Question

我正在构建一个显示两个水平滚动视图的活动。顶部的图像保存大图像，而较低的图像保存这些图像的缩略图。当用户点击缩略图时，上部滚动视图将自动滚动到与缩略图对应的图像。我的问题是布局的getWidth（）方法总是返回0.我在运行时创建布局然后调用getwidth（）方法，所以它应该返回正确的值，但它不是。

public class ZoomActivity extends Activity {
    private final String THUMBS="http://kurdshopping.net/thumbs/";
    private final String UPLOADS="http://kurdshopping.net/uploads/";
    private ImageView imageView;
    private String path;
    private String[] filenames;
    private LinearLayout l1,l2;
    private int[] widths=null;
    private HorizontalScrollView hsv=null;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        requestWindowFeature(Window.FEATURE_INDETERMINATE_PROGRESS);
        setContentView(R.layout.activity_zoom);

        ActionBarUtils.setActionBar(this);

        path = getIntent().getExtras().getString("path");
        filenames=getIntent().getExtras().getStringArray("images");
        widths=new int[filenames.length];
        l1=(LinearLayout) findViewById(R.id.LinearLayout1);
        l2=(LinearLayout) findViewById(R.id.LinearLayout2);
        hsv=(HorizontalScrollView) findViewById(R.id.horizontalScrollView1);

        for(int i=0; i<filenames.length; i++){
            BitmapLoaderTask task = new BitmapLoaderTask(i);
            task.execute(UPLOADS+filenames[i],"1");
        }
        for(int i=0;i<filenames.length;i++){
            BitmapLoaderTask task = new BitmapLoaderTask(i);
            task.execute(THUMBS+filenames[i],"2");
        }
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.zoom, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
        case android.R.id.home:
            finish();
            break;
//      case R.id.action_all:
//          Intent allitemIntent = new Intent(MainActivity.this,
//                  AllItemsActivity.class);
//          startActivity(allitemIntent);
//          break;
//      case R.id.action_search:
//          Intent search = new Intent(this, SearchDialogActivity.class);
//          startActivity(search);
//          break;
        }
        return super.onOptionsItemSelected(item);
    }

    private void setImageBitmap(Bitmap bmp) {
        imageView = new ScrollableImageView(this);
        imageView.setLayoutParams(new LayoutParams(bmp.getWidth(), bmp
                .getHeight()));
        imageView.setImageBitmap(bmp);
        ViewGroup root = (ViewGroup) findViewById(android.R.id.content);
        root.addView(imageView);
    }

    private class BitmapLoaderTask extends AsyncTask<String, Void, Bitmap> {
        private String layout;
        private int index;
        private int x_coords=0;
        public BitmapLoaderTask(int index){
            super();
            this.index=index;
        }

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
            setProgressBarIndeterminateVisibility(true);
        }

        @Override
        protected synchronized Bitmap doInBackground(String... params) {
//          AssetManager assets = getAssets();
            Bitmap bmp = null;
            layout=params[1];
            try {
                URL url = new URL(params[0]);
                bmp = BitmapFactory.decodeStream(url.openConnection()
                        .getInputStream());

            } catch (IOException e) {
                Log.e("ZoomActivity", e.getMessage(), e);
            }
            return bmp;
        }

        @Override
        protected void onPostExecute(Bitmap result) {
            super.onPostExecute(result);
            View view=null;
            try {
                view=ImageUtils.insertPhoto(ZoomActivity.this, result);
            } catch (MalformedURLException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            } catch (IOException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
            if(layout.equals("1")){
                l1.addView(view);
                view.setTag(x_coords);
                x_coords+=((LinearLayout)view).getMeasuredWidth();// this is always returning 0, view.getLayoutParams().width is also same.
            }else{
                l2.addView(view);
                ImageView img=(ImageView) ((LinearLayout)view).getChildAt(0);
                img.setTag(index);
                img.setOnClickListener(new OnClickListener() {

                    @Override
                    public void onClick(View v) {
                        int index=(Integer) v.getTag();
                        LinearLayout layout = (LinearLayout) l1.getChildAt(index);
                        int x=(Integer) layout.getTag();
                        hsv.scrollTo(x, 0);
                    }
                });
            }
//          ImageView imageview=(ImageView) findViewById(R.id.imageView1);
//          imageview.setImageBitmap(result);
//          setImageBitmap(result);
            setProgressBarIndeterminateVisibility(false);
        }
    }
}

我正在创建布局的insertPhoto函数 -

public static View insertPhoto(final Activity activity, Bitmap bm) throws MalformedURLException, IOException {
        LinearLayout layout = new LinearLayout(activity.getApplicationContext());
        layout.setLayoutParams(new LayoutParams(bm.getWidth()+10, bm.getHeight()+10));
        layout.setGravity(Gravity.CENTER);

        final ImageView imageView = new ImageView(
                activity.getApplicationContext());
        imageView.setLayoutParams(new LayoutParams(bm.getWidth(), bm.getHeight()));
        imageView.setScaleType(ImageView.ScaleType.FIT_CENTER);
        imageView.setImageBitmap(bm);
//      imageView.setTag(filename);

        layout.addView(imageView);
        return layout;
    }

提前感谢您的帮助。

编辑：我只发布需要宽度的代码部分。我修改它以使用viewtreeoserver但它仍然无法工作 -

l1.addView(view);
                    view.setTag(x_coords);
                    view.requestLayout();
                    ViewTreeObserver vto=view.getViewTreeObserver();
                    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

                        @Override
                        public void onGlobalLayout() {
                            x_coords+=((LinearLayout)view).getMeasuredWidth();
                        }
                    });

Answer 1

在使用get width method-

之前尝试使用此代码

yourlayout.requestLayout();

希望这可以帮助你!!!

如果不能正常工作，请告诉我，我会尽力帮助您。

修改答案

试试这段代码 -

l1.addView(view);
                    view.setTag(x_coords);
                    view.requestLayout();
                    ViewTreeObserver vto=view.getViewTreeObserver();
                    vto.addOnGlobalLayoutListener(new OnGlobalLayoutListener() {

                        @Override
                        public void onGlobalLayout() {
                                           view.getViewTreeObserver().removeGlobalOnLayoutListener(this);   
                            x_coords+=((LinearLayout)view).getMeasuredWidth();
                        }
                    });

getWidth（）方法返回0

1 个答案: