從 url 加載圖片

Question

我有一個圖片網址。 我想在 ImageView 中顯示來自這個 URL 的圖像，但我無法做到這一點。

如何做到這一點？

Answer 1

如果您基於按鈕單擊加載圖像，上面接受的答案非常好，但是如果您在新活動中執行此操作，它會凍結 UI 一兩秒鍾。 環顧四周，我發現一個簡單的 asynctask 消除了這個問題。

要在活動結束時使用 asynctask 添加此類：

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

  public DownloadImageTask(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);
  }
}

並使用您的 onCreate() 方法調用：

new DownloadImageTask((ImageView) findViewById(R.id.imageView1))
        .execute(MY_URL_STRING);

不要忘記在清單文件中添加以下權限

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

對我很有用。 :)

Answer 2

URL url = new URL("http://image10.bizrate-images.com/resize?sq=60&uid=2216744464");
Bitmap bmp = BitmapFactory.decodeStream(url.openConnection().getInputStream());
imageView.setImageBitmap(bmp);

Answer 3

嘗試picasso ，並在一個聲明中完成

Picasso.with(context)
                .load(ImageURL)
                .resize(width,height).into(imageView);

教程： https ://youtu.be/DxRqxsEPc2s

（注意： Picasso.with() Picasso.get() ）

Answer 4

有兩種方法：

1) 使用 Glide 庫這是從 url 加載圖像的最佳方式，因為當您第二次嘗試顯示相同的 url 時，它將從緩存中顯示，從而提高應用程序性能

Glide.with(context).load("YourUrl").into(imageView);

依賴： implementation 'com.github.bumptech.glide:glide:4.10.0'

2）使用流。 在這里，您要從 url 圖像創建位圖

URL url = new URL("YourUrl");
Bitmap bitmap = BitmapFactory.decodeStream(url.openConnection().getInputStream());
imageView.setImageBitmap(bitmap);

Answer 5

試試這個添加畢加索lib jar文件

Picasso.with(context)
                .load(ImageURL)
                .resize(width,height).noFade().into(imageView);

Answer 6

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;
import android.widget.Toast;

public class imageDownload {

    Bitmap bmImg;
    void downloadfile(String fileurl,ImageView img)
    {
        URL myfileurl =null;
        try
        {
            myfileurl= new URL(fileurl);

        }
        catch (MalformedURLException e)
        {

            e.printStackTrace();
        }

        try
        {
            HttpURLConnection conn= (HttpURLConnection)myfileurl.openConnection();
            conn.setDoInput(true);
            conn.connect();
            int length = conn.getContentLength();
            int[] bitmapData =new int[length];
            byte[] bitmapData2 =new byte[length];
            InputStream is = conn.getInputStream();
            BitmapFactory.Options options = new BitmapFactory.Options();

            bmImg = BitmapFactory.decodeStream(is,null,options);

            img.setImageBitmap(bmImg);

            //dialog.dismiss();
            } 
        catch(IOException e)
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
//          Toast.makeText(PhotoRating.this, "Connection Problem. Try Again.", Toast.LENGTH_SHORT).show();
        }


    }


}

在您的活動中獲取 imageview 並設置資源 imageDownload(url,yourImageview);

Answer 7

UrlImageViewHelper 將使用在 URL 中找到的圖像填充 ImageView。 UrlImageViewHelper 將自動下載、保存和緩存 BitmapDrawables 中的所有圖像 url。 重復的 url 不會被加載到內存中兩次。 位圖內存使用弱引用哈希表進行管理，因此一旦您不再使用圖像，它將自動被垃圾收集。

UrlImageViewHelper.setUrlDrawable(imageView, "http://example.com/image.png");

https://github.com/koush/UrlImageViewHelper

Answer 8

基於這個答案，我編寫了自己的加載器。

帶有加載效果和外觀效果：

import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.util.DisplayMetrics;
import android.util.Log;
import android.view.Gravity;
import android.view.View;
import android.view.ViewGroup;
import android.view.animation.AlphaAnimation;
import android.view.animation.Animation;
import android.widget.FrameLayout;
import android.widget.ImageView;
import android.widget.ProgressBar;

import java.io.InputStream;

/**
 * Created by Sergey Shustikov (pandarium.shustikov@gmail.com) at 2015.
 */
public class DownloadImageTask extends AsyncTask<String, Void, Bitmap>
{
    public static final int ANIMATION_DURATION = 250;
    private final ImageView mDestination, mFakeForError;
    private final String mUrl;
    private final ProgressBar mProgressBar;
    private Animation.AnimationListener mOutAnimationListener = new Animation.AnimationListener()
    {
        @Override
        public void onAnimationStart(Animation animation)
        {

        }

        @Override
        public void onAnimationEnd(Animation animation)
        {
            mProgressBar.setVisibility(View.GONE);
        }

        @Override
        public void onAnimationRepeat(Animation animation)
        {

        }
    };
    private Animation.AnimationListener mInAnimationListener = new Animation.AnimationListener()
    {
        @Override
        public void onAnimationStart(Animation animation)
        {
            if (isBitmapSet)
                mDestination.setVisibility(View.VISIBLE);
            else
                mFakeForError.setVisibility(View.VISIBLE);
        }

        @Override
        public void onAnimationEnd(Animation animation)
        {

        }

        @Override
        public void onAnimationRepeat(Animation animation)
        {

        }
    };
    private boolean isBitmapSet;

    public DownloadImageTask(Context context, ImageView destination, String url)
    {
        mDestination = destination;
        mUrl = url;
        ViewGroup parent = (ViewGroup) destination.getParent();
        mFakeForError = new ImageView(context);
        destination.setVisibility(View.GONE);
        FrameLayout layout = new FrameLayout(context);
        mProgressBar = new ProgressBar(context);
        FrameLayout.LayoutParams params = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        params.gravity = Gravity.CENTER;
        mProgressBar.setLayoutParams(params);
        FrameLayout.LayoutParams copy = new FrameLayout.LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);
        copy.gravity = Gravity.CENTER;
        copy.width = dpToPx(48);
        copy.height = dpToPx(48);
        mFakeForError.setLayoutParams(copy);
        mFakeForError.setVisibility(View.GONE);
        mFakeForError.setImageResource(android.R.drawable.ic_menu_close_clear_cancel);
        layout.addView(mProgressBar);
        layout.addView(mFakeForError);
        mProgressBar.setIndeterminate(true);
        parent.addView(layout, new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MATCH_PARENT, ViewGroup.LayoutParams.MATCH_PARENT));
    }

    protected Bitmap doInBackground(String... urls)
    {
        String urlDisplay = mUrl;
        Bitmap bitmap = null;
        try {
            InputStream in = new java.net.URL(urlDisplay).openStream();
            bitmap = BitmapFactory.decodeStream(in);
        } catch (Exception e) {
            Log.e("Error", e.getMessage());
            e.printStackTrace();
        }
        return bitmap;
    }

    protected void onPostExecute(Bitmap result)
    {
        AlphaAnimation in = new AlphaAnimation(0f, 1f);
        AlphaAnimation out = new AlphaAnimation(1f, 0f);
        in.setDuration(ANIMATION_DURATION * 2);
        out.setDuration(ANIMATION_DURATION);
        out.setAnimationListener(mOutAnimationListener);
        in.setAnimationListener(mInAnimationListener);
        in.setStartOffset(ANIMATION_DURATION);
        if (result != null) {
            mDestination.setImageBitmap(result);
            isBitmapSet = true;
            mDestination.startAnimation(in);
        } else {
            mFakeForError.startAnimation(in);
        }
        mProgressBar.startAnimation(out);
    }
    public int dpToPx(int dp) {
        DisplayMetrics displayMetrics = mDestination.getContext().getResources().getDisplayMetrics();
        int px = Math.round(dp * (displayMetrics.xdpi / DisplayMetrics.DENSITY_DEFAULT));
        return px;
    }
}

添加權限

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

並執行：

 new DownloadImageTask(context, imageViewToLoad, urlToImage).execute();

Answer 9

在清單中添加 Internet 權限

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

比創建方法如下，

 public static Bitmap getBitmapFromURL(String src) {
    try {
        Log.e("src", src);
        URL url = new URL(src);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setDoInput(true);
        connection.connect();
        InputStream input = connection.getInputStream();
        Bitmap myBitmap = BitmapFactory.decodeStream(input);
        Log.e("Bitmap", "returned");
        return myBitmap;
    } catch (IOException e) {
        e.printStackTrace();
        Log.e("Exception", e.getMessage());
        return null;
    }
}

現在將其添加到您的 onCreate 方法中，

 ImageView img_add = (ImageView) findViewById(R.id.img_add);


img_add.setImageBitmap(getBitmapFromURL("http://www.deepanelango.me/wpcontent/uploads/2017/06/noyyal1.jpg"));

這對我有用。

Answer 10

這是從 URL 顯示圖像的示例代碼。

public static Void downloadfile(String fileurl, ImageView img) {
        Bitmap bmImg = null;
        URL myfileurl = null;
        try {
            myfileurl = new URL(fileurl);
        } catch (MalformedURLException e) {
            e.printStackTrace();
        }
        try {
            HttpURLConnection conn = (HttpURLConnection) myfileurl.openConnection();
            conn.setDoInput(true);
            conn.connect();
            int length = conn.getContentLength();
            if (length > 0) {
                int[] bitmapData = new int[length];
                byte[] bitmapData2 = new byte[length];
                InputStream is = conn.getInputStream();
                bmImg = BitmapFactory.decodeStream(is);
                img.setImageBitmap(bmImg);
            }

        } catch (IOException e) {
            e.printStackTrace();
        }
    }

Answer 11

我嘗試過的最佳方法，而不是使用任何庫

public Bitmap getbmpfromURL(String surl){
    try {
        URL url = new URL(surl);
        HttpURLConnection urlcon = (HttpURLConnection) url.openConnection();
        urlcon.setDoInput(true);
        urlcon.connect();
        InputStream in = urlcon.getInputStream();
        Bitmap mIcon = BitmapFactory.decodeStream(in);
        return  mIcon;
    } catch (Exception e) {
        Log.e("Error", e.getMessage());
        e.printStackTrace();
        return null;
    }
}

Answer 12

public class MainActivity extends Activity {

    Bitmap b;
    ImageView img;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        img = (ImageView)findViewById(R.id.imageView1);
        information info = new information();
        info.execute("");
    }

    public class information extends AsyncTask<String, String, String>
    {
        @Override
        protected String doInBackground(String... arg0) {

            try
            {
                URL url = new URL("http://10.119.120.10:80/img.jpg");
                InputStream is = new BufferedInputStream(url.openStream());
                b = BitmapFactory.decodeStream(is);

            } catch(Exception e){}
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            img.setImageBitmap(b);
        }
    }
}

Answer 13

下面的代碼向您展示了如何使用 RxAndroid 從 url 字符串設置 ImageView。 一、添加RxAndroid庫2.0

dependencies {
    // RxAndroid
    compile 'io.reactivex.rxjava2:rxandroid:2.0.0'
    compile 'io.reactivex.rxjava2:rxjava:2.0.0'

    // Utilities
    compile 'org.apache.commons:commons-lang3:3.5'

}

現在使用 setImageFromUrl 設置圖像。

public void setImageFromUrl(final ImageView imageView, final String urlString) {

    Observable.just(urlString)
        .filter(new Predicate<String>() {
            @Override public boolean test(String url) throws Exception {
                return StringUtils.isNotBlank(url);
            }
        })
        .map(new Function<String, Drawable>() {
            @Override public Drawable apply(String s) throws Exception {
                URL url = null;
                try {
                    url = new URL(s);
                    return Drawable.createFromStream((InputStream) url.getContent(), "profile");
                } catch (final IOException ex) {
                    return null;
                }
            }
        })
        .filter(new Predicate<Drawable>() {
            @Override public boolean test(Drawable drawable) throws Exception {
                return drawable != null;
            }
        })
        .subscribeOn(Schedulers.io())
        .observeOn(AndroidSchedulers.mainThread())
        .subscribe(new Consumer<Drawable>() {
            @Override public void accept(Drawable drawable) throws Exception {
                imageView.setImageDrawable(drawable);
            }
        });
}

Answer 14

loadImage("http://relinjose.com/directory/filename.png");

干得好

void loadImage(String image_location) {
    URL imageURL = null;
    if (image_location != null) {
        try {
            imageURL = new URL(image_location);         
            HttpURLConnection connection = (HttpURLConnection) imageURL
                    .openConnection();
            connection.setDoInput(true);
            connection.connect();
            InputStream inputStream = connection.getInputStream();
            bitmap = BitmapFactory.decodeStream(inputStream);// Convert to bitmap
            ivdpfirst.setImageBitmap(bitmap);
        } catch (IOException e) {
            e.printStackTrace();
        }
    } else {
        //set any default
    }
}

Answer 15

嘗試這個：

InputStream input = contentResolver.openInputStream(httpuri);
Bitmap b = BitmapFactory.decodeStream(input, null, options);

Answer 16

對我來說， Fresco是其他圖書館中最好的。

只需設置Fresco，然后像這樣簡單地設置 imageURI：

draweeView.setImageURI(uri);

查看這個解釋 Fresco 的一些好處的答案。

Answer 17

這是我使用 Adrian 的代碼示例的工作解決方案：

private void loadImage(String pUrl) {
    Thread imageDataThread = new Thread(() -> {
        try {
            URL tUrl = new URL(pUrl);
            Bitmap imageBitmap = BitmapFactory.decodeStream(tUrl.openConnection().getInputStream());
            runOnUiThread(() -> image_preview.setImageBitmap(imageBitmap));
        } catch(IOException pExc) {
            showToast("Error loading image for this question!");
            pExc.printStackTrace();
        }
    });
    imageDataThread.start();
}

注意：您可以使用此預定義的方法來加載圖像位圖，也可以在需要調整圖像大小或對圖像進行一些類似操作時使用您的方法。