应用程序在仿真器上意外停止

我想要设计一个应用程序，它有4个按钮，每个按钮的值都是1到4，空格按钮。点击一个按钮，它会在textview中给出一个值。当在模拟器上运行时，它会给应用程序意外停止提供错误。 Java代码如下：应用程序在仿真器上意外停止

package com.android.tusway; 

import android.app.Activity; 
import android.os.Bundle; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.Button; 
import android.widget.EditText; 
import android.widget.TextView; 


public class TapkeysActivity extends Activity { 
/** Called when the activity is first created. */ 


private Button b1,b2,b3,b4,bspace; 
private String stringDb; 
private TextView tv; 


private void updateTextField() { 
    tv.setText(this.stringDb); 


} 


@Override 
    public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 

     setContentView(R.layout.main); 
     // adjusting key regarding window sizes 

     et = (EditText) findViewById(R.id.editText1); 

     b1 = (Button) findViewById(R.id.button1); 
     b2 = (Button) findViewById(R.id.button2); 
     b3 = (Button) findViewById(R.id.button3); 
     b4 = (Button) findViewById(R.id.button4); 
     bspace = (Button) findViewById(R.id.btspace); 

     tv = (TextView) findViewById(R.id.textView1); 

     b1.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       stringDb += "1"; 
       updateTextField(); 

      } 
     }); 


     b2.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       stringDb += "2"; 
       updateTextField(); 

      } 
     }); 

     b3.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       stringDb += "3"; 
       updateTextField(); 

      } 
     }); 

     b4.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       stringDb += "4"; 
       updateTextField(); 

      } 
     }); 

     bspace.setOnClickListener(new OnClickListener() { 

      @Override 
      public void onClick(View v) { 
       stringDb += " "; 
       updateTextField(); 

      } 
     }); 

} 
    }

main.xml中的布局

<?xml version="1.0" encoding="utf-8"?> 
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" 
android:layout_width="fill_parent" 
android:layout_height="fill_parent" 
> 
<EditText android:layout_height="wrap_content" android:layout_width="match_parent"  android:id="@+id/editText1"> 
    <requestFocus></requestFocus> 
</EditText> 
<TextView android:id="@+id/textView1" android:layout_width="fill_parent" android:layout_height="wrap_content"></TextView> 
<Button android:id="@+id/button1" android:layout_height="wrap_content" android:layout_width="100dp" android:text="1"></Button> 
<Button android:text="2" android:id="@+id/button2" android:layout_height="wrap_content" android:layout_width="97dp"></Button> 
<Button android:text="3" android:id="@+id/button3" android:layout_height="wrap_content" android:layout_width="96dp"></Button> 
<Button android:text="4" android:id="@+id/button4" android:layout_height="wrap_content" android:layout_width="97dp"></Button> 
<Button android:id="@+id/btspace" android:layout_height="wrap_content" android:text="Space" android:layout_width="match_parent"></Button> 
</LinearLayout>

的logcat：

01-17 00:23:50.069: ERROR/AndroidRuntime(1337): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.tusway/com.android.tusway.TapkeysActivity}: java.lang.NullPointerException 
01-17 00:23:50.069: ERROR/AndroidRuntime(1337):  at com.android.tusway.TapkeysActivity.onCreate(TapkeysActivity.java:86)

