Java android延迟加载库问题
我正在尝试在asynctask中异步下载一些图像,然后在onPostExecute()中将图像设置为库适配器。我已经硬编码了要在asyntask中加载的图像,因为我甚至无法到达将图像传递给适配器构造函数的部分:/ 不会抛出任何错误,postexecute Log()不会向logcat发布任何内容 有人能告诉我哪里出了问题吗 公共类GallerythreadedtestActivity扩展活动{Java android延迟加载库问题,java,android,Java,Android,我正在尝试在asynctask中异步下载一些图像,然后在onPostExecute()中将图像设置为库适配器。我已经硬编码了要在asyntask中加载的图像,因为我甚至无法到达将图像传递给适配器构造函数的部分:/ 不会抛出任何错误,postexecute Log()不会向logcat发布任何内容 有人能告诉我哪里出了问题吗 公共类GallerythreadedtestActivity扩展活动{ private Gallery gallery; private AddImgAdp adapter;
private Gallery gallery;
private AddImgAdp adapter;
private Drawable[] image;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
new downloadImages().execute();
}
public class AddImgAdp extends BaseAdapter {
int GalItemBg;
private Context cont;
// Adding images.
private Integer[] Imgid = {
R.drawable.icon, R.drawable.icon, R.drawable.icon, R.drawable.icon
};
public AddImgAdp(Context c) {
cont = c;
TypedArray typArray = obtainStyledAttributes(R.styleable.GalleryTheme);
GalItemBg = typArray.getResourceId(R.styleable.GalleryTheme_android_galleryItemBackground, 0);
typArray.recycle();
}
public int getCount() {
return Imgid.length;
}
public Object getItem(int position) {
return position;
}
public long getItemId(int position) {
return position;
}
public View getView(int position, View convertView, ViewGroup parent) {
ImageView imgView = new ImageView(cont);
imgView.setImageDrawable(image[position]);
// Fixing width & height for image to display
imgView.setLayoutParams(new Gallery.LayoutParams(80, 70));
imgView.setScaleType(ImageView.ScaleType.FIT_XY);
imgView.setBackgroundResource(GalItemBg);
return imgView;
}
}
public class downloadImages extends AsyncTask<String, Void, Void> {
protected void onPreExecute(){
image=new Drawable[2];
adapter = new AddImgAdp(getApplicationContext());
gallery = (Gallery) findViewById(R.id.examplegallery);
}
protected void onProgressUpdate(Void... v){
}
protected Void doInBackground(final String... args) {
image[0] = ImageOperations(getApplicationContext(),"http://t3.gstatic.com/images?q=tbn:ANd9GcQidl6KX2jRWNeCA6jT_TjWG7NlI3aRiB_AcDsA9Y5owS2cr9G6","image.jpg");
image[1] = ImageOperations(getApplicationContext(),"http://t3.gstatic.com/images?q=tbn:ANd9GcQidl6KX2jRWNeCA6jT_TjWG7NlI3aRiB_AcDsA9Y5owS2cr9G6","image.jpg");
return null;
}
protected void onPostExecute(){
Log.d("onpost","");
gallery.setAdapter(adapter);
gallery.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView parent, View v, int position, long id) {
Toast.makeText(GallerythreadedtestActivity.this, "Position=" + position, Toast.LENGTH_SHORT).show();
}
});
}
}
private Drawable ImageOperations(Context ctx, String url, String saveFilename) {
try {
InputStream is = (InputStream) this.fetch(url);
Drawable d = Drawable.createFromStream(is, "src");
return d;
} catch (MalformedURLException e) {
e.printStackTrace();
return null;
} catch (IOException e) {
e.printStackTrace();
return null;
}
}
public Object fetch(String address) throws MalformedURLException,IOException {
URL url = new URL(address);
Object content = url.getContent();
return content;
}
私人画廊;
专用AddImgAdp适配器;
私有可绘制图像;
@凌驾
创建时的公共void(Bundle savedInstanceState){
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
新建下载图像().execute();
}
公共类addimgapp扩展BaseAdapter{
int GalItemBg;
私人语境控制;
//添加图像。
私有整数[]Imgid={
R.drawable.icon,R.drawable.icon,R.drawable.icon,R.drawable.icon
};
公共AddImgAdp(上下文c){
cont=c;
TypedArray typArray=获取StyledAttributes(R.styleable.GalleryTheme);
GalItemBg=typArray.getResourceId(R.styleable.GalleryTheme\u android\u galleryItemBackground,0);
typArray.recycle();
}
public int getCount(){
返回Imgid.length;
}
公共对象getItem(int位置){
返回位置;
}
公共长getItemId(int位置){
返回位置;
}
公共视图getView(int位置、视图转换视图、视图组父视图){
ImageView imgView=新的ImageView(续);
imgView.setImageDrawable(图像[位置]);
//固定要显示的图像的宽度和高度
imgView.setLayoutParams(新图库.LayoutParams(80,70));
imgView.setScaleType(ImageView.ScaleType.FIT_XY);
imgView.setBackgroundResource(GalItemBg);
返回imgView;
}
}
公共类下载任务{
受保护的void onPreExecute(){
图像=新的可绘制[2];
adapter=newaddimgapp(getApplicationContext());
gallery=(gallery)findViewById(R.id.examplegallery);
}
受保护的void onProgressUpdate(void…v){
}
受保护的Void doInBackground(最终字符串…args){
图像[0]=图像操作(getApplicationContext(),”http://t3.gstatic.com/images?q=tbn:ANd9GcQidl6KX2jRWNeCA6jT_TjWG7NlI3aRiB_AcDsA9Y5owS2cr9G6“,”image.jpg“;
图像[1]=图像操作(getApplicationContext(),”http://t3.gstatic.com/images?q=tbn:ANd9GcQidl6KX2jRWNeCA6jT_TjWG7NlI3aRiB_AcDsA9Y5owS2cr9G6“,”image.jpg“;
返回null;
}
受保护的void onPostExecute(){
Log.d(“onpost”和“);
gallery.setAdapter(适配器);
gallery.setOnItemClickListener(新的OnItemClickListener(){
public void onItemClick(AdapterView父视图、视图v、整型位置、长id){
Toast.makeText(GallerythreadedtestActivity.this,“Position=“+Position,Toast.LENGTH_SHORT).show();
}
});
}
}
私有可绘制图像操作(上下文ctx、字符串url、字符串保存文件名){
试一试{
InputStream为=(InputStream)this.fetch(url);
Drawable d=Drawable.createFromStream(是“src”);
返回d;
}捕获(格式错误){
e、 printStackTrace();
返回null;
}捕获(IOE异常){
e、 printStackTrace();
返回null;
}
}
公共对象获取(字符串地址)引发畸形DurLexException,IOException{
URL=新的URL(地址);
Object content=url.getContent();
返回内容;
}
}我可以给你一个建议,请尝试这也是一个补充解决方案,最好延迟加载图像:。如果您将xml中的列表视图元素更改为Gallery视图,我认为这将解决您的问题