravity&＃61;"center"

android:textAppearance&＃61;"?android:attr/textAppearanceMedium"

android:layout_marginRight&＃61;"10dip"

android:text&＃61;"OFF"

android:background&＃61;"#ff000000"

android:textStyle&＃61;"bold"

android:focusableInTouchMode&＃61;"true"

android:textColor&＃61;"#ffffffff"/>

android:id&＃61;"&＃64;&＃43;id/textViewOn"

android:layout_width&＃61;"40dp"

android:layout_height&＃61;"40dp"

android:gravity&＃61;"center"

android:textAppearance&＃61;"?android:attr/textAppearanceMedium"

android:layout_marginRight&＃61;"10dip"

android:text&＃61;"ON"

android:background&＃61;"#ff58ff2d"

android:textStyle&＃61;"bold"/>

.. .

Activity.javapublic class MainActivity extends Activity{

static int iTrackLogFlag &＃61; 0;//if value &＃61; (0) Tracklog is off, if (1) Tracklog is on

public dataCapture dataCapture;

...

&＃64;Override

public void onCreate(Bundle savedInstanceState) {

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

. . .

//put Actionbar in tab mode

ActionBar actionBar &＃61; getActionBar();

actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_TABS);

//set titles for tabs

ActionBar.Tab dataCaptureTab &＃61; actionBar.newTab().setText("DataCapture");

ActionBar.Tab dataEditTab &＃61; actionBar.newTab().setText("DataEdit");

. . .

/*******************************************************************************************

* Create instances of each of the fragments. dataCapture is refreshed several times from

* fragmentManager (ActiveBar menutab for tracklog ON-OFF, and at closure of lookup table

* edit PopupWindows) hence the different format.

*******************************************************************************************/

//Fragment dataCaptureFragment &＃61; new dataCapture();

android.app.FragmentManager fragmentManager &＃61; getFragmentManager();

android.app.FragmentTransaction fragmentTransaction &＃61; fragmentManager.beginTransaction();

dataCapture dataCapture &＃61; new dataCapture();

fragmentTransaction.add(dataCapture,"data_capture");

fragmentTransaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);

fragmentTransaction.addToBackStack(null);

fragmentTransaction.commit();

Fragment dataEditFragment &＃61; new dataEdit();

. . .

//attach those fragment instances to their respective tabs

dataCaptureTab.setTabListener(new MyTabsListener(dataCapture));

dataEditTab.setTabListener(new MyTabsListener(dataEditFragment));

. . .

//add each tab to the ActionBar

actionBar.addTab(dataCaptureTab);

actionBar.addTab(dataEditTab);

. . .

if (savedInstanceState &＃61;&＃61; null){//...do nothing

}else if (savedInstanceState!&＃61; null){

actionBar.setSelectedNavigationItem(savedInstanceState.getInt(TAB_KEY_INDEX,0));

}

}

&＃64;Override

public boolean onCreateOptionsMenu(Menu menu) {

MenuInflater inflater &＃61; getMenuInflater();

inflater.inflate(R.menu.corax, menu);

return true;

}

&＃64;Override

public boolean onOptionsItemSelected(MenuItem item) {

switch(item.getItemId()) {

case R.id.menuitem_tracklogOnOff:

openTracklogDialog();//opens a dialog box...trying to minimize clutter in the toolbar.

//

return true;

}

return false;

}

private void openTracklogDialog(){

AlertDialog.Builder TracklogDialog &＃61; new AlertDialog.Builder(this);

TracklogDialog.setTitle("Tracklog control");

TracklogDialog.setMessage("Press a button below to start or stop the tracklog.");

TracklogDialog.setPositiveButton("STOP",new DialogInterface.OnClickListener() {

&＃64;Override

public void onClick(DialogInterface dialog, int which) {

iTrackLogFlag &＃61; 0;//"0" means OFF, sets button on frontend to black w/white letters OFF

}

});

TracklogDialog.setNegativeButton("START",new DialogInterface.OnClickListener() {

&＃64;Override

public void onClick(DialogInterface dialog, int which) {

//Toast.makeText(getApplicationContext(),"Tracklog started.", Toast.LENGTH_LONG).show();

iTrackLogFlag &＃61; 1;//"1" means ON, sets button to green w/black letters

Fragment currentFragment &＃61; (dataCapture)getFragmentManager().findFragmentByTag("data_capture");

if(currentFragment &＃61;&＃61; null) {

Toast.makeText(appContext,"This &＃61;&＃61; NULL.", Toast.LENGTH_SHORT).show();

currentFragment &＃61; new dataCapture();

}else if(currentFragment!&＃61; null){

getFragmentManager().popBackStack(null, FragmentManager.POP_BACK_STACK_INCLUSIVE);

getFragmentManager().beginTransaction().replace(R.id.fragment_placeholder, new dataCapture(),"data_capture").addToBackStack(null).commit();

Toast.makeText(appContext,"This!&＃61; NULL. currentFragment &＃61;"&＃43;currentFragment&＃43;", dataCapture &＃61;"&＃43;dataCapture&＃43;".", Toast.LENGTH_LONG).show();

}

dialog.dismiss();

}

});

AlertDialog alert &＃61; TracklogDialog.create();

alert.show();

}

}