下面是个例外：

 了java.lang.RuntimeException：无法启动活动ComponentInfo {spb.bridges / spb.bridges.Bridges}：android.database.sqlite.SQLiteException：无法打开数据库文件在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2663）在android.app.ActivityThread.handleLaunchActivity（ActivityThread.java:2679）在android.app.ActivityThread.access $ 2300（ActivityThread.java:125）在android.app.ActivityThread $ H.handleMessage（ActivityThread.java:2033）在android.os.Handler.dispatchMessage（Handler.java:99）在android.os.Looper.loop（Looper.java:123）在android.app.ActivityThread.main（ActivityThread.java:4627）在java.lang.reflect.Method.invokeNative（本机方法）在java.lang.reflect.Method.invoke（Method.java:521）在com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run（ZygoteInit.java:858）在com.android.internal.os.ZygoteInit.main（ZygoteInit.java:616）在dalvik.system.NativeStart.main（本机方法）android.database.sqlite.SQLiteException：引起无法打开数据库文件在android.database.sqlite.SQLiteDatabase.dbopen（本机方法）在android.database.sqlite.SQLiteDatabase＆LT;＆初始化GT;（SQLiteDatabase.java:1921）在android.database.sqlite.SQLiteDatabase.openDatabase（SQLiteDatabase.java:883）在android.database.sqlite.SQLiteDatabase.openOrCreateDatabase（SQLiteDatabase.java:960）在android.database.sqlite.SQLiteDatabase.openOrCreateDatabase（SQLiteDatabase.java:953）在android.app.ContextImpl.openOrCreateDatabase（ContextImpl.java:602）在android.content.ContextWrapper.openOrCreateDatabase（ContextWrapper.java:203）在android.database.sqlite.SQLiteOpenHelper.getWritableDatabase（SQLiteOpenHelper.java:98）在spb.bridges.DbAdapter.open（DbAdapter.java:172）在spb.bridges.Bridges.onCreate（Bridges.java:90）在android.app.Instrumentation.callActivityOnCreate（Instrumentation.java:1049）在android.app.ActivityThread.performLaunchActivity（ActivityThread.java:2627） 

和这里的code DbAdapter.open ：

 公共DbAdapter的open（）抛出的SQLException {    mDbHelper =新DatabaseHelper（mCtx）;    MDB = mDbHelper.getWritableDatabase（）;    返回此;} 

Bridges.onCreate ：

  @覆盖公共无效的onCreate（捆绑savedInstanceState）{    super.onCreate（savedInstanceState）;    的setContentView（R.layout.bridges_list）;    mDbHelper =新DbAdapter（本）;    mDbHelper.open（）; 

解决方案

看起来你上下文不充分，当您打开您的数据库初始化。

在你的 Bridges.onCreate 方法，你叫 super.onCreate ？ 的setContentView 之前的任何其他操作？

Here is the exception:

java.lang.RuntimeException: Unable to start activity ComponentInfo{spb.bridges/spb.bridges.Bridges}: android.database.sqlite.SQLiteException: unable to open database file
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:858)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:616)
at dalvik.system.NativeStart.main(Native Method)
Caused by: android.database.sqlite.SQLiteException: unable to open database file
at android.database.sqlite.SQLiteDatabase.dbopen(Native Method)
at android.database.sqlite.SQLiteDatabase.<init>(SQLiteDatabase.java:1921)
at android.database.sqlite.SQLiteDatabase.openDatabase(SQLiteDatabase.java:883)
at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:960)
at android.database.sqlite.SQLiteDatabase.openOrCreateDatabase(SQLiteDatabase.java:953)
at android.app.ContextImpl.openOrCreateDatabase(ContextImpl.java:602)
at android.content.ContextWrapper.openOrCreateDatabase(ContextWrapper.java:203)
at android.database.sqlite.SQLiteOpenHelper.getWritableDatabase(SQLiteOpenHelper.java:98)
at spb.bridges.DbAdapter.open(DbAdapter.java:172)
at spb.bridges.Bridges.onCreate(Bridges.java:90)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1049)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)

and here is the code of DbAdapter.open:

public DbAdapter open() throws SQLException {
    mDbHelper = new DatabaseHelper(mCtx);
    mDb = mDbHelper.getWritableDatabase();
    return this;
}

Bridges.onCreate:

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

    setContentView(R.layout.bridges_list);
    mDbHelper = new DbAdapter(this);
    mDbHelper.open();

It looks like you context is not fully initialized when you open your database.

In your Bridges.onCreate method, do you call super.onCreate? setContentView before any other operations?