Question

我试图在Android Studio中创建一个应用程序，允许用户使用EditText并输入图像的URL，然后图像显示在imageview中

package com.example.michelle.imageurl;

import android.app.ProgressDialog;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.AsyncTask;
import android.app.Activity;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Button;
import android.widget.ImageView;
import android.widget.Toast;

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

public class Image extends Activity {

Button retrieveImage;
ImageView image;
String fileUrl, src;
Bitmap bitmap;
ProgressDialog pDialog;

/*Drawable loadImagefromNetwork(String url){

    try
    {
        InputStream is = (InputStream) new URL(url).getContent();
        Drawable d = Drawable.createFromStream(is, "src.name");
        return d;
    }
    catch(Exception e)
    {
        System.out.println("Exc=" + e);
        return null;
    }
}*/

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_image);

    retrieveImage = (Button)findViewById(R.id.retrieve);
    image = (ImageView)findViewById(R.id.imageView);
    loadImageFromURL();
    getBitmapFromURL(src);

    retrieveImage.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {

            new LoadImage().execute(fileUrl);
        }
    });
}

public Bitmap getBitmapFromURL(String src)
{
    try
    {
        java.net.URL url = new java.net.URL(src);
        HttpURLConnection connection = (HttpURLConnection) url.openConnection();
        connection.setDoInput(true);
        connection.connect();

        InputStream input = connection.getInputStream();
        Bitmap bitmap = BitmapFactory.decodeStream(input);
        return bitmap;
    } catch (MalformedURLException e) {
        e.printStackTrace();
        return null;
    } catch (IOException e) {
        e.printStackTrace();
        return null;
    }
}


private class LoadImage extends AsyncTask<String, String, Bitmap>
{
    @Override
    protected Bitmap doInBackground(String... args) {
        try {
            bitmap = BitmapFactory.decodeStream((InputStream)new URL(args[0]).getContent());

        } catch (Exception e) {
            e.printStackTrace();
        }
        return bitmap;
    }

    @Override
    protected void onPreExecute()
    {
        super.onPreExecute();
        pDialog = new ProgressDialog(Image.this);
        pDialog.setMessage("Loading Image...");
        pDialog.show();
    }
}

protected void onPostExecute(Bitmap image) {

    if(image != null){
        ImageView img = new ImageView(this);
        img.setImageBitmap(bitmap);
        pDialog.dismiss();
    }else{

        pDialog.dismiss();
        Toast.makeText(Image.this, "Image Does Not exist or Network Error",     Toast.LENGTH_SHORT).show();

    }
}
@Override
public boolean onCreateOptionsMenu(Menu menu) {
    // Inflate the menu; this adds items to the action bar if it is present.
    getMenuInflater().inflate(R.menu.menu_image, menu);
    return true;
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {
    // Handle action bar item clicks here. The action bar will
    // automatically handle clicks on the Home/Up button, so long
    // as you specify a parent activity in AndroidManifest.xml.
    int id = item.getItemId();

    //noinspection SimplifiableIfStatement
    if (id == R.id.action_settings) {
        return true;
    }

    return super.onOptionsItemSelected(item);
}

public boolean loadImageFromURL(){
    try {


        URL myFileUrl = new URL (fileUrl);
        HttpURLConnection conn =
                (HttpURLConnection) myFileUrl.openConnection();
        conn.setDoInput(true);
        conn.connect();

        InputStream is = conn.getInputStream();

        image.setImageBitmap(BitmapFactory.decodeStream(is));

        return true;

    } catch (MalformedURLException e) {
        e.printStackTrace();
    } catch (Exception e) {
        e.printStackTrace();
    }

    return false;
}
}

这是我的主要活动的代码，我在那里使用ImageView和位图以及尝试获取图像的所有内容但是当我运行应用程序时，我得到的是一个不变的弹出窗口只是说加载图像图像从未实际加载

这是活动xml文件

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
android:paddingBottom="@dimen/activity_vertical_margin"
tools:context=".Image">

<EditText
    android:layout_width= "150dp"
    android:layout_height="wrap_content"
    android:id="@+id/image"
    android:layout_marginTop="90dp"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true" />

<Button
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Retrieve Image"
    android:id="@+id/retrieve"
    android:layout_centerVertical="true"
    android:layout_centerHorizontal="true" />

<ImageView
    android:layout_width="100dp"
    android:layout_height="50dp"
    android:id="@+id/imageView"
    android:layout_below="@+id/imageView"
    android:layout_centerHorizontal="true" />
</LinearLayout>

非常感谢任何帮助

Answer 1

方法protected void onPostExecute(Bitmap image)需要在私有类LoadImage中。看起来你只是在内部类定义之外。

Answer 2

你可以使用Glide库。

retrieveImage = (Button) findViewById(R.id.retrieve);
imageView = (ImageView) findViewById(R.id.imageView);
final EditText editText = (EditText) findViewById(R.id.image);

retrieveImage.setOnClickListener(new View.OnClickListener() {
    @Override
    public void onClick(View v) {
        Glide.with(Main22Activity.this).load(editText.getText().toString()).into(imageView);
    }
});

添加这些依赖项

compile＆＃39; com.github.bumptech.glide：glide：3.6.1＆＃39;
编译＆＃39; com.android.support：support-v4：19.1.0＆＃39;

Glide Library

Answer 3

使用picasso library非常简单易用，非常适合您的任务

Picasso.with(context).load(EditText.getText().toString).into(imageView);

将库添加到build.gradle

compile 'com.squareup.picasso:picasso:2.5.2'

用户输入图像的URL并显示在imageview中

3 个答案: