我有一个问题我无法解决qal。 我已经尝试过所有方法。 这是AsyncTask中的一个问题，它不应该是正确的。
有人能以正确的方式告诉我。
public class ExibeGallery extends SherlockActivity {
private Gallery galleryView1;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.exibegallery);
Log.i("19", "Chama a gallery");
AdaptadordaImagem adp = new AdaptadordaImagem(this);
galleryView1 = (Gallery) findViewById(R.id.GaleryView);
galleryView1.setAdapter(adp);
}
}
public class AdaptadordaImagem extends BaseAdapter {
private Context cont;
int GalItemBg;
private String[] myRemoteImages = {
"http://www.cuboweb.com.br/android/images/1.png",
"http://www.cuboweb.com.br/android/images/2.png",
"http://www.cuboweb.com.br/android/images/3.png",
"http://www.cuboweb.com.br/android/images/4.png", };
static Bitmap bm;
private int[] img = {0, 1, 2, 3};
BitmapFactory.Options bmOptions;
private Object mGalleryItemBackground;
ImageView i = null;
public AdaptadordaImagem(Context c) {
cont = c;
i = new ImageView(this.cont);
PegaImagens pg = new PegaImagens();
pg.execute();
Log.i("1", "Adaptador de imagem");
}
private TypedArray obtainStyledAttributes(int[] hellogallery) {
// TODO Auto-generated method stub
return null;
}
public int getCount() {
return this.img.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
Log.i("2", "getView");
ImageView i = new ImageView(cont);
i.setBackgroundResource(img[position]);
i.setLayoutParams(new Gallery.LayoutParams(150, 100));
i.setBackgroundResource((Integer) mGalleryItemBackground);
i.setAdjustViewBounds(true);
return i;
}
public class PegaImagens extends AsyncTask<String[], Void, String> {
private ProgressDialog progressgallery;
protected void onPreExecute() {
Log.i("3", "AsyncTask onPreexecute");
progressgallery = new ProgressDialog(cont, GalItemBg);
progressgallery.setTitle("Aguarde...");
progressgallery.setMessage("Carregando...");
progressgallery.show();
}
public Bitmap loadBitmap(String[] myRemoteImages, BitmapFactory.Options options) {
Log.i("4", "AsyncTask loadBitmap");
InputStream in = null;
int i;
for (i = 0; i <= 3; i++) {
Log.i("5", "AsyncTask loadBitmap for");
try {
Log.i("5", "AsyncTask loadBitmap for try");
in = OpenHttpConnection(myRemoteImages[i]);
bm = BitmapFactory.decodeStream(in, null, options);
in.close();
} catch (IOException e1) {
Log.i("6", "AsyncTask loadBitmap for catch");
bm = null;
}
}
return bm;
}// aqui fecha o load bitmap
private InputStream OpenHttpConnection(String myRemoteImages) throws IOException {
Log.i("6", "AsyncTask OpenHttpConnection");
InputStream inputStream = null;
URL url = new URL(myRemoteImages);
URLConnection conn = url.openConnection();
try {
Log.i("7", "AsyncTask OpenHttpConnection try");
HttpURLConnection httpConn = (HttpURLConnection) conn;
httpConn.setRequestMethod("GET");
httpConn.connect();
InputStream is = conn.getInputStream();
BufferedInputStream bis = new BufferedInputStream(is);
Bitmap bm = BitmapFactory.decodeStream(bis);
bis.close();
is.close();
i.setImageBitmap(bm);
if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
Log.i("8", "AsyncTask OpenHttpConnection try if");
inputStream = httpConn.getInputStream();
}
} catch (Exception ex) {
Log.i("9", "AsyncTask OpenHttpConnection catch");
i.setImageResource(R.drawable.sem_conexao);
}
return inputStream;
}// aqui fecha o InputStream
protected String doInBackground(String[]... params) {
// TODO Auto-generated method stub
Log.i("10", "AsyncTask doInBackground");
int x;
for (x = 0; x <= 3; x++) {
Log.i("11", "AsyncTask doInBackground for");
try {
Log.i("12", "AsyncTask doInBackground for try");
bmOptions = new BitmapFactory.Options();
bmOptions.inSampleSize = 1;
} catch (ArrayIndexOutOfBoundsException erro) {
Log.i("13", "AsyncTask doInBackground for try catch1");
myRemoteImages[x] = "";
} catch (Exception erro) {
Log.i("14", "AsyncTask doInBackground for try catch2");
myRemoteImages[x] = "";
}
}
loadBitmap(myRemoteImages, bmOptions);
return myRemoteImages[x];
}
protected void onPostExecute(String[] myRemoteImages) {
Log.i("15", "AsyncTask onPostExecute ");
if (!myRemoteImages.equals("")) {
// ok
Log.i("16", "AsyncTask onPostExecute if ok ");
TypedArray a = obtainStyledAttributes(R.styleable.HelloGallery);
mGalleryItemBackground = a.getResourceId(R.styleable.HelloGallery_android_galleryItemBackground, 0);
a.recycle();
} else {
Log.i("17", "AsyncTask onPostExecute else falha ");
}
progressgallery.dismiss();
}
}// end async task
}// end class
错误日志： -
11-07 11:51:12.865: W/dalvikvm(529): threadid=1: thread exiting with uncaught exception (group=0x40014760)
11-07 11:51:12.875: E/AndroidRuntime(529): FATAL EXCEPTION: main
11-07 11:51:12.875: E/AndroidRuntime(529): java.lang.NullPointerException
11-07 11:51:12.875: E/AndroidRuntime(529): at br.com.consulfarma.acs.AdaptadordaImagem.getView(AdaptadordaImagem.java:71)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.AbsSpinner.onMeasure(AbsSpinner.java:192)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4351)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1284)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.measureHorizontal(LinearLayout.java:956)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.onMeasure(LinearLayout.java:521)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4351)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.FrameLayout.onMeasure(FrameLayout.java:267)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.measureVertical(LinearLayout.java:764)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.onMeasure(LinearLayout.java:519)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4351)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.FrameLayout.onMeasure(FrameLayout.java:267)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4351)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1284)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.measureVertical(LinearLayout.java:613)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.LinearLayout.onMeasure(LinearLayout.java:519)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:4351)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.widget.FrameLayout.onMeasure(FrameLayout.java:267)
11-07 11:51:12.875: E/AndroidRuntime(529): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:1890)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.View.measure(View.java:10828)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewRoot.performTraversals(ViewRoot.java:909)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.view.ViewRoot.handleMessage(ViewRoot.java:2003)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.os.Handler.dispatchMessage(Handler.java:99)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.os.Looper.loop(Looper.java:132)
11-07 11:51:12.875: E/AndroidRuntime(529): at android.app.ActivityThread.main(ActivityThread.java:4025)
11-07 11:51:12.875: E/AndroidRuntime(529): at java.lang.reflect.Method.invokeNative(Native Method)
11-07 11:51:12.875: E/AndroidRuntime(529): at java.lang.reflect.Method.invoke(Method.java:491)
11-07 11:51:12.875: E/AndroidRuntime(529): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841)
11-07 11:51:12.875: E/AndroidRuntime(529): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599)
11-07 11:51:12.875: E/AndroidRuntime(529): at dalvik.system.NativeStart.main(Native Method)
答案 0 :(得分：0)
失败的行如下：
ImageView i = new ImageView(this.cont);
将此行添加到构造函数中，如下所示：
//this line edited;
ImageView i = null;
public AdaptadordaImagem(Context c) {
cont = c;
//this line added
i = new ImageView(this.cont);
PegaImagens pg = new PegaImagens();
pg.execute();
Log.i("1", "Adaptador de imagem");
}
甚至删除它，因为在您的代码中似乎并没有真正使用它（在getView方法上创建新的ImageView i）。
希望它有所帮助。 Saludos
答案 1 :(得分：0)
看起来你的img从未被初始化，至少在发布的代码中。如果是这样，getCount（）正确地为空。
如果这是真的，你需要这样的东西：
private int[] img = someIntArrayWithYourIds;
修改：澄清：
尝试在getCount中设置此行中的调试器断点，并查看img和img.length的值：
return this.img.length;
很可能，img在那里是空的。