从URL设置图像的ImageView与AsynchTask [英] Setting image from url to ImageView with AsynchTask

问题描述

我在我的网站上的图像，我想在我的ImageView设置。做我需要使用非同步任务。我做的象下面这样。但
新getThumbnail（）执行（stringThumbnail）; 抛出我的错误 getThumbnail不能被解析为一个类型。我是什么这里做错了吗？

 最后ImageView的缩略图=（ImageView的）findViewById（R.id.btnThumbnail）;
字符串stringThumbnail =myImage.jpg这个参数;
新getThumbnail（）执行（stringThumbnail）;        类getThumbnail扩展的AsyncTask＆LT;弦乐，太虚，太虚＆GT; {            保护无效doInBackground（字符串...数据）{
                串拇指=数据[0];
                尝试{
                  位图位图= BitmapFactory.de codeStream（（InputStream的）新的URL（http://mySite.com/images/+拇指）.getContent（））;                }赶上（MalformedURLException的E）{
                  e.printStackTrace（）;
                }赶上（IOException异常五）{
                  e.printStackTrace（）;
                }
                返回null;
            }            保护无效onPostExecute（位图图片）{
                // TODO：检查this.exception
                // TODO：做一些配合饲料
                thumbnail.setImageBitmap（IMG）;
            }
         }
 

解决方案

问题是在异步任务中使用它像这样

 公共类MainActivity延伸活动{    私人ImageView的mThumbnail;
    @覆盖
    保护无效的onCreate（捆绑savedInstanceState）{
        super.onCreate（savedInstanceState）;
        的setContentView（R.layout.activity_main）;
        mThumbnail =（ImageView的）findViewById（R.id.btnThumbnail）;
        字符串stringThumbnail =myImage.jpg这个参数;
        新getThumbnail（）执行（stringThumbnail）;    }    类getThumbnail扩展的AsyncTask＆LT;弦乐，太虚，位图＆GT; {        保护位图doInBackground（字符串...数据）{
            串拇指=数据[0];
            位图位图= NULL;
            尝试{
                Log.d（TEST，做背景）;
                位= BitmapFactory
                        由Matchi.com提供回到codeStream（（InputStream的新的网址
                                http://mySite.com/images/+拇指）
                                .getContent（））;            }赶上（MalformedURLException的E）{
                e.printStackTrace（）;
            }赶上（IOException异常五）{
                e.printStackTrace（）;
            }
            返回位图;
        }        保护无效onPostExecute（位图图片）{
            Log.d（TEST，后执行）;
            mThumbnail.setImageBitmap（IMG）;
        }
    }}
 

也确保btnThumbnail是ImageView的。 preFIX BTN混乱，也宣布允许

 ＆LT;使用许可权的android：NAME =android.permission.INTERNET对/＆GT;
 

在manifest.xml

I have an image on my website, that I want to set on my ImageView. Do to that I needed to use an asynch task. I'm doing it like below. But new getThumbnail().execute(stringThumbnail); is throwing me the error getThumbnail cannot be resolved to a type. What am I doing wrong in here?

final ImageView thumbnail = (ImageView) findViewById(R.id.btnThumbnail);
String stringThumbnail = "myImage.jpg";
new getThumbnail().execute(stringThumbnail);        

        class getThumbnail extends AsyncTask<String, Void, Void> {

            protected Void doInBackground(String... data) {
                String thumb = data[0];
                try {
                  Bitmap bitmap = BitmapFactory.decodeStream((InputStream)new URL("http://mySite.com/images/" + thumb).getContent());

                } catch (MalformedURLException e) {
                  e.printStackTrace();
                } catch (IOException e) {
                  e.printStackTrace();
                }
                return null;
            }

            protected void onPostExecute(Bitmap img) {
                // TODO: check this.exception 
                // TODO: do something with the feed
                thumbnail.setImageBitmap(img); 
            }
         }

解决方案

The problem is in async task use it like this

public class MainActivity extends Activity {

    private ImageView mThumbnail;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        mThumbnail = (ImageView) findViewById(R.id.btnThumbnail);
        String stringThumbnail = "myImage.jpg";
        new getThumbnail().execute(stringThumbnail);

    }

    class getThumbnail extends AsyncTask<String, Void, Bitmap> {

        protected Bitmap doInBackground(String... data) {
            String thumb = data[0];
            Bitmap bitmap = null;
            try {
                Log.d("TEST", "do in background");
                bitmap = BitmapFactory
                        .decodeStream((InputStream) new URL(
                                "http://mySite.com/images/" + thumb)
                                .getContent());

            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            }
            return bitmap;
        }

        protected void onPostExecute(Bitmap img) {
            Log.d("TEST", "post execute");
            mThumbnail.setImageBitmap(img);
        }
    }

}

also make sure that btnThumbnail is a imageView. Prefix btn is confusing and also declare the permission

<uses-permission android:name="android.permission.INTERNET"/>

in the manifest.xml

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