java - 根据真/假条件从 URL 绘制位图

Question

使用以下代码，我只想在 chatMessageObj.left 为 true 时显示图像，但图像却显示不出来。

public View getView(int position, View convertView, ViewGroup parent) {

...

String personPhotoUrl = "Image url";
personPhotoUrl = personPhotoUrl.substring(0, personPhotoUrl.length() - 2) + PROFILE_PIC_SIZE;
    if (chatMessageObj.left) {
        new LoadProfileImage(chatImage).execute(personPhotoUrl);
    }

...

}

private class LoadProfileImage extends AsyncTask<String, Void, Bitmap> {
    ImageView bmImage;

    public LoadProfileImage(ImageView bmImage) {
        this.bmImage = bmImage;
    }

    protected Bitmap doInBackground(String... urls) {
        String urldisplay = urls[0];
        Bitmap mIcon11 = null;
        try {
            InputStream in = new java.net.URL(urldisplay).openStream();
            mIcon11 = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return mIcon11;
    }
    protected void onPostExecute(Bitmap result) {
        bmImage.setImageBitmap(result);
    }
}

我需要这样的东西:

protected void onPostExecute(Bitmap result, boolean display) {
    bmImage.setImageBitmap(display ? result : null);
}

谢谢。

Answer 1

这是因为listview总是保持刷新，所以你需要做的就是添加else block ，

类似这样的事情，

if (chatMessageObj.left) {
    new LoadProfileImage(chatImage).execute(personPhotoUrl);
} else {
    chatImage.setVisibility(View.GONE);
}

希望这对您有帮助:)