1. 技术文章
  2. Android - Set ImageView to URL

Android - Set ImageView to URL

由 允我心安 提交于 2019-11-28 07:52:58

You should not do network related operation on the main ui thread.

You can findViewById of the current view hierachy set to the activity. check if you have imageview in ivget.xml. Also use a asynctask as below and make a http get request to get the image.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
        android:id="@+id/imageView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentTop="true"
        android:layout_centerHorizontal="true"
        android:layout_marginTop="173dp"
        android:src="@drawable/ic_launcher" />

</RelativeLayout>

MainActivity.java

    public class AndroidCustomGalleryActivity extends Activity { 
ImageView iv;
Bitmap image ;
ProgressDialog pd;
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    iv = (ImageView) findViewById(R.id.imageView1);
    pd = new ProgressDialog(this);
    pd.setMessage("Loading..");
    new TheTask().execute();    
}
class TheTask extends AsyncTask<Void,Void,Void>
{

    @Override
    protected void onPreExecute() {
        // TODO Auto-generated method stub
        super.onPreExecute();
        pd.show();
    }


    @Override
    protected Void doInBackground(Void... params) {
        // TODO Auto-generated method stub
        try
        {
        //URL url = new URL( "http://a3.twimg.com/profile_images/670625317/aam-logo-v3-twitter.png");


        image = downloadBitmap("http://a3.twimg.com/profile_images/670625317/aam-logo-v3-twitter.png");
        }
        catch(Exception e)
        {
            e.printStackTrace();
        }
        return null;
    }

    @Override
    protected void onPostExecute(Void result) {
        // TODO Auto-generated method stub
        super.onPostExecute(result);
        pd.dismiss();
        if(image!=null)
        {
            iv.setImageBitmap(image);
        }

    }   
}
 private Bitmap downloadBitmap(String url) {
     // initilize the default HTTP client object
     final DefaultHttpClient client = new DefaultHttpClient();

     //forming a HttoGet request 
     final HttpGet getRequest = new HttpGet(url);
     try {

         HttpResponse response = client.execute(getRequest);

         //check 200 OK for success
         final int statusCode = response.getStatusLine().getStatusCode();

         if (statusCode != HttpStatus.SC_OK) {
             Log.w("ImageDownloader", "Error " + statusCode + 
                     " while retrieving bitmap from " + url);
             return null;

         }

         final HttpEntity entity = response.getEntity();
         if (entity != null) {
             InputStream inputStream = null;
             try {
                 // getting contents from the stream 
                 inputStream = entity.getContent();

                 // decoding stream data back into image Bitmap that android understands
                 image = BitmapFactory.decodeStream(inputStream);


             } finally {
                 if (inputStream != null) {
                     inputStream.close();
                 }
                 entity.consumeContent();
             }
         }
     } catch (Exception e) {
         // You Could provide a more explicit error message for IOException
         getRequest.abort();
         Log.e("ImageDownloader", "Something went wrong while" +
                 " retrieving bitmap from " + url + e.toString());
     } 

     return image;
 }
}


android.app.Activity.findViewById(Activity.java:1794)

=> It says you haven't initialized your ImageView i.e. "i" in your code.

ImageView i = (ImageView) findViewById(R.id.myImageViewInXML);

Use Glide

Implementation 'com.github.bumptech.glide:glide:4.2.0'

Or

in java 

Glide.with(getApplicationContext())
                .load(image)
                .into(imageView);
标签
java
android
url
bitmap
imageview
易学教程内所有资源均来自网络或用户发布的内容，如有违反法律规定的内容欢迎反馈！
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!