Android使用webView长按保存下载网络图片

本文实例为大家分享了Android使用webView长按保存下载网络图片的具体代码，供大家参考，具体内容如下

最近发现在webView的setOnLongClickListener中可以获取到WebView.HitTestResult，根据获取的HitTestResult的Type来判断做不同的处理。通过判断Type的类型获取点击图片的url，然后把图片下载到本地，发送广播通知系统图库进行更新，在系统图库中查看下载的图片。运行Demo在网页中对图片做长按点击即可下载网络图片

直接上代码：

下面附有Demo下载：点击打开链接

package demo.sam.webview_demo; 

import android.app.Activity;
import android.app.Dialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.net.Uri;
import android.os.Handler;
import android.os.Message;
import android.provider.MediaStore;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.text.Editable;
import android.util.Log;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebChromeClient;
import android.webkit.WebResourceRequest;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ProgressBar;
import android.widget.Toast; 

import java.io.FileNotFoundException; 

public class MainActivity extends Activity { 

 private ProgressBar progress;
 private WebView webView;
 private EditText editText;
 private Button click;
 private Context context; 

 @Override
 protected void onCreate(Bundle savedInstanceState) {
  super.onCreate(savedInstanceState);
  setContentView(R.layout.activity_main);
  context= this;
  initView();
  initData();
  initListener(); 

 } 

 private void initData() {
  WebSettings settings = webView.getSettings();
  settings.setJavaScriