Question

我创建了一个对话框片段。当我按下子菜单项时，我需要让这个对话框进入我当前的活动。所以我创建并声明了AlertDialog.Builder构建;在我的活动开始之内。

public class Placed_Product_Details extends Activity {
String usrnme,name,proid;
AlertDialog.Builder builde;

其代码如下。

public Dialog onCreateDialog(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    builde = new AlertDialog.Builder(Placed_Product_Details.this);
    LayoutInflater inflater = Placed_Product_Details.this.getLayoutInflater();
      // Inflate and set the layout for the dialog
    // Pass null as the parent view because its going in the dialog layout
    builde.setView(inflater.inflate(R.layout.updateproductname, null))
    // Add action buttons
           .setPositiveButton("OK", new DialogInterface.OnClickListener() {
               @Override
               public void onClick(DialogInterface dialog, int id) {
                   // sign in the user ...
               }
           });

    return builde.create();

}

这是子菜单代码的一部分。

public boolean onOptionsItemSelected(MenuItem item) {
    // TODO Auto-generated method stub
    switch (item.getItemId()) {
    case R.id.delete:
    {

        //here i have the code for deleting from the database

        break;
    }
    case R.id.updateproductname:
    {

                //here I have created a dialog and called it here. The code 
                 //of the dialog is posted above
        AlertDialog ab=builde.create();
        ab.show();
        break;
    }
    default:
        break;
    }
    return super.onOptionsItemSelected(item);

}

这是我在项目的res / layout /文件夹中创建的对话框updateproductname.xml的布局。

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical" >

<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="45dp"
    android:layout_marginTop="30dp"
    android:text="Update Product Name"
    android:textAppearance="?android:attr/textAppearanceLarge" />

<EditText
    android:id="@+id/productnameedittext"
    android:layout_width="match_parent"
    android:layout_marginLeft="0dp"
    android:layout_marginTop="30dp"
    android:hint="Enter new product name here"
    android:layout_height="wrap_content"
    android:ems="10" >

    <requestFocus />
</EditText>

<Button
    android:id="@+id/productnamebutton"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_marginLeft="50dp"
    android:layout_marginTop="30dp"
    android:text="Change Product Name" />

</LinearLayout>

当我点击子菜单时，我的应用程序强制突然关闭。我不知道为什么？我将显示显示错误的logcat。这是因为我错误地创建了对话框片段。有人可以告诉我我的应用程序中的错误。

编辑：这是我的错误的完整日志..

02-17 10:50:23.267: D/AndroidRuntime(687): Shutting down VM
02-17 10:50:23.318: W/dalvikvm(687): threadid=1: thread exiting with uncaught exception (group=0x40015560)
 02-17 10:50:23.416: E/AndroidRuntime(687): FATAL EXCEPTION: main
02-17 10:50:23.416: E/AndroidRuntime(687): java.lang.NullPointerException
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.example.onlineauction.Placed_Product_Details.onOptionsItemSelected(Placed_Product_Details.java:188)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.app.Activity.onMenuItemSelected(Activity.java:2205)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.policy.impl.PhoneWindow.onMenuItemSelected(PhoneWindow.java:748)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.view.menu.MenuItemImpl.invoke(MenuItemImpl.java:143)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.view.menu.MenuBuilder.performItemAction(MenuBuilder.java:855)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.view.menu.MenuDialogHelper.onClick(MenuDialogHelper.java:137)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.app.AlertController$AlertParams$3.onItemClick(AlertController.java:873)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.widget.AdapterView.performItemClick(AdapterView.java:284)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.widget.ListView.performItemClick(ListView.java:3513)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.widget.AbsListView$PerformClick.run(AbsListView.java:1812)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.os.Handler.handleCallback(Handler.java:587)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.os.Handler.dispatchMessage(Handler.java:92)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.os.Looper.loop(Looper.java:123)
02-17 10:50:23.416: E/AndroidRuntime(687):  at android.app.ActivityThread.main(ActivityThread.java:3683)
02-17 10:50:23.416: E/AndroidRuntime(687):  at java.lang.reflect.Method.invokeNative(Native Method)
02-17 10:50:23.416: E/AndroidRuntime(687):  at java.lang.reflect.Method.invoke(Method.java:507)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-17 10:50:23.416: E/AndroidRuntime(687):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-17 10:50:23.416: E/AndroidRuntime(687):  at dalvik.system.NativeStart.main(Native Method)
02-17 10:50:27.746: I/Process(687): Sending signal. PID: 687 SIG: 9

第二次编辑：这是显示错误的第二个logcat。

02-17 12:07:11.577: E/AndroidRuntime(769): FATAL EXCEPTION: main
02-17 12:07:11.577: E/AndroidRuntime(769): java.lang.NullPointerException
02-17 12:07:11.577: E/AndroidRuntime(769):  at com.example.onlineauction.Placed_Product_Details$1.onClick(Placed_Product_Details.java:212)
02-17 12:07:11.577: E/AndroidRuntime(769):  at com.android.internal.app.AlertController$ButtonHandler.handleMessage(AlertController.java:159)
02-17 12:07:11.577: E/AndroidRuntime(769):  at android.os.Handler.dispatchMessage(Handler.java:99)
02-17 12:07:11.577: E/AndroidRuntime(769):  at android.os.Looper.loop(Looper.java:123)
02-17 12:07:11.577: E/AndroidRuntime(769):  at android.app.ActivityThread.main(ActivityThread.java:3683)
02-17 12:07:11.577: E/AndroidRuntime(769):  at java.lang.reflect.Method.invokeNative(Native Method)
02-17 12:07:11.577: E/AndroidRuntime(769):  at java.lang.reflect.Method.invoke(Method.java:507)
02-17 12:07:11.577: E/AndroidRuntime(769):  at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:839)
02-17 12:07:11.577: E/AndroidRuntime(769):  at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:597)
02-17 12:07:11.577: E/AndroidRuntime(769):  at dalvik.system.NativeStart.main(Native Method)
02-17 12:07:15.667: I/Process(769): Sending signal. PID: 769 SIG: 9

Answer 1

首先，变量builder未初始化，因为onCreateDialog()未被调用...

您可能认为自己正在覆盖onCreateDialog()的{{1}}方法，但实际上并非如此。

查看Activity

中onCreateDialog()的定义

Activity

仅供参考...这两种方法已被弃用。

但你写了

protected Dialog onCreateDialog(int);
protected Dialog onCreateDialog(int,Bundle);

不会覆盖protected Dialog onCreateDialog(Bundle);的任何方法...（使用Activity注释来了解您实际上是否覆盖）

您可以在不使用Override方法时删除Bundle参数。

onCreateDialog()

并在点击适当的public Dialog onCreateDialog() { // TODO Auto-generated method stub builde = new AlertDialog.Builder(Placed_Product_Details.this); LayoutInflater inflater = Placed_Product_Details.this .getLayoutInflater(); // Inflate and set the layout for the dialog // Pass null as the parent view because its going in the dialog layout builde.setView(inflater.inflate(R.layout.updateproductname, null)) // Add action buttons .setPositiveButton("OK", new DialogInterface.OnClickListener() { @Override public void onClick(DialogInterface dialog, int id) { // sign in the user ... } }); return builde.create(); }时调用此方法...

MenuItem

在android活动中创建子菜单项内的Dialog Fragment时出错

1 个答案: