如何显示从mysql数据库获取的图像到imageview

Question

这是我必须设置成功登录用户图像的布局

并且我已将图像的 url 保存在 table 中，用户的所有详细信息都在那里....

所以我尝试的是从数据库中获取图像的 url，然后尝试将其设置到 imageview 中。我已经检查过 url 正在进入变量...

所以正如您在上图中看到的那样，它没有在 imageview 中设置图像，但是当我在定义变量时首先将 url 分配给 imgurl 变量然后它工作正常...

我不知道为什么会这样……我是不是做错了什么或者有其他方法可以做到这一点吗？

这是文件的代码...

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.Menu;
import android.view.View;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;

import com.android.volley.AuthFailureError;
import com.android.volley.Request;
import com.android.volley.RequestQueue;
import com.android.volley.Response;
import com.android.volley.VolleyError;
import com.android.volley.toolbox.StringRequest;
import com.android.volley.toolbox.Volley;

import java.io.IOException;
import java.io.InputStream;
import java.lang.reflect.Method;
import java.util.HashMap;
import java.util.Map;

public class Dashboard extends AppCompatActivity {
    TextView usrname;
    ImageView profileimg;
    public static String imgurl = "";//here

    /**
     * Shared Preferences
     **/
    SharedPreferences sharedPreferences;
    public static final String mypreference = "mypref";
    public static final String Name = "nameKey";
    public static final String Email = "emailKey";

    /**
     * Shared Preferences
     **/
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_dashboard);
        Toolbar toolbar = findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);
        getSupportActionBar().setDisplayShowTitleEnabled(false);

        profileimg = findViewById(R.id.iv_display_image);
        usrname = findViewById(R.id.tv_username);
        /**Shared Preferences**/
        sharedPreferences = getSharedPreferences(mypreference,
                Context.MODE_PRIVATE);

        /**Shared Preferences**/
        //fetching session data
        String name = sharedPreferences.getString(Name, "0");
        usrname.setText(name);
        fetchimg(name);
        LoadImage loadImage = new LoadImage(profileimg);
        Log.d("Oncreate img url", imgurl);
        loadImage.execute(imgurl);
    }

    private void fetchimg(String name) {

        StringRequest request = new StringRequest(Request.Method.POST, "https://**url**//fetchimg.php", new Response.Listener<String>() {

            @Override
            public void onResponse(String response) {
                if (response.startsWith("Here")) {
                    String urlstr = getUrl(response, "Here ");
                    seturl(urlstr);
                    Log.d("urlstr value:", urlstr);
                } else {
                    Toast.makeText(getApplicationContext(), response, Toast.LENGTH_SHORT).show();
                    Log.d("vOLLEY ERROR", response.toString());
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();
                Log.d("vOLLEY ERROR", error.getMessage().toString());
            }
        }
        ) {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> params = new HashMap<String, String>();
                params.put("login_name", "xxxxx");
                params.put("login_pass", "xxxxx");
                return params;
            }
        };

        RequestQueue requestQueue = Volley.newRequestQueue(Dashboard.this);
        requestQueue.add(request);
    }

    private void seturl(String urlstr) {
        this.imgurl = urlstr;
        Log.d("Image url set inside seturl", imgurl);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.dashboardmenu, menu);
        return true;
    }

    public void openeditprofile(View view) {
        startActivity(new Intent(this, EditProfileActivity.class));
    }

    private class LoadImage extends AsyncTask<String, Void, Bitmap> {
        ImageView imageView;

        public LoadImage(ImageView profileimg) {
            this.imageView = profileimg;
        }

        @Override
        protected Bitmap doInBackground(String... strings) {
            String urlLink = strings[0];
            Bitmap bitmap = null;
            try {
                InputStream inputStream = new java.net.URL(urlLink).openStream();
                bitmap = BitmapFactory.decodeStream(inputStream);
            } catch (IOException e) {
                e.printStackTrace();
            }
            return bitmap;
        }

        @Override
        protected void onPostExecute(Bitmap bitmap) {
            profileimg.setImageBitmap(bitmap);
        }
    }

    public static String getUrl(String string, String word) {

        // Check if the word is present in string
        // If found, remove it using removeAll()
        if (string.contains(word)) {

            // To cover the case
            // if the word is at the
            // beginning of the string
            // or anywhere in the middle
            String tempWord = word + " ";
            string = string.replaceAll(tempWord, "");

            // To cover the edge case
            // if the word is at the
            // end of the string
            tempWord = " " + word;
            string = string.replaceAll(tempWord, "");
        }

        // Return the resultant string
        return string;
    }
}

Answer 1

您正在异步获取图像，您的 Asynctask 执行将使用空 imgUrl 调用，因为它尚未获取，将 AsyncTask 执行代码移至 onResponse 的获取

private void fetchimg(String name) {

        StringRequest request = new StringRequest(Request.Method.POST, "https://**url**//fetchimg.php", new Response.Listener<String>() {

            @Override
            public void onResponse(String response) {
                if (response.startsWith("Here")) {
                    String urlstr = getUrl(response, "Here ");
                    seturl(urlstr);
       

                   //here the url is ready to consume
                    Log.d("urlstr value:", urlstr);
                    //load the image now
                    LoadImage loadImage = new LoadImage(profileimg);
                    Log.d("Oncreate img url", imgurl);
                    loadImage.execute(imgurl);
                } else {
                    Toast.makeText(getApplicationContext(), response, Toast.LENGTH_SHORT).show();
                    Log.d("vOLLEY ERROR", response.toString());
                }
            }
        }, new Response.ErrorListener() {
            @Override
            public void onErrorResponse(VolleyError error) {
                Toast.makeText(getApplicationContext(), error.getMessage(), Toast.LENGTH_SHORT).show();
                Log.d("vOLLEY ERROR", error.getMessage().toString());
            }
        }
        ) {
            @Override
            protected Map<String, String> getParams() throws AuthFailureError {
                Map<String, String> params = new HashMap<String, String>();
                params.put("login_name", "xxxxx");
                params.put("login_pass", "xxxxx");
                return params;
            }
        };

        RequestQueue requestQueue = Volley.newRequestQueue(Dashboard.this);
        requestQueue.add(request);
    }

Answer 2

use **Glide** to display Image from Url into image view.

You have to add glide lib in app-level build.gradle file.

implementation 'com.github.bumptech.glide:glide:4.12.0'
annotationProcessor 'com.github.bumptech.glide:compiler:4.12.0'

        Glide.with(this).load(url)
        .transform(CenterCrop(), RoundedCorners(radius))
        .placeholder(R.drawable.drawable_image_placeholder)
        .error(R.drawable.drawable_image_placeholder)
        .into(ivProfile)

drawable_image_placeholder is the default imageview that displays
when getting the error to load the image. ivProfile is imageview .

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