我想从数据库中检索数据。它显示为display1.setOnClickListener(this);
错误请任何人提出一个解决方案给我。在android sqlite中检索数据造成麻烦
@Override
protected void onCreate(Bundle savedInstanceState) {
// TODO Auto-generated method stub
super.onCreate(savedInstanceState);
display1=(Button)findViewById(R.id.button1);
inputid=(EditText)findViewById(R.id.display);
display1.setOnClickListener(this);
}
public void onClick(View v) {
// TODO Auto-generated method stub
int id=Integer.parseInt(inputid.getText().toString());
DBAdapter dbadapter=new DBAdapter(this);
Cursor c=dbadapter.display(id);
Toast.makeText(this, "Name: " + c.getString(1) , Toast.LENGTH_LONG).show();
}
logcat的是
12-26 16:27:26.438:d/AndroidRuntime(31283):关闭VM 12-26 16:27:26.438:W/dalvikvm(31283):线程ID = 1:线程退出未捕获的异常(组= 0x40015560) 12-26 16:27:26.448:E/AndroidRuntime(31283):致命例外:主 12-26 16:27:26.448:E/AndroidRuntime(31283) :java.lang.RuntimeException:无法启动活动ComponentInfo {com.android.database/com.android.database.Display}:java.lang.NullPointerException 12-26 16:27:26.448:E/AndroidRuntime(31283):在android.app.ActivityThread.performLaunchActi vity(ActivityThread.java:1647) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1663) 12-26 16:27:26.448: E/AndroidRuntime(31283):at android.app.ActivityThread.access $ 1500(ActivityThread.java:117) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.app.ActivityThread $ H.handleMessage (ActivityThread.java:931) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.os.Handler.dispatchMessage(Handler.java:99) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.os.Looper.loop(Looper.java:123) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.app.ActivityThread.main(ActivityThread.java :3683) 12-26 16:27:26.448:E/AndroidRuntime(31283):at java.lang.reflect.Method.invokeNative(Native Method) 12-26 16:27:26.448:E/AndroidRuntime(31283):at java.lang.reflect.Method.invoke(Method.java:507) 12-26 16:27:26.448:E/AndroidRuntime(31283) :at com.android.internal.os.ZygoteInit $ MethodAndArgsCaller.run(ZygoteInit.java:839) 12-26 16:27:26.448:E/AndroidRuntime(31283):at com.android.internal.os.ZygoteInit。 main(ZygoteInit.java:597) 12-26 16:27:26.448:E/AndroidRuntime(31283):at dalvik.system.NativeStart.main(Native Method) 12-26 16:27:26.448:E/AndroidRuntime (31283):导致:java.lang.NullPointerException 12-26 16:27:26.448:E/AndroidRuntime(31283):在com.android.database.Display.onCreate(Display.java:23)*** *错误 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.app.Instrumentation.callActi vityOnCreate(Instrumentation.java:1047) 12-26 16:27:26.448:E/AndroidRuntime(31283):at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:1611) 12-26 16:27:26.448: E/AndroidRuntime(31283):... 11更多 12-26 16:27:28.448:I /进程(31283):发送信号。 PID:31283 SIG:9
粘贴错误日志的完整代码 – Pratik 2011-12-26 10:15:38
是的Pratik是正确的,在'display'方法中有什么,我们如何建议你一个解决方案,而不知道完整的代码与日志? – 2011-12-26 10:19:34