我面临的问题是如何在嵌套的选项卡活动中导航基于Android点击按钮的活动。
我有3个选项卡"仪表板"、"车辆搜索"one_answers"位置搜索"。当我按位置搜索选项卡我得到一个编辑文本(输入邮政编码(然后按按钮(当我按下它时,我应该能找到100英里内的位置不同页面中的邮政编码称为位置搜索结果页面(
我的具体问题是,当我按下"开始"按钮时,应用程序崩溃在我得到的位置之前
我有MainActivity类,它扩展了TabActivity并定义了所有标签
public class MainActivity extends TabActivity
{
public TabHost tabHost;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
tabHost = (TabHost) findViewById(android.R.id.tabhost);
TabHost.TabSpec spec;
Intent intent;
intent = new Intent().setClass(this, DashBoard.class);
spec =
tabHost.newTabSpec("dashboard").setIndicator("DashBoard").setContent(intent);
tabHost.addTab(spec);
intent = new Intent().setClass(this, VehicleSearch.class);
spec =
tabHost.newTabSpec("vehicleSearch").setIndicator("VehicleSearch").setContent(intent);
tabHost.addTab(spec);
intent = new Intent().setClass(this, BranchSearch.class);
spec =
tabHost.newTabSpec("branchSearch").setIndicator("BranchSearch").setContent(intent);
tabHost.addTab(spec);
tabHost.setCurrentTab(3);
}
我还有BranchSearchHelper类,它扩展了ActivityGroup
public class BranchSearchHelper extends ActivityGroup
{
public static BranchSearchHelper branchSearch;
private ArrayList<View> history;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
branchSearch = this;
this.history = new ArrayList<View>();
View view =
getLocalActivityManager().startActivity("BranchSearch", new
Intent(this,BranchSearch.class)
.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP)).getDecorView();
replaceView(view);
}
public void replaceView(View v)
{
// Adds the old one to history
history.add(v);
// Changes this Groups View to the new
View.
setContentView(v);
}
public void back()
{
if(history.size() > 0) {
history.remove(history.size()-1);
setContentView(history.get(history.size()-1));
}
else
{
finish();
}
}
@Override
public void onBackPressed()
{
BranchSearchHelper.branchSearch.back();
return;
}
}
BranchSearch类扩展了活动
public class BranchSearch extends Activity implements OnClickListener
{
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.branchsearch);
Button locSearch = (Button)
findViewById(R.id.btnlocSearch);
locSearch.setOnClickListener(this);
}
public void onClick(View v)
{
// TODO Auto-generated method stub
EditText editText = (EditText)
findViewById(R.id.lsearch);
Bundle bundle = new Bundle();
bundle.putString("zipCode",
editText.getText().toString() );
Intent i = new Intent(getApplicationContext(),
LocationSearchResults.class);
i.putExtras(bundle);
i.addFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP);
View view =
BranchSearchHelper.branchSearch.getLocalActivityManager().startActivity("Locations
Results",i).getDecorView();
BranchSearchHelper.branchSearch.replaceView(view);
}
}
我总是得到异常向抛出的javaNUllPointerexception
View view =
BranchSearchHelper.branchSearch.getLocalActivityManager().startActivity("Locations
Results",i).getDecorView();
因为branchSearch为空
你能告诉我如何跟踪标签并显示吗当我按下go按钮时,所有的定位结果使应用程序崩溃。(我应该更改代码的哪些部分(
有一个名为LocationSearchResults的类,它处理显示所有位置搜索结果
行branchSearch = this;
将使branchSearch成为ActivityGroup。要更正此问题,可以删除此问题,并在onClick声明的底部添加行branchSearch = view;
。