嗨，我自己是 android 的新手，我已经完成了从数据库中搜索特定记录并使用简单的光标适配器显示它的列表的代码，以使用我开始使用自定义适配器的数据来获取图像，当我尝试检索时代码工作得很好来自 db 的所有数据，但是当我将参数传递给 db 中的方法以搜索特定记录并将其显示在列表中时出现错误
这是我的代码，当用户选择要显示的数据时传递
Intent i= new Intent(SearchByBed.this,SearchBedView.class);
Bundle bbed= new Bundle();
bbed.putString("bedValue", spinn_Bed.getSelectedItem().toString());
i.putExtras(bbed);
startActivity(i);
在这部分中，从上一个类传递的参数是 catch，然后传递给 db 并想要检索记录并将其绑定到 custom-adapter
my asynctask code
public class loadSomeStuff extends AsyncTask<String, Integer, String> {
ProgressDialog dialog;
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
dialog = new ProgressDialog(SearchBedView.this);
dialog.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
dialog.setMax(100);
dialog.setMessage("Loading Data");
dialog.show();
}
@Override
protected void onProgressUpdate(Integer... values) {
// TODO Auto-generated method stub
dialog.incrementProgressBy(values[0]);
}
@Override
protected String doInBackground(String... params) {
// TODO Auto-generated method stub
for (int i = 0; i < 20; i++) {
publishProgress(5);
try {
Thread.sleep(100);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
dialog.dismiss();
return null;
}
@Override
protected void onPostExecute(String result) {
// TODO Auto-generated method stub
displaydemo();
}
}
public void displaydemo() {
// TODO Auto-generated method stub
Bundle bbedview = this.getIntent().getExtras();
name = bbedview.getString("name").toString();
//data.setText(name); //as per log here i was getting null pointer exception but
//know commented as it was line from my previous code
info = new PropertyInfo(this);
info.open();
cursor = info.getBed(name);
String[] from = new String[] { PropertyInfo.KEY_ROWID,
PropertyInfo.KEY_TYPE, PropertyInfo.KEY_BEDROOMS,
PropertyInfo.KEY_STATUS, PropertyInfo.KEY_CITY,
PropertyInfo.KEY_FURNISHING, PropertyInfo.KEY_TOTPRICE };
int[] to = new int[] { R.id.rowId, R.id.rowtype, R.id.rowBed,
R.id.rowStatus, R.id.rowCity, R.id.rowFurnish,
R.id.rowTotalPrice };
custAdapter = new CustomContactsAdapterBedView(this, R.layout.row, cursor,
from, to);
this.setListAdapter(custAdapter);
}
虽然这是 mycustomadapter 类
public class CustomContactsAdapterBedView extends SimpleCursorAdapter {
private int layout;
LayoutInflater inflator;
TextView tid,ttype,tbed,tstatus,tcity,tfurnish,ttotprice;
public CustomContactsAdapterBedView(Context context, int layout, Cursor c,
String[] from, int[] to) {
super(context, layout, c, from, to, 0);
this.layout = layout;
inflator = LayoutInflater.from(context);
}
public View newView(Context context, Cursor cursor, ViewGroup parent) {
View v = inflator.inflate(layout, parent, false);
return v;
}
@Override
public void bindView(View v, final Context context, Cursor c) {
final String id = c.getString(c.getColumnIndex(PropertyInfo.KEY_ROWID));
final String type = c
.getString(c.getColumnIndex(PropertyInfo.KEY_TYPE));
final String bed = c.getString(c
.getColumnIndex(PropertyInfo.KEY_BEDROOMS));
final String status = c.getString(c
.getColumnIndex(PropertyInfo.KEY_STATUS));
final String city = c
.getString(c.getColumnIndex(PropertyInfo.KEY_CITY));
final String furnish = c.getString(c
.getColumnIndex(PropertyInfo.KEY_FURNISHING));
final String totprice = c.getString(c
.getColumnIndex(PropertyInfo.KEY_TOTPRICE));
final byte[] image = c.getBlob(c.getColumnIndex(PropertyInfo.IMAGE));
ImageView iv = (ImageView) v.findViewById(R.id.photo);
if (image != null) {
if (image.length > 3) {
iv.setImageBitmap(BitmapFactory.decodeByteArray(image, 0,
image.length));
}
}
tid = (TextView) v.findViewById(R.id.rowId);
tid.setText(id);
ttype = (TextView) v.findViewById(R.id.rowtype);
ttype.setText(type);
tbed = (TextView) v.findViewById(R.id.rowBed);
tbed.setText(bed);
tstatus = (TextView) v.findViewById(R.id.rowStatus);
tstatus.setText(status);
tcity = (TextView) v.findViewById(R.id.rowCity);
tcity.setText(city);
tfurnish = (TextView) v.findViewById(R.id.rowFurnish);
tfurnish.setText(furnish);
ttotprice = (TextView) v.findViewById(R.id.rowTotalPrice);
ttotprice.setText(totprice);
}
}
db中的方法如下
public Cursor getBed(String l) {
String[] columns = new String[] { KEY_ROWID, KEY_TITLE, KEY_TYPE,
KEY_BEDROOMS, KEY_STATUS, KEY_CITY, KEY_LOCALITY, KEY_PRICE,
KEY_TOTPRICE, KEY_FURNISHING, KEY_BALCONIES, KEY_BATHROOM,
IMAGE };
Cursor c = ourDatabase.query(DATABASE_TABLE, columns, KEY_BEDROOMS
+ "=" + l, null, null, null, null);
return c;
}
logcat中的错误是
05-16 20:33:43.803: E/AndroidRuntime(31444): FATAL EXCEPTION: main
05-16 20:33:43.803: E/AndroidRuntime(31444): java.lang.NullPointerException
05-16 20:33:43.803: E/AndroidRuntime(31444): at
com.project.realestate.SearchBedView.displaydemo(SearchBedView.java:299)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
com.project.realestate.SearchBedView$loadSomeStuff.onPostExecute(SearchBedView.java:281)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
com.project.realestate.SearchBedView$loadSomeStuff.onPostExecute(SearchBedView.java:1)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.os.AsyncTask.finish(AsyncTask.java:631)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.os.AsyncTask.access$600(AsyncTask.java:177)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.os.AsyncTask$InternalHandler.handleMessage(AsyncTask.java:644)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.os.Handler.dispatchMessage(Handler.java:99)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.os.Looper.loop(Looper.java:137)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
android.app.ActivityThread.main(ActivityThread.java:5041)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
java.lang.reflect.Method.invokeNative(Native Method)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
java.lang.reflect.Method.invoke(Method.java:511)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560)
05-16 20:33:43.803: E/AndroidRuntime(31444): at
dalvik.system.NativeStart.main(Native Method)
请帮助我的代码