Question

我需要在活动中放置类似浏览器的模块。我正在使用fragmentTabHost。添加按钮将在fragmentTabHost中添加选项卡，并且有关闭按钮以关闭fragmentTabHost中的选项卡。。但它可以正常工作3到4次，但之后它会抛出NullPointerException

我认为关闭标签后会出现此异常，即添加新标签时没有错误。但是，如果我尝试选择上一个或后一个最后一个选项卡，则关闭选项卡后会发生异常。

这是我的活动代码

＆＃13;

public class MutiTabActivity extends FragmentActivity {
	TabHost tabHost;
	private FragmentTabHost fragmentTabHost;
	private Button addButton;

	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main);
		addButton = (Button) findViewById(R.id.add_new_tab);
		addButton.setOnClickListener(new OnClickListener() {

			@Override
			public void onClick(View v) {
				addNewTab();
			}
		});

		fragmentTabHost = (FragmentTabHost) findViewById(R.id.main_tab_host);
		fragmentTabHost.setup(this, getSupportFragmentManager(), R.id.frame_layout);

		fragmentTabHost.getTabWidget().setDividerDrawable(android.R.color.white);

		fragmentTabHost.setOnTabChangedListener(new OnTabChangeListener() {

			@Override
			public void onTabChanged(String tabId) {
				onTabSelected();
			}
		});

		addNewTab();
		addNewTab();
		addNewTab();
		addNewTab();
	}

	OnClickListener closeTabListener = new OnClickListener() {

		@Override
		public void onClick(View v) {
			TabWidget tabWidget = fragmentTabHost.getTabWidget();
			tabWidget.removeViewAt(currentTabIndex);
		}
	};
	private int currentTabIndex;

	/*
	 * used to change the background color of selected tab and show close button
	 * on selected tab
	 */
	private void onTabSelected() {
		TabWidget tabWidget = fragmentTabHost.getTabWidget();
		int tabCount = tabWidget.getTabCount();
		for (int i = 0; i < tabCount; i++) {
			View childAt = tabWidget.getChildAt(i);
			View findViewById = childAt.findViewById(R.id.close_tab_textView1);
			if (findViewById != null) {
				findViewById.setVisibility(View.GONE);
				childAt.setBackgroundColor(Color.LTGRAY);
				findViewById.setOnClickListener(null);

				String currentTabTag = fragmentTabHost.getCurrentTabTag();

				String tag2 = (String) childAt.getTag();

				if (tag2 != null) {
					if (currentTabTag.equals(tag2)) {
						findViewById.setVisibility(View.VISIBLE);
						findViewById.setOnClickListener(closeTabListener);
						childAt.setBackgroundColor(Color.DKGRAY);
						currentTabIndex = i;
					}
				}
			}
		}
	}

	private int lastTabCount;

	private TabSpec getNewTab(String tag, String title) {

		TabSpec newTabSpec = fragmentTabHost.newTabSpec(tag);
		TabWidget tabWidget = fragmentTabHost.getTabWidget();
		View view2 = LayoutInflater.from(this).inflate(R.layout.tab_view, tabWidget, false);
		view2.setTag(tag);
		TextView name = (TextView) view2.findViewById(R.id.textView1);
		TextView closeBtn = (TextView) view2.findViewById(R.id.close_tab_textView1);
		closeBtn.setOnTouchListener(new OnTouchListener() {

			@Override
			public boolean onTouch(View v, MotionEvent event) {
				return false;
			}
		});
		name.setText(title);
		newTabSpec.setIndicator(view2);
		return newTabSpec;
	}

	/* add new tab in fragmentTabHost */
	private void addNewTab() {
		lastTabCount++;
		fragmentTabHost.addTab(getNewTab("Tag " + lastTabCount, "Tab " + lastTabCount), WebViewTab.class, null);
	}
}

＆＃13;

以下是日志

    05-11 03:48:27.652: E/AndroidRuntime(11073): FATAL EXCEPTION: main
05-11 03:48:27.652: E/AndroidRuntime(11073): java.lang.NullPointerException
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.widget.TabWidget.focusCurrentTab(TabWidget.java:461)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.widget.TabHost.setCurrentTab(TabHost.java:410)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:154)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:546)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.view.View.performClick(View.java:4240)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.view.View$PerformClick.run(View.java:17721)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.os.Handler.handleCallback(Handler.java:730)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.os.Handler.dispatchMessage(Handler.java:92)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.os.Looper.loop(Looper.java:137)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at android.app.ActivityThread.main(ActivityThread.java:5103)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at java.lang.reflect.Method.invokeNative(Native Method)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at java.lang.reflect.Method.invoke(Method.java:525)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553)
05-11 03:48:27.652: E/AndroidRuntime(11073):    at dalvik.system.NativeStart.main(Native Method)

我发现了here这样的问题，但解决方案提供的对我来说并不适用。

先谢谢，请帮帮我。

在fragmentTabHost中

0 个答案: