GridView 的 onCreate() 方法永远不会被调用

Question

我有一个 gridView，如下所示：

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/rl_drag_and_drop_app"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
>
<SlidingDrawer
    android:id="@+id/bottom"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:layout_centerVertical="true"
    android:orientation="horizontal"
    android:layout_marginTop="200dp"
    android:content="@+id/content"
    android:handle="@+id/handle" >

    <Button
        android:id="@+id/handle"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:background="@drawable/arrow" />

    <LinearLayout
        android:id="@+id/content"
        android:layout_width="match_parent"
        android:layout_height="match_parent" 
        android:orientation="vertical"
        android:background="#00FF00">

            <!-- Editext for Search -->
<EditText android:id="@+id/inputSearch"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:hint="@string/Search_applications"
    android:inputType="textVisiblePassword"/>

<ListView
    android:id="@+id/lvApps"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"       
 />
    </LinearLayout>
 </SlidingDrawer>

        <Button
        android:id="@+id/btnLinkToPersonalize"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:layout_marginTop="10dip"
        android:background="@null"
        android:text="@string/Personalize"
        android:textColor="#21dbd4"
        android:textStyle="bold" />

<GridView 
android:id="@+id/GRIDVIEW1"
android:layout_width="fill_parent"
android:layout_height="wrap_content"
android:layout_marginTop="30dip"
android:numColumns="auto_fit"
android:columnWidth="60dp"
android:horizontalSpacing="10dp"
android:verticalSpacing="10dp"
android:gravity="center"
android:stretchMode="columnWidth"
 >  

</GridView>

 <ImageView
    android:id="@+id/trash_can"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentBottom="true"
    android:layout_centerHorizontal="true"
    android:contentDescription="@string/trashcanDescription_Delete"
    android:padding="40dip"
    android:src="@drawable/trashcan"
    android:visibility="gone" >
</ImageView>

</RelativeLayout>

然后将我的 gridView 适配器放在一个单独的类中，如下所示：

package com.example.awesomefilebuilderwidget;
IMPORTS
public class GridView extends Activity { // implements OnItemLongClickListener, OnDragListener{

ArrayList<Integer> drawables = new ArrayList<Integer>();

private BaseAdapter adapter;
private int draggedIndex = -1;
android.widget.GridView gridView = (android.widget.GridView) findViewById(R.id.GRIDVIEW1);

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.drag_and_drop_app);
    Log.d("GridView", "onCreate called");
    drawables = new ArrayList<Integer>();
    drawables.add(R.drawable.pattern1);
    drawables.add(R.drawable.pattern2);
    // gridView.setOnItemLongClickListener(this);
    gridView.setAdapter(adapter = new BaseAdapter() {

        @Override
        // Get a View that displays the data at the specified position in
        // the data set.
        public View getView(int position, View convertView,
                ViewGroup gridView) {
            // try to reuse the views.
            ImageView view = (ImageView) convertView;
            // if convert view is null then create a new instance else reuse
            // it
            if (view == null) {
                view = new ImageView(GridView.this);
            }
            /*Bundle extras = getIntent().getExtras();
            byte[] byteArray = extras.getByteArray("picture");

            Bitmap default_b = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);

            view.setImageBitmap(default_b);*/
            view.setImageResource(drawables.get(position));
            view.setScaleType(ImageView.ScaleType.CENTER_CROP);
            view.setLayoutParams(new android.widget.GridView.LayoutParams(70, 70));
            view.setTag(String.valueOf(position));
            return view;
        }

        @Override
        // Get the row id associated with the specified position in the
        // list.
        public long getItemId(int position) {
            return position;
        }

        @Override
        // Get the data item associated with the specified position in the
        // data set.
        public Object getItem(int position) {
            return drawables.get(position);
        }

        @Override
        // How many items are in the data set represented by this Adapter.
        public int getCount() {
            return drawables.size();
        }
    });
}

/*@Override
public boolean onItemLongClick(AdapterView<?> gridView, View view,
        int position, long row) {
    ClipData.Item item = new ClipData.Item((String) view.getTag());
    ClipData clipData = new ClipData((CharSequence) view.getTag(),
            new String[] { ClipDescription.MIMETYPE_TEXT_PLAIN }, item);
    view.startDrag(clipData, new View.DragShadowBuilder(view), null, 0);
    View trashCan = findViewById(R.id.trash_can);
    trashCan.setVisibility(View.VISIBLE);
    trashCan.setOnDragListener(GridView.this);
    trashCan.setOnDragListener(GridView.this);
    draggedIndex = position;
    return true;
}

@Override
public boolean onDrag(View view, DragEvent dragEvent) {
    switch (dragEvent.getAction()) {
    case DragEvent.ACTION_DRAG_STARTED:
        // Drag has started
        // If called for trash resize the view and return true
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
            return true;
        } else // else check the mime type and set the view visibility
        if (dragEvent.getClipDescription().hasMimeType(
                ClipDescription.MIMETYPE_TEXT_PLAIN)) {
            view.setVisibility(View.GONE);
            return true;

        } else {
            return false;
        }
    case DragEvent.ACTION_DRAG_ENTERED:
        // Drag has entered view bounds
        // If called for trash can then scale it.
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.5f);
            view.animate().scaleY(1.5f);
        }
        return true;
    case DragEvent.ACTION_DRAG_EXITED:
        // Drag exited view bounds
        // If called for trash can then reset it.
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
        }
        view.invalidate();
        return true;
    case DragEvent.ACTION_DRAG_LOCATION:
        // Ignore this event
        return true;
    case DragEvent.ACTION_DROP:
        // Dropped inside view bounds
        // If called for trash can then delete the item and reload the grid
        // view
        if (view.getId() == R.id.trash_can) {
            drawables.remove(draggedIndex);
            draggedIndex = -1;
        }
        adapter.notifyDataSetChanged();
    case DragEvent.ACTION_DRAG_ENDED:
        // Hide the trash can
        new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                findViewById(R.id.trash_can).setVisibility(View.GONE);
            }
        }, 1000l);
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
        } else {
            view.setVisibility(View.VISIBLE);
        }
        // remove drag listeners
        view.setOnDragListener(null);
        return true;

    }
    return false;
}*/



}

这个问题是我的 gridView 的 onCreate() 方法从未被调用过，因此我的 gridView 根本没有出现。我不知道为什么。我在 Manifest 中的所有编码都是正确的（据我所知），并且我尝试在我的 xml 文件上执行不同的高度和宽度以使我的 gridView 出现。无论我尝试了什么，我的 gridView 都不会显示。

顺便说一下，这是我的清单：

    <manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="com.example.awesomefilebuilderwidget"
android:versionCode="1"
android:versionName="1.0" >

<uses-sdk
android:minSdkVersion="8"
android:targetSdkVersion="18" />

<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />

<application
android:allowBackup="true"
android:icon="@drawable/ic_launcher"
android:label="@string/app_name"
android:theme="@style/AppTheme" >

<receiver android:name="com.example.awesomefilebuilderwidget.AFBWidget" android:label="@string/app_name">
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_UPDATE"/>
</intent-filter>

<meta-data android:name="android.appwidget.provider"
android:resource="@xml/widget_stuff"/>

</receiver>

<activity android:name="com.example.awesomefilebuilderwidget.WidgetConfig" android:label="@string/app_name">
<intent-filter>
<action android:name="android.appwidget.action.APPWIDGET_CONFIGURE"/>

</intent-filter> 

</activity>   

<activity android:name="com.example.awesomefilebuilderwidget.Drag_and_Drop_App" android:label="@string/app_name" android:windowSoftInputMode="stateHidden" android:screenOrientation="portrait"></activity>
<activity android:name="com.example.awesomefilebuilderwidget.AppInfoAdapter" android:label="@string/app_name" ></activity>
<activity android:name="com.example.awesomefilebuilderwidget.Feedback" android:label="@string/app_name" ></activity>
<activity android:name="com.example.awesomefilebuilderwidget.SendMessageActivity" android:label="@string/app_name" ></activity>
<activity android:name="com.example.awesomefilebuilderwidget.Utilities" android:label="@string/app_name" ></activity>
<activity android:name="com.example.awesomefilebuilderwidget.Personalize" android:label="@string/app_name" ></activity>
<activity android:name="com.example.awesomefilebuilderwidget.GridView" android:label="@string/app_name"></activity>
<activity android:name="com.example.awesomefilebuilderwidget.SwipeDetector"  android:label="@string/app_name"></activity>

</application>

</manifest> 

请帮忙！可能是什么问题？

编辑后添加：

这是我更新的类，因此我的适配器在它自己的类中...... GridView.java：

  package com.example.awesomefilebuilderwidget;

import java.util.ArrayList;

import android.app.Activity;
import android.os.Bundle;
import android.util.Log;
import android.widget.BaseAdapter;

public class GridView extends Activity {// implements OnItemLongClickListener, OnDragListener{

private int draggedIndex = -1;
private BaseAdapter adapter;
ArrayList<Integer> drawables = new ArrayList<Integer>();