的logcat：

01-17 00:12:31.319: DEBUG/PackageManager(54): Scanning package com.android.tusway 
01-17 00:12:31.389: INFO/PackageManager(54): /data/app/com.android.tusway-1.apk changed; unpacking 
01-17 00:12:31.469: DEBUG/installd(34): DexInv: --- BEGIN '/data/app/com.android.tusway-1.apk' --- 
01-17 00:12:32.820: DEBUG/installd(34): DexInv: --- END '/data/app/com.android.tusway-1.apk' (success) --- 
01-17 00:12:32.829: DEBUG/PackageManager(54): Activities: com.android.tusway.TapkeysActivity 
01-17 00:12:32.849: INFO/ActivityManager(54): Force stopping package com.android.tusway uid=10043 
01-17 00:12:33.639: INFO/installd(34): move /data/dalvik-cache/[email protected]@[email protected] -> /data/dalvik-cache/[email protected]@[email protected] 
01-17 00:12:33.659: DEBUG/PackageManager(54): New package installed in /data/app/com.android.tusway-1.apk 
01-17 00:12:49.059: INFO/ActivityManager(54): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.android.tusway/.TapkeysActivity } 
01-17 00:12:50.719: INFO/ActivityManager(54): Start proc com.android.tusway for activity com.android.tusway/.TapkeysActivity: pid=1307 uid=10043 gids={} 
01-17 00:12:53.663: ERROR/AndroidRuntime(1307): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.tusway/com.android.tusway.TapkeysActivity}: java.lang.NullPointerException 
01-17 00:12:53.663: ERROR/AndroidRuntime(1307):  at com.android.tusway.TapkeysActivity.onCreate(TapkeysActivity.java:86) 
01-17 00:12:53.769: WARN/ActivityManager(54): Force finishing activity com.android.tusway/.TapkeysActivity 
01-17 00:12:54.629: WARN/ActivityManager(54): Activity pause timeout for HistoryRecord{44f94e30 com.android.tusway/.TapkeysActivity} 
01-17 00:13:04.169: INFO/ActivityManager(54): Process com.android.tusway (pid 1307) has died. 
01-17 00:13:08.790: WARN/ActivityManager(54): Activity destroy timeout for HistoryRecord{44f94e30 com.android.tusway/.TapkeysActivity} 
01-17 00:23:18.783: INFO/PackageManager(54): Removing non-system package:com.android.tusway 
01-17 00:23:18.791: INFO/ActivityManager(54): Force stopping package com.android.tusway uid=10043 
01-17 00:23:20.010: DEBUG/PackageManager(54): Scanning package com.android.tusway 
01-17 00:23:20.060: INFO/PackageManager(54): Package com.android.tusway codePath changed from /data/app/com.android.tusway-1.apk to /data/app/com.android.tusway-2.apk; Retaining data and using new 
01-17 00:23:20.118: INFO/PackageManager(54): /data/app/com.android.tusway-2.apk changed; unpacking 
01-17 00:23:20.200: DEBUG/installd(34): DexInv: --- BEGIN '/data/app/com.android.tusway-2.apk' --- 
01-17 00:23:21.969: DEBUG/installd(34): DexInv: --- END '/data/app/com.android.tusway-2.apk' (success) --- 
01-17 00:23:22.000: INFO/ActivityManager(54): Force stopping package com.android.tusway uid=10043 
01-17 00:23:22.009: WARN/PackageManager(54): Code path for pkg : com.android.tusway changing from /data/app/com.android.tusway-1.apk to /data/app/com.android.tusway-2.apk 
01-17 00:23:22.119: WARN/PackageManager(54): Resource path for pkg : com.android.tusway changing from /data/app/com.android.tusway-1.apk to /data/app/com.android.tusway-2.apk 
01-17 00:23:22.199: DEBUG/PackageManager(54): Activities: com.android.tusway.TapkeysActivity 
01-17 00:23:23.219: INFO/installd(34): move /data/dalvik-cache/[email protected]@[email protected] -> /data/dalvik-cache/[email protected]@[email protected] 
01-17 00:23:23.219: DEBUG/PackageManager(54): New package installed in /data/app/com.android.tusway-2.apk 
01-17 00:23:23.219: INFO/ActivityManager(54): Force stopping package com.android.tusway uid=10043 
01-17 00:23:29.479: INFO/installd(34): unlink /data/dalvik-cache/[email protected]@[email protected] 
01-17 00:23:44.229: INFO/ActivityManager(54): Starting activity: Intent { act=android.intent.action.MAIN cat=[android.intent.category.LAUNCHER] flg=0x10000000 cmp=com.android.tusway/.TapkeysActivity } 
01-17 00:23:46.030: INFO/ActivityManager(54): Start proc com.android.tusway for activity com.android.tusway/.TapkeysActivity: pid=1337 uid=10043 gids={} 
01-17 00:23:50.069: ERROR/AndroidRuntime(1337): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.android.tusway/com.android.tusway.TapkeysActivity}: java.lang.NullPointerException 
01-17 00:23:50.069: ERROR/AndroidRuntime(1337):  at com.android.tusway.TapkeysActivity.onCreate(TapkeysActivity.java:86) 
01-17 00:23:50.179: WARN/ActivityManager(54): Force finishing activity com.android.tusway/.TapkeysActivity 
01-17 00:23:51.263: WARN/ActivityManager(54): Activity pause timeout for HistoryRecord{44fc8bf8 com.android.tusway/.TapkeysActivity} 
01-17 00:24:06.806: WARN/ActivityManager(54): Activity destroy timeout for HistoryRecord{44fc8bf8 com.android.tusway/.TapkeysActivity} 
01-17 00:28:52.774: INFO/ActivityManager(54): Process com.android.tusway (pid 1337) has died.

来源

2013-01-16 TUSWAY

确保在main.xml布局中有一个带有'btspace' id的按钮 –

btspace在代码中声明。我已经提到main.xml代码 – TUSWAY

@TUSWAY将您的完整logcat文件放在这里。 –

你没有开始你的stringDB ，你可以先把它放在0

来源

2013-01-16 19:29:19 Goo

Arf，我迟到了...... ^^ 它是一个字符串......所以用“”开头 – Goo

应用程序在仿真器上意外停止

回答

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