我有基于这个例子的无限画廊：
http://blog.blundell-apps.com/infinite-scrolling-gallery/，一切正常：
正是我想将文本应用到每个图像并能够自定义文本，如图所示，并且每个图像的文本都比其他图像不同，但仍然无法通过无限画廊成功做到这一点
我尝试使用以下代码，但 在运行应用程序时它给了我FORCE CLOSE ，
（也许我写了错误的代码，但我仍在学习 Java 和 Android 开发的初学者）。
请任何帮助和建议将不胜感激
多谢。
我的代码：
GALLERY_ITEM
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/LinearLayout01"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="vertical"
android:gravity="center_horizontal">
<ImageView
android:id="@+id/image"
android:layout_height="300dp"
android:layout_width="fill_parent" />
<TextView
android:text="TextView"
android:id="@+id/textView1"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:textColor="#B22222"
android:textSize="20dp"
android:gravity="center"
android:layout_margin="30dp"
android:layout_below="@+id/image" />
然后在 InfiniteScrollingGalleryActivity.java 中更改如下：
public class InfiniteScrollingGalleryActivity extends Activity {
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Set the layout to use
setContentView(R.layout.main);
InfiniteGallery galleryOne = (InfiniteGallery) findViewById(R.id.galleryOne);
galleryOne.setAdapter(new InfiniteGalleryAdapter(this));
} }
然后更改 InfiniteGalleryResourceAdapter.java 如下：
public class InfiniteGalleryAdapter extends BaseAdapter {
/** The width of each child image */
private static final int G_ITEM_WIDTH = 360;
/** The height of each child image */
private static final int G_ITEM_HEIGHT = 240;
/** The context your gallery is running in (usually the activity) */
private Context mContext;
private int imageWidth;
private int imageHeight;
private int[] imageIds;
public InfiniteGalleryAdapter(Context c, int[] imageIds) {
this.mContext = c;
this.imageIds = imageIds; }
public int getCount() {
return Integer.MAX_VALUE; }
public Object getItem(int position) {
return position; }
public long getItemId(int position) {
return position; }
private Activity activity;
private LayoutInflater inflater=null;
public InfiniteGalleryAdapter(Activity a) {
final int[] imageIds;
activity = a;
inflater = (LayoutInflater)activity.getSystemService
Context.LAYOUT_INFLATER_SERVICE); }
public class ViewHolder{
public TextView text;
public ImageView image; }
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = getImageView();
try {
int itemPos = (position % imageIds.length);
i.setImageResource(imageIds[itemPos]);
((BitmapDrawable) i.getDrawable()).setAntiAlias(true); }
catch (OutOfMemoryError e) {
Log.e("InfiniteGalleryResourceAdapter", "Out of memory creating imageview.
Using empty view.", e); }
View vi=convertView;
ViewHolder holder;
if(convertView==null){
vi = inflater.inflate(R.layout.gallery_items, null);
holder=new ViewHolder();
holder.text=(TextView)vi.findViewById(R.id.textView1);
holder.image=(ImageView)vi.findViewById(R.id.image);
vi.setTag(holder); }
else
holder=(ViewHolder)vi.getTag();
holder.text.setText(name[position]);
final int stub_id=images[position];
holder.image.setImageResource(stub_id);
return vi; }
private int[] images = {
R.drawable.one_1, R.drawable.one_4,
R.drawable.one_2, R.drawable.one_5,
R.drawable.one_3 };
private String[] name = {
"this is my car", "i love this",
"please hekp me", "im in park",
" This is nice place to visit.", };
private ImageView getImageView() {
setImageDimensions();
ImageView i = new ImageView(mContext);
i.setLayoutParams(new Gallery.LayoutParams(imageWidth, imageHeight));
i.setScaleType(ScaleType.CENTER_INSIDE); return i; }
private void setImageDimensions() {
if (imageWidth == 0 || imageHeight == 0) {
imageWidth = AndroidUtils.convertToPix(mContext, G_ITEM_WIDTH);
imageHeight = AndroidUtils.convertToPix(mContext,G_ITEM_HEIGHT);
} }
}
这是 logcat 错误：
04-10 02:25:13.057: E/AndroidRuntime(12302): FATAL EXCEPTION: main
04-10 02:25:13.057: E/AndroidRuntime(12302): java.lang.NullPointerException
04-10 02:25:13.057: E/AndroidRuntime(12302):
at com.infinite.test.AndroidUtils.convertToPix(AndroidUtils.java:11)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at com.infinite.test.InfiniteGalleryAdapter.setImageDimensions
(InfiniteGalleryAdapter.java:131)
4-10 02:25:13.057: E/AndroidRuntime(12302):
at com.infinite.test.InfiniteGalleryAdapter.getImageView
(InfiniteGalleryAdapter.java:117)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at com.infinite.test.InfiniteGalleryAdapter.getView(InfiniteGalleryAdapter.java:66)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:192)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.View.measure( View.java:8366)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1017)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.LinearLayout.measureVertical(LinearLayout.java:386)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.View.measure(View.java:8366)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.ViewGroup.measureChildWithMargins(viewGroup.java:3138)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.View.measure(View.java:8366)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.LinearLayout.measureVertical(LinearLayout.java:531)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.LinearLayout.onMeasure(LinearLayout.java:309)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.View.measure(View.java:8366)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:3138)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.widget.FrameLayout.onMeasure(FrameLayout.java:250)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.View.measure(View.java:8366)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.ViewRoot.performTraversals(ViewRoot.java:844)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.view.ViewRoot.handleMessage(ViewRoot.java:1865)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.os.Handler.dispatchMessage(Handler.java:99)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.os.Looper.loop(Looper.java:123)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at android.app.ActivityThread.main(ActivityThread.java:3687)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at java.lang.reflect.Method.invokeNative(Native Method)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at java.lang.reflect.Method.invoke (Method.java:507)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:842)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:600)
04-10 02:25:13.057: E/AndroidRuntime(12302):
at dalvik.system.NativeStart.main(Native Method)
04-10 02:25:13.061: E/(129): Dumpstate > /data/log/dumpstate_app_error