浏览查看图片

最新推荐文章于 2023-11-10 00:14:41 发布

原创最新推荐文章于 2023-11-10 00:14:41 发布 · 236 阅读

0 ·

CC 4.0 BY-SA版权

本文介绍了一个简单的Android应用程序，用于从互联网加载并显示图片。通过输入图片URL，应用会在后台线程下载图片，并在主线程中更新UI显示。文章提供了完整的代码实现，包括使用Handler进行消息传递来更新UI的方法。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

图片：

<img src="https://img-blog.youkuaiyun.com/20150703063458189?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvd29kZWRvbmd0aWFuMTk5NA==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/Center" alt="" />

package com.example.internetimageview;
import java.io.IOException;
import java.io.InputStream;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;
import android.app.Activity;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.os.Bundle;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.text.TextUtils;
import android.view.Menu;
import android.view.View;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends Activity {
    private EditText etImageUrl;
    private ImageView ivImage;
    public static final int SHOWIMAGE=1;
    private Handler handler=new Handler(){
    	public void handleMessage(android.os.Message msg) {
    		switch (msg.what) {
			case SHOWIMAGE:
				Bitmap bitmap=(Bitmap) msg.obj;
				ivImage.setImageBitmap(bitmap);
				break;
			default:
				break;
			}
    	};
    };
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.activity_main);
		initViews();
	}
	private void initViews() {
	   etImageUrl=(EditText) findViewById(R.id.etImageUrl);
	   ivImage=(ImageView) findViewById(R.id.ivImage);
	}
	@Override
	public boolean onCreateOptionsMenu(Menu menu) {
		// Inflate the menu; this adds items to the action bar if it is present.
		getMenuInflater().inflate(R.menu.main, menu);
		return true;
	}
	public void viewImage(View view){
		final String imageUrl=etImageUrl.getText().toString();
		if(TextUtils.isEmpty(imageUrl)){
			Toast.makeText(getApplicationContext(),"图片路径不能为空",Toast.LENGTH_LONG).show();
		}else{
			new Thread(){
		
					public void run() {
						try {
							URL url=new URL(imageUrl);
							HttpURLConnection httpURLConnection=(HttpURLConnection) url.openConnection();
						    httpURLConnection.setRequestMethod("GET");
						    httpURLConnection.setConnectTimeout(5000);
						    int responseCode=httpURLConnection.getResponseCode();
						    if(responseCode==200){
						    	InputStream inputStream=httpURLConnection.getInputStream();
						    	Bitmap bitmap=BitmapFactory.decodeStream(inputStream);
						    	Message message=new Message();
						    	message.what=SHOWIMAGE;
						    	message.obj=bitmap;
						    	//ivImage.setImageBitmap(bitmap);
						    	handler.sendMessage(message);

						    }else{
						    	Looper.prepare();
						    	Toast.makeText(MainActivity.this,"显示图片失败",Toast.LENGTH_LONG).show();
						    	Looper.loop();
						    }
						} catch (MalformedURLException e) {
							e.printStackTrace();
						} catch (IOException e) {
							e.printStackTrace();
						}
				}
			}.start();
			
		}
	}

}

<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"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context=".MainActivity" >
    <ImageView
        android:id="@+id/ivImage"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:layout_weight="1" />
    <EditText
        android:id="@+id/etImageUrl"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10"
        android:hint="请输入图片的地址"
        android:text="http://www.2cto.com/uploadfile/Collfiles/20141201/2014120109192831.png" />
    <Button
        android:id="@+id/btnView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center"
        android:background="@drawable/button_bg"
        android:onClick="viewImage"
        android:text="浏览" />
</LinearLayout>