Android：从web URL加载图像

可能重复：

我正在开发一个应用程序，其中我有一个列表，其中每一行都有一个图像

此图像是从web URL加载的

下面是我的代码

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

    <ImageView
            android:id="@+id/list_row_img"
            android:layout_width="200dp"
            android:layout_height="200dp"
            />

    <TextView
            android:id="@+id/list_row_description"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            />

</LinearLayout>

当我跑步时，我在设备上什么也没有得到。只有灰色屏幕，没有异常发生

请注意，我在清单文件中添加了此权限

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

---

有人能帮我吗？

您的图像链接无效。尝试使用浏览器访问它，您会发现。这是你的问题。

试试这个

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.os.Bundle;
import android.os.StrictMode;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class MainActivity extends Activity {

    ImageView mImgView1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);

        mImgView1 = (ImageView) findViewById(R.id.mImgView1);
        String url = "https://www.morroccomethod.com/components/com_virtuemart/shop_image/category/resized/Trial_Sizes_4e4ac3b0d3491_175x175.jpg";
        BitmapFactory.Options bmOptions;
        bmOptions = new BitmapFactory.Options();
        bmOptions.inSampleSize = 1;
        Bitmap bm = loadBitmap(url, bmOptions);
        mImgView1.setImageBitmap(bm);
    }

    public static Bitmap loadBitmap(String URL, BitmapFactory.Options options) {
        Bitmap bitmap = null;
        InputStream in = null;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in, null, options);
            in.close();
        } catch (IOException e1) {
        }
        return bitmap;
    }

    private static InputStream OpenHttpConnection(String strURL)
            throws IOException {
        InputStream inputStream = null;
        URL url = new URL(strURL);
        URLConnection conn = url.openConnection();

        try {
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setRequestMethod("GET");
            httpConn.connect();

            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                inputStream = httpConn.getInputStream();
            }
        } catch (Exception ex) {
        }
        return inputStream;
    }
}

你可以通过

      new DownloadImageTask((ImageView)  im1).execute(url here);

---

私有类下载ImageTask扩展异步任务{
图像视图bmImage；
公共下载ImageTask（ImageView bmImage）{
this.bmImage=bmImage；
}
受保护位图doInBackground（字符串…URL）{
字符串urldisplay=url[0]；
位图mIcon11=null；
试一试{
InputStream in=newjava.net.URL（urldisplay.openStream（）；
mIcon11=BitmapFactory.decodeStream（in）；
}捕获（例外e）{
Log.e（“Error”，e.getMessage（））；
e、 printStackTrace（）；
}
返回mIcon11；
}
/*@覆盖
受保护的void onPreExecute（）{
//TODO自动生成的方法存根
super.onPreExecute（）；
showProgressDialog（）；
}*/
受保护的void onPostExecute（位图结果）{
//pDlg.discouse（）；
bmImage.setImageBitmap（结果）；
}}

使用下面的代码从url下载图像并将图像显示到imageview中，这将解决您的问题

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.os.Bundle;
import android.os.StrictMode;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class MainActivity extends Activity {

    ImageView mImgView1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);

        mImgView1 = (ImageView) findViewById(R.id.mImgView1);
        String url = "https://www.morroccomethod.com/components/com_virtuemart/shop_image/category/resized/Trial_Sizes_4e4ac3b0d3491_175x175.jpg";
        BitmapFactory.Options bmOptions;
        bmOptions = new BitmapFactory.Options();
        bmOptions.inSampleSize = 1;
        Bitmap bm = loadBitmap(url, bmOptions);
        mImgView1.setImageBitmap(bm);
    }

    public static Bitmap loadBitmap(String URL, BitmapFactory.Options options) {
        Bitmap bitmap = null;
        InputStream in = null;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in, null, options);
            in.close();
        } catch (IOException e1) {
        }
        return bitmap;
    }

    private static InputStream OpenHttpConnection(String strURL)
            throws IOException {
        InputStream inputStream = null;
        URL url = new URL(strURL);
        URLConnection conn = url.openConnection();

        try {
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setRequestMethod("GET");
            httpConn.connect();

            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                inputStream = httpConn.getInputStream();
            }
        } catch (Exception ex) {
        }
        return inputStream;
    }
}

---

+1对于实际检查链接@Gautam K@Lazy Ninja，链接有效加载一个图像“尽管它没有标记图像，但它是一个图像”链接正在工作。你有没有遇到过什么问题@懒惰？是的，有个问题。用此更改url并检查您的链接是否也无效。我确信URL不是问题所在。加载图像或获取URL内容时出错谢谢您的帮助。我有个问题。OpenHttpConnection（URL）此行出错是否有需要导入的API或库？@RanaOsama否，不需要导入任何API或库。@RanaOsama请查看我对导入包的更新回答。我收到以下错误：未为MainActivity类型定义OpenHttpConnection（String）方法尽管这样做有效，我建议您在从服务器下载时使用AsyncTask。绕过StrictMode.ThreadPolicy不是一个好主意。@Rana Osama尝试了这段代码？？？还没有，但现在可以用了。。。非常感谢你的帮助我用过了。它工作得很好！谢谢。简短而漂亮的回答。非常感谢你！正是我要找的！

import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.URL;
import java.net.URLConnection;
import android.os.Bundle;
import android.os.StrictMode;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.widget.ImageView;

public class MainActivity extends Activity {

    ImageView mImgView1;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
                .permitAll().build();
        StrictMode.setThreadPolicy(policy);

        mImgView1 = (ImageView) findViewById(R.id.mImgView1);
        String url = "https://www.morroccomethod.com/components/com_virtuemart/shop_image/category/resized/Trial_Sizes_4e4ac3b0d3491_175x175.jpg";
        BitmapFactory.Options bmOptions;
        bmOptions = new BitmapFactory.Options();
        bmOptions.inSampleSize = 1;
        Bitmap bm = loadBitmap(url, bmOptions);
        mImgView1.setImageBitmap(bm);
    }

    public static Bitmap loadBitmap(String URL, BitmapFactory.Options options) {
        Bitmap bitmap = null;
        InputStream in = null;
        try {
            in = OpenHttpConnection(URL);
            bitmap = BitmapFactory.decodeStream(in, null, options);
            in.close();
        } catch (IOException e1) {
        }
        return bitmap;
    }

    private static InputStream OpenHttpConnection(String strURL)
            throws IOException {
        InputStream inputStream = null;
        URL url = new URL(strURL);
        URLConnection conn = url.openConnection();

        try {
            HttpURLConnection httpConn = (HttpURLConnection) conn;
            httpConn.setRequestMethod("GET");
            httpConn.connect();

            if (httpConn.getResponseCode() == HttpURLConnection.HTTP_OK) {
                inputStream = httpConn.getInputStream();
            }
        } catch (Exception ex) {
        }
        return inputStream;
    }
}