我写了一个Android应用程序，到目前为止，除了在一部手机上它完美无缺。这是我在2.2手机和手机上的确切手机。另一部手机正在逐渐关闭，但仅在打开查询我的图像数据库并尝试显示图库的活动时。每个活动都在同一个地方崩溃，即视图。起初我以为是这样做的意图，但其中一个活动没有意图，它打开了画廊下面的图像。这适用于模拟器，我的机器人机器人和其他一些不同的机器人。这是图库和我的位图解码器的代码。错误低于此。如果有人能看到任何会让它崩溃的东西，我真的很感激帮助。
public void viewimages() {
String [] proj={ImageProvider._ID, ImageProvider.IMAGE, ImageProvider.TABLENAME,
ImageProvider.ITEMID, ImageProvider.IMAGEDATE};
cursor = managedQuery(ImageProvider.CONTENT_URI,
proj,
ImageProvider.TABLENAME + "=" + "'" + Tablename + "'"
+ " and " + ImageProvider.ITEMID + "=" + "'" + ID + "'",
null,
ImageProvider.IMAGEDATE);
第182行 - ＆gt; column_index = cursor.getColumnIndex（ImageProvider._ID）;
g = (Gallery) findViewById(R.id.gallery);
g.setAdapter(new ImageAdapter(this));
g.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View v, int position, long id) {
cursor.moveToPosition(position);
ImageID = cursor.getLong(column_index);
Intent i = new Intent(LivestockDetails.this, ImageViewer.class);
i.putExtra("id", ImageID);
startActivity(i);
}
});
}
private Bitmap decodeFile(String file){
Bitmap b = null;
//Decode image size
BitmapFactory.Options o = new BitmapFactory.Options();
o.inJustDecodeBounds = true;
BitmapFactory.decodeFile(file, o);
int scale = 1;
if (o.outHeight > IMAGE_MAX_SIZE || o.outWidth > IMAGE_MAX_SIZE) {
scale = 2 ^ (int) Math.ceil(Math.log(IMAGE_MAX_SIZE / (double) Math.max(o.outHeight, o.outWidth)) / Math.log(0.5));
}
//Decode with inSampleSize
BitmapFactory.Options o2 = new BitmapFactory.Options();
o2.inSampleSize = scale;
b = BitmapFactory.decodeFile(file, o2);
return b;
}
public class ImageAdapter extends BaseAdapter {
int mGalleryItemBackground;
public ImageAdapter(Context c) {
mContext = c;
TypedArray a = obtainStyledAttributes(R.styleable.Gallery1);
mGalleryItemBackground = a.getResourceId(
R.styleable.Gallery1_android_galleryItemBackground, 0);
a.recycle();
}
public int getCount() {
return cursor.getCount();
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView i = new ImageView(mContext);
if (convertView == null) {
String [] proj={ImageProvider._ID, ImageProvider.IMAGE, ImageProvider.TABLENAME,
ImageProvider.ITEMID, ImageProvider.IMAGEDATE};
cursor = managedQuery(ImageProvider.CONTENT_URI,
proj,
ImageProvider.TABLENAME + "=" + "'" + Tablename + "'"
+ " and " + ImageProvider.ITEMID + "=" + "'" + ID + "'",
null,
ImageProvider.IMAGEDATE + " DESC");
column_path = cursor.getColumnIndex(ImageProvider.IMAGE);
column_index = cursor.getColumnIndex(ImageProvider._ID);
cursor.moveToPosition(position);
String filename = cursor.getString(column_path);
java.io.File file = new java.io.File(filename);
if(!file.exists()) {
ImageID = cursor.getLong(column_index);
getContentResolver().delete(ImageProvider.CONTENT_URI,
ImageProvider._ID + "=" + ImageID, null);
Toast.makeText(LivestockDetails.this,
"There are missing images. They have been removed from the database." ,
Toast.LENGTH_LONG).show();
viewimages();
}
else {
Bitmap bitmapOrg = null;
bitmapOrg = decodeFile(filename);
Matrix matrix = new Matrix();
matrix.postScale(scale,scale);
resizedBitmap = Bitmap.createBitmap(bitmapOrg, 0, 0,
bitmapOrg.getWidth(), bitmapOrg.getHeight(), matrix, true);
Drawable delete = i.getDrawable();
if(delete!= null) {
((BitmapDrawable)i.getDrawable()).getBitmap().recycle();
i.setImageBitmap(resizedBitmap);
}
else {
i.setImageBitmap(resizedBitmap);
}
i.setScaleType(ImageView.ScaleType.FIT_XY);
i.setLayoutParams(new Gallery.LayoutParams(240, 180));
i.setBackgroundResource(mGalleryItemBackground);
}
}
return i;
}
}
这是错误
java.lang.RuntimeException: Unable to start activity ComponentInfo{myaquarium.logger/myaquarium.logger.LivestockDetails}: java.lang.NullPointerException
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2663)
at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2679)
at android.app.ActivityThread.access$2300(ActivityThread.java:125)
at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2033)
at android.os.Handler.dispatchMessage(Handler.java:99)
at android.os.Looper.loop(Looper.java:123)
at android.app.ActivityThread.main(ActivityThread.java:4627)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:521)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:868)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:626)
at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.NullPointerException
at myaquarium.logger.LivestockDetails.viewimages(LivestockDetails.java:182)
at myaquarium.logger.LivestockDetails.onCreate(LivestockDetails.java:71)
at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1047)
at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2627)
... 11 more
答案 0 :(得分：1)
我终于明白了。我的内容提供商搞砸了。我有两个应用程序，一个用于我的测试，一个用于发布。我有用于发布的内容提供商指向我的测试应用程序，因此在模拟器中它工作正常，因为内容提供商在那里，但当有人清除我的应用程序时，缺少提供者。如果只有错误报告提供了更多信息。当我通过卸载所有内容在我的模拟器上复制它然后只安装主应用程序logcat告诉我，无法找到内容提供商。这就是为什么它每次都会在光标上崩溃。