使用XML的onClick当Android的对话框NoSuchMethodException错误 [英] Android Dialog NoSuchMethodException error when using XML onClick

问题描述

我是新来的Java和Android，和我的工作我的第一个测试应用程序。

I'm new to Java and Android, and I'm working on my first test app.

我已经取得了进展，但我阻止了对话。

I've progressed with it, but I'm blocked with a Dialog.

我秀从活动像这样的对话：

I show the dialog from the Activity like this:

//BuyActivity.java
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_shop);

    initialize_PR();
    display_PR();
    BuyDialog=new Dialog(this);
    BuyDialog.setContentView(R.layout.dialog_buy);

}
public void Action_ShowDialog_Buy(View view) {
    BuyDialog.show() ;
}

和被点击的活动触发Action_ShowDialog_Buy按钮时，可以正确所示的对话框。但在此之后，该对话本身有一个按钮：

And the dialog is correctly shown when the button of the Activity that triggers Action_ShowDialog_Buy is clicked. But after that, the Dialog itself has a button:

<!-- dialog_buy.xml -->
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent" >

<!-- Other stuff -->

<Button
    android:id="@+id/Button_Buy"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@+id/Some_Other_Stuff"
    android:layout_centerHorizontal="true"
    android:text="@string/button_buy"
    android:onClick="Action_ShowDialog_Buy" />

</RelativeLayout>

按钮的方法Action_ShowDialog_Buy上的活动实现的：

The button method Action_ShowDialog_Buy is implemented on the Activity:

public void Action_ShowDialog_Buy(View view) {
    BuyDialog.dismiss() ;
}

但是当我点击在对话框中的按钮我收到错误消息：

but when I click on the Button in the Dialog I receive the error:

java.lang.IllegalStateException: Could not find a method BuyActivity.Action_ShowDialog_Buy(View) in the activity class android.view.ContextThemeWrapper for onClick handler on view class android.widget.Button with id 'Button_Buy'

和如下：

Caused by: java.lang.NoSuchMethodException:BuyActivity.Action_ShowDialog_Buy

但你可以在上面看到，该方法上存在活动。

but as you can see above, the method exists on the Activity.

我想我明白这是某种类型的范围的问题，但我不设法了解它。请注意，我readed <一个href=\"http://stackoverflow.com/questions/4243704/using-onclick-attribute-in-layout-xml-causes-a-nosuchmethodexception-in-android\">Using在的onClick布局XML属性导致Android的对话框一个NoSuchMethodException但我需要去理解，而不仅仅是复制code。

I think I understand this is some kind of scope issue, but I do not manage to understand it. Please note that I have readed Using onClick attribute in layout xml causes a NoSuchMethodException in Android dialogs but I need to understand, not just to copy code.

非常感谢

推荐答案

感谢大家，试图帮助。

我已经成功通过从对话框派生的类，并使用它，用这个code到排序了这一点：

I've managed to sort this out by creating a class derived from Dialog and using it, using this code:

import android.app.Dialog;
import android.content.Context;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.widget.RelativeLayout;

public class BuyDialogClass extends Dialog
{

//Ensure this Dialog has a Context we can use
Context mContext ;

public BuyDialogClass(Context context) {
    super(context);
    mContext=context; //Store the Context as provided from caller
}

@Override
 protected void onCreate(final Bundle savedInstanceState)
 {
  super.onCreate(savedInstanceState);
  RelativeLayout ll=(RelativeLayout) LayoutInflater.from(mContext).inflate(R.layout.dialog_buy, null);
  setContentView(ll); 
 }

}

这让我打电话给那个对话框，这样的：

This allowed me to call the dialog as this:

public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_shop);

    initialize_PR();
    display_PR();
    BuyDialog=new BuyDialogClass(this);
    //The setContentView is not necessary here as we call it on the onCreate

    //We can NOT access Dialog widgets from here,
    //because the dialog has not yet been shown.

}
public void Action_ShowDialog_Buy(View view) {
    BuyDialog.show() ;

    //NOW, after showing the dialog, we can access its widgets
    jobject_SeekBar_buy= (SeekBar) BuyDialog.findViewById(R.id.SeekBar_Dialog_Buy) ;
    jobject_SeekBar_buy.setMax(PR_num_coins/currentPR_buy_price) ;
    jobject_SeekBar_buy.setOnSeekBarChangeListener(this);

}
public void Action_Buy_PR(View view) {
    BuyDialog.dismiss() ;
}

我设法做到这一点通过阅读<一href=\"http://stackoverflow.com/questions/4243704/using-onclick-attribute-in-layout-xml-causes-a-nosuchmethodexception-in-android\">Using在的onClick布局XML属性导致Android的对话框一个NoSuchMethodException ，但我还是不明白这个语境问题。

I managed to do this by reading Using onClick attribute in layout xml causes a NoSuchMethodException in Android dialogs but I still do not understand this Context issue.

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