图片中的Andr​​oid GridView的变化。怎么样？ [英] Images in Android GridView changes. How?

问题描述

  

我使用我的应用程序的标准gridview的来源。这是我面临的问题是，当我在GridView滚动图像时，图像动态改变每次，具有位置错误的图像。仅供参考下面是code I使用......

  @覆盖
公共无效的onCreate（捆绑savedInstanceState）{
    super.onCreate（savedInstanceState）;
    的setContentView（R.layout.main）;    //设置我们想要的缩略图ID列的一个阵列
    的String [] =投影{MediaStore.Images.Thumbnails._ID};
    //创建光标指向SD卡
    光标= managedQuery（MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI，
            投影，//哪些列返回
            空，//返回所有行
            空值，
            MediaStore.Images.Thumbnails.IMAGE_ID）;
    //获取缩略图图片ID列索引
    参数：columnIndex = cursor.getColumnIndexOrThrow（MediaStore.Images.Thumbnails._ID）;    GridView控件的GridView =（GridView控件）findViewById（R.id.gridview）;
    gridView.setAdapter（新ImageAdapter（本））;
    gridView.setOnItemClickListener（新OnItemClickListener（）{
        @覆盖
        公共无效onItemClick（适配器视图＆LT;＆GT;母公司，视图V，
                INT位置，长的id）{            //发送图片ID来FullScreenActivity
            意图I =新意图（getApplicationContext（），ImageSelection.class）;
            //传递数组索引
            i.putExtra（imageIndex_from_Activity位置）;
            startActivity（ⅰ）;        }
    }）;
 

> ImageAdapter类

 私有类ImageAdapter延伸BaseAdapter {    私人上下文的背景下;    公共ImageAdapter（上下文localContext）{
        上下文= localContext;
    }    公众诠释的getCount（）{
        返回cursor.getCount（）;
    }
    公共对象的getItem（INT位置）{
        返回的位置;
    }
    众长getItemId（INT位置）{
        返回的位置;
    }
    公共查看getView（INT位置，查看convertView，父母的ViewGroup）{
        ImageView的picturesView;
        如果（convertView == NULL）{
            picturesView =新ImageView的（上下文）;
            //将光标移动到当前位置
            cursor.moveToPosition（位置）;
            //获取被请求的列的当前值
            INT imageID = cursor.getInt（参数：columnIndex）;
            //设置基于所提供的URI的图像的内容
            picturesView.setImageURI（Uri.withAppendedPath（
                    MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI，+ imageID））;
            picturesView.setScaleType（ImageView.ScaleType.FIT_CENTER）;
            picturesView.setPadding（5,5，5,5）;
            picturesView.setLayoutParams（新GridView.LayoutParams（80，80））;
        }
        其他{
            picturesView =（ImageView的）convertView;
        }
        返回picturesView;
    }
}
 

  

附加截图，1.Before滚动2.Scrolled下来，再向上滚动。

  

为什么顺序的变化？

解决方案

您只设置新的图片视图。

执行以下操作：

 如果（convertView == NULL）{
    picturesView =新ImageView的（上下文）;
    picturesView.setScaleType（ImageView.ScaleType.FIT_CENTER）;
    picturesView.setPadding（5,5，5,5）;
    picturesView.setLayoutParams（新GridView.LayoutParams（80，80））;
}其他{
    picturesView =（ImageView的）convertView;
}
//将光标移动到当前位置
cursor.moveToPosition（位置）;
//获取被请求的列的当前值
INT imageID = cursor.getInt（参数：columnIndex）;
//设置基于所提供的URI的图像的内容
picturesView.setImageURI（Uri.withAppendedPath（
MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI，+ imageID））;
 

I am using the standard gridview source for my app. The problem which i face is that, when i scroll the images in the gridview, the images change dynamically everytime, having wrong images at the positions. For reference below is the code i use......

  @Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.main);

    // Set up an array of the Thumbnail Image ID column we want
    String[] projection = {MediaStore.Images.Thumbnails._ID};
    // Create the cursor pointing to the SDCard
    cursor = managedQuery( MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI,
            projection, // Which columns to return
            null,       // Return all rows
            null,
            MediaStore.Images.Thumbnails.IMAGE_ID);
    // Get the column index of the Thumbnails Image ID
    columnIndex = cursor.getColumnIndexOrThrow(MediaStore.Images.Thumbnails._ID);

    GridView gridView = (GridView) findViewById(R.id.gridview);
    gridView.setAdapter(new ImageAdapter(this));




    gridView.setOnItemClickListener(new OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View v,
                int position, long id) {

            // Sending image id to FullScreenActivity
            Intent i = new Intent(getApplicationContext(), ImageSelection.class);
            // passing array index
            i.putExtra("imageIndex_from_Activity", position);
            startActivity(i);

        }
    });

> ImageAdapter class

 private class ImageAdapter extends BaseAdapter {

    private Context context;

    public ImageAdapter(Context localContext) {
        context = localContext;
    }

    public int getCount() {
        return cursor.getCount();
    }
    public Object getItem(int position) {
        return position;
    }
    public long getItemId(int position) {
        return position;
    }
    public View getView(int position, View convertView, ViewGroup parent) {
        ImageView picturesView;
        if (convertView == null) {
            picturesView = new ImageView(context);
            // Move cursor to current position
            cursor.moveToPosition(position);
            // Get the current value for the requested column
            int imageID = cursor.getInt(columnIndex);
            // Set the content of the image based on the provided URI
            picturesView.setImageURI(Uri.withAppendedPath(
                    MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID));
            picturesView.setScaleType(ImageView.ScaleType.FIT_CENTER);
            picturesView.setPadding(5, 5, 5, 5);
            picturesView.setLayoutParams(new GridView.LayoutParams(80, 80));
        }
        else {
            picturesView = (ImageView)convertView;
        }
        return picturesView;
    }
}

Attaching screenshots, 1.Before Scrolling 2.Scrolled down and scrolled up again.

Why does the order changes??

解决方案

You're only setting the image on new views.

Do the following:

if (convertView == null) {
    picturesView = new ImageView(context);
    picturesView.setScaleType(ImageView.ScaleType.FIT_CENTER);
    picturesView.setPadding(5, 5, 5, 5);
    picturesView.setLayoutParams(new GridView.LayoutParams(80, 80));    
} else {
    picturesView = (ImageView)convertView;
}
// Move cursor to current position
cursor.moveToPosition(position);
// Get the current value for the requested column
int imageID = cursor.getInt(columnIndex);
// Set the content of the image based on the provided URI
picturesView.setImageURI(Uri.withAppendedPath(
MediaStore.Images.Thumbnails.EXTERNAL_CONTENT_URI, "" + imageID));

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