Question

我有一个GridView，我想在点击一个按钮后更新它（我想在点击后更改文本和按钮的颜色）。我尝试使用notifyDataSetChanged（）;在onClick方法中，但什么也没发生。

我使用Asynctask将数据存储在我的sharedPrefereces中（在PostExecute中），此数据的一部分是＆＃34; brandName＆＃34;我点击的项目/按钮。我尝试使用notifyDataSetChanged（）更新de View;在PostExecute方法中但不起作用。

我比较getView方法中的数据来改变存储在sharedprefereces中的brandButton的颜色，如果我点击其他按钮，我想刷新视图。

Pd积。抱歉我的英语不好

这是我的getView方法

public View getView(final int position, View convertView, ViewGroup parent) {
    // TODO Auto-generated method stub
    View grid;
    LayoutInflater inflater = (LayoutInflater) mContext
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

    if (convertView == null) {
        grid = new View(mContext);
        grid = inflater.inflate(R.layout.grid_single, null);
        TextView brandName = (TextView) grid.findViewById(R.id.grid_text);
        ImageView brandLogo = (ImageView) grid.findViewById(R.id.grid_image);
        ImageView twitterImg = (ImageView) grid.findViewById(R.id.twitterImg);
        ImageView facebookImg = (ImageView) grid.findViewById(R.id.facebookImg);
        ImageView instagramImg = (ImageView) grid.findViewById(R.id.instagramImg);
        Button selectBrand = (Button) grid.findViewById(R.id.selectBrand);

        if(mBrandGenericData.getDataList().get(position).socialList.size()>0){
            for(int i=0; i<mBrandGenericData.getDataList().get(position).socialList.size(); i++){
                if(mBrandGenericData.getDataList().get(position).socialList.get(i).socialType.equalsIgnoreCase("FB")){
                    facebookImg.setImageDrawable(facebookDrawable);
                }
                if(mBrandGenericData.getDataList().get(position).socialList.get(i).socialType.equalsIgnoreCase("TW")){
                    twitterImg.setImageDrawable(twitterDrawable);
                }
                if(mBrandGenericData.getDataList().get(position).socialList.get(i).socialType.equalsIgnoreCase("IT")){
                    instagramImg.setImageDrawable(instagramDrawable);
                }
            }
        }
        new ImageLoadTask("http://api.socialmanageranalytics.com/"+mBrandGenericData.getDataList().get(position).logo, brandLogo).execute();
        brandName.setText(mBrandGenericData.getDataList().get(position).name);
//Here i change the color and text of my button         
        if (brandName.getText().equals(PreferenceManager.getDefaultSharedPreferences(mContext).getString("brandName", ""))){
            selectBrand.setText(R.string.selected);
            selectBrand.setBackgroundColor(0xFF18abd5);
        }
        selectBrand.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View arg0) {
                // TODO Auto-generated method stub
                new SelectBrandTask("http://api.socialmanageranalytics.com/"+mBrandGenericData.getDataList().get(position).logo, mBrandGenericData.getDataList().get(position).name, mBrandGenericData.getDataList().get(position).id).execute();
                CustomGrid.this.notifyDataSetChanged();
            }
        });
    } else {
        grid = (View) convertView;
    }

    return grid;
}

这是我的AsyncTask

public class SelectBrandTask extends AsyncTask<Void, Void, Bitmap> {

    private String url;
    private String brandName;
    private String id;
    private ProgressDialog dialog;

    public SelectBrandTask(String url, String brandName, String id) {
        this.url = url;
        this.brandName = brandName;
        this.id = id;
    }

    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        dialog = ProgressDialog.show(mContext, "Seleccionando marca",
                    "Por favor espere...");
    }

    @Override
    protected Bitmap doInBackground(Void... params) {
        try {
            URL urlConnection = new URL(url);
            HttpURLConnection connection = (HttpURLConnection) urlConnection
                    .openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream input = connection.getInputStream();
            Bitmap myBitmap = BitmapFactory.decodeStream(input);
            return myBitmap;
        } catch (Exception e) {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Bitmap result) {
        super.onPostExecute(result);
        SharedPreferences myPreference = PreferenceManager.getDefaultSharedPreferences(mContext);
        SharedPreferences.Editor editor = myPreference.edit();
        editor.putString("brandName", brandName);
        editor.putString("user", user);
        editor.putString("brandImage", encodeTobase64(result));
        editor.putString("brandId", id);
        editor.commit();

        if (dialog != null)
            dialog.dismiss();

        CustomGrid.this.notifyDataSetChanged();

    }

请提前帮助我。

Answer 1

问题是，您只是在convertView == null时设置了您的观看次数值，在您调用getView()的前几次后，您的情况可能不会这样。

如果移动调用以将TextView的文本/颜色设置为convertView为空的块之外，则在下载数据后，代码应该可以正常工作。

由于您必须将TextView的声明移动到方法之外，因此您应该使用某种ViewHolder来使您的生活更轻松，并且适配器更高效。 http://www.javacodegeeks.com/2013/09/android-viewholder-pattern-example.html实际上可以很好地解释它，但这里与你的代码有点相关：

public View getView(final int position, View convertView, ViewGroup parent) {
    final BrandsHolder holder;
    if(convertView == null){
        holder = new BrandsHolder();
        convertView = inflater.inflate(R.layout.grid_single, parent, false);

        holder.brandName = (TextView)convertView.findViewById(R.id.grid_text);
        .... // The rest of your item declarations

        convertView.setTag(holder);
    }
    else holder = (BrandsHolder)convertView.getTag();

    final BrandGenericData brandData = BrandGenericData.getDataList().get(position);

    new ImageLoadTask("http://api.socialmanageranalytics.com/" + brand.logo, holder.brandLogo).execute();

    holder.brandName.setText(brand.name);
    if (holder.brandName.getText().equals(PreferenceManager.getDefaultSharedPreferences(mContext).getString("brandName", ""))){
        holder.selectBrand.setText(R.string.selected);
        holder.selectBrand.setBackgroundColor(0xFF18abd5);
    }

    ... // Any other adjustments you want to make for each item
}

private class BrandsHolder {
    TextView brandName;
    ImageView brandLogo;
    Button selectBrand;
    ... // The rest of your ViewHolder's variable declarations
}

代码需要你填写其余部分，但我认为这应该指向正确的方向。

更新Asynctask中的GridView并不起作用

1 个答案: