Android - 當添加/刪除標籤錯誤

Question

我想開發一個代碼，當我喜歡在添加按鈕時它會添加標籤，並且有刪除按鈕來刪除標籤..但它工作正常爲3〜4倍，但它引發錯誤後...

和登錄貓是這樣的： -

02-28 16:33:37.832: E/AndroidRuntime(7830): FATAL EXCEPTION: main 
02-28 16:33:37.832: E/AndroidRuntime(7830): java.lang.NullPointerException 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.widget.TabWidget.focusCurrentTab(TabWidget.java:461) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.widget.TabHost.setCurrentTab(TabHost.java:410) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.widget.TabHost$2.onTabSelectionChanged(TabHost.java:154) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.widget.TabWidget$TabClickListener.onClick(TabWidget.java:546) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.view.View.performClick(View.java:4223) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.view.View$PerformClick.run(View.java:17487) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.os.Handler.handleCallback(Handler.java:800) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.os.Handler.dispatchMessage(Handler.java:100) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.os.Looper.loop(Looper.java:194) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at android.app.ActivityThread.main(ActivityThread.java:5371) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at java.lang.reflect.Method.invokeNative(Native Method) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at java.lang.reflect.Method.invoke(Method.java:525) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:833) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600) 
02-28 16:33:37.832: E/AndroidRuntime(7830):  at dalvik.system.NativeStart.main(Native Method) 

和

MainActivity.java

package com.example.sampletab; 

import android.app.TabActivity; 
import android.content.Intent; 
import android.graphics.Color; 
import android.os.Bundle; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.widget.Button; 
import android.widget.TabHost; 
import android.widget.TabHost.OnTabChangeListener; 
import android.widget.TabHost.TabSpec; 

@SuppressWarnings("deprecation") 
public class MainActivity extends TabActivity { 
    private static int tabIndex = 0; 
    private TabHost tabHost; 

    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 
     tabHost = getTabHost(); 

     tabHost.setOnTabChangedListener(new OnTabChangeListener() { 

      @Override 
      public void onTabChanged(String tabId) { 

       // set the First Tab as selected Tab. 
       setSelectedTabColor(); 
       // setTabColor(tabHost); 
      } 
     }); 
     // setTabColor(tabHost); 

     addTabs(); 
     delTabs(); 

     ((Button) findViewById(R.id.add_tab)) 
       .setOnClickListener(new View.OnClickListener() { 

        @Override 
        public void onClick(View v) { 
         // TODO Auto-generated method stub 
         tabIndex++; 
         addTabs(); 
        } 
       }); 
     ((Button) findViewById(R.id.del_tab)) 
       .setOnClickListener(new View.OnClickListener() { 

        @Override 
        public void onClick(View v) { 
         // TODO Auto-generated method stub 
         delTabs(); 
        } 
       }); 
    } 

    protected void setSelectedTabColor() { 
     // TODO Auto-generated method stub 
     for (int i = 0; i < tabHost.getTabWidget().getChildCount(); i++) { 
      tabHost.getTabWidget().getChildAt(i) 
        .setBackgroundColor(Color.LTGRAY); 
     } 
     tabHost.getTabWidget().getChildAt(tabHost.getCurrentTab()) 
       .setBackgroundColor(Color.RED); 
    } 

    private void delTabs() { 
     tabHost.getTabWidget().removeView(
       tabHost.getTabWidget().getChildTabViewAt(
         tabHost.getCurrentTab())); 

    } 
    private void addTabs() { 
     // TODO Auto-generated method stub 
     LayoutInflater layoutInflater = LayoutInflater.from(MainActivity.this); 
     Button tabBtn = (Button) layoutInflater.inflate(R.layout.tab_event, 
       null); 
     tabBtn.setText("Tabs" + tabIndex); 
     Intent tabintent = new Intent(MainActivity.this, BlankActivity.class); 
     setupTab(tabBtn, tabintent, "Tab" + tabIndex); 
    } 

    private void setupTab(View tabBtn, Intent setIntent, String tag) { 
     // TODO Auto-generated method stub 
     TabSpec setContent = tabHost.newTabSpec(tag).setIndicator(tabBtn) 
       .setContent(setIntent); 
     tabHost.addTab(setContent); 
    } 
} 

Answer 1

在向TabHost添加標籤之前，您需要設置可繪製的分隔線。

所以下面一行：

tabHost.getTabWidget().setDividerDrawable(R.color.light); 

應該上升。你可以直接打電話後：

TabHost tabHost = getTabHost();