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.drag_and_drop_app);
    Log.d("GridView", "onCreate called");
    drawables.add(R.drawable.pattern1);
    drawables.add(R.drawable.pattern2);

    android.widget.GridView gridView = (android.widget.GridView) findViewById(R.id.GRIDVIEW1);

    // Instance of Adapter Class
    gridView.setAdapter(new GridViewAdapter(this));
   // gridView.setOnItemLongClickListener(this);
}

/*  @Override
public boolean onItemLongClick(AdapterView<?> gridView, View view,
        int position, long row) {
    ClipData.Item item = new ClipData.Item((String) view.getTag());
    ClipData clipData = new ClipData((CharSequence) view.getTag(),
            new String[] { ClipDescription.MIMETYPE_TEXT_PLAIN }, item);
    view.startDrag(clipData, new View.DragShadowBuilder(view), null, 0);
    View trashCan = findViewById(R.id.trash_can);
    trashCan.setVisibility(View.VISIBLE);
    trashCan.setOnDragListener(GridView.this);
    trashCan.setOnDragListener(GridView.this);
    draggedIndex = position;
    return true;
}

@Override
public boolean onDrag(View view, DragEvent dragEvent) {
    switch (dragEvent.getAction()) {
    case DragEvent.ACTION_DRAG_STARTED:
        // Drag has started
        // If called for trash resize the view and return true
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
            return true;
        } else // else check the mime type and set the view visibility
        if (dragEvent.getClipDescription().hasMimeType(
                ClipDescription.MIMETYPE_TEXT_PLAIN)) {
            view.setVisibility(View.GONE);
            return true;

        } else {
            return false;
        }
    case DragEvent.ACTION_DRAG_ENTERED:
        // Drag has entered view bounds
        // If called for trash can then scale it.
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.5f);
            view.animate().scaleY(1.5f);
        }
        return true;
    case DragEvent.ACTION_DRAG_EXITED:
        // Drag exited view bounds
        // If called for trash can then reset it.
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
        }
        view.invalidate();
        return true;
    case DragEvent.ACTION_DRAG_LOCATION:
        // Ignore this event
        return true;
    case DragEvent.ACTION_DROP:
        // Dropped inside view bounds
        // If called for trash can then delete the item and reload the grid
        // view
        if (view.getId() == R.id.trash_can) {
            drawables.remove(draggedIndex);
            draggedIndex = -1;
        }
        adapter.notifyDataSetChanged();
    case DragEvent.ACTION_DRAG_ENDED:
        // Hide the trash can
        new Handler().postDelayed(new Runnable() {

            @Override
            public void run() {
                findViewById(R.id.trash_can).setVisibility(View.GONE);
            }
        }, 1000l);
        if (view.getId() == R.id.trash_can) {
            view.animate().scaleX(1.0f);
            view.animate().scaleY(1.0f);
        } else {
            view.setVisibility(View.VISIBLE);
        }
        // remove drag listeners
        view.setOnDragListener(null);
        return true;

    }
    return false;
}
*/

}

GridViewAdapter.java：

package com.example.awesomefilebuilderwidget;

import java.util.ArrayList;

import android.content.Context;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;

public class GridViewAdapter extends BaseAdapter {
private Context mContext;

// Keep all Images in array list
public ArrayList<Integer> drawables = new ArrayList<Integer>();

// Constructor
public GridViewAdapter(Context c){
    mContext = c;
}

@Override
// How many items are in the data set represented by this Adapter
public int getCount() {
    return drawables.size();
}

@Override
// Get the data item associated with the specified position in the
// data set
public Object getItem(int position) {
    return drawables.get(position);
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // Try to reuse the views
    ImageView view = (ImageView) convertView;
    // if convert view is null then create a new instance else reuse it
    if (view == null) {
        view = new ImageView(mContext);
    }
    /*Bundle extras = getIntent().getExtras();
      byte[] byteArray = extras.getByteArray("picture");
      Bitmap default_b = BitmapFactory.decodeByteArray(byteArray, 0, byteArray.length);
      view.setImageBitmap(default_b);*/
    view.setImageResource(drawables.get(position));
    view.setScaleType(ImageView.ScaleType.CENTER_CROP);
    view.setLayoutParams(new android.widget.GridView.LayoutParams(70, 70));
    view.setTag(String.valueOf(position));
    return view;
}

}

然后我也将此活动添加到我的清单中：

<activity android:name="com.example.awesomefilebuilderwidget.GridView" android:label="@string/app_name" ></activity>

请注意，我的清单中没有 GridViewAdapter 作为活动

Answer 1

显然，您正在为适配器创建一个单独的 Activity 作为“容器”。情况不妙。只需将适配器本身变成一个单独的类。并非 Android 中的每个类都必须是 Activity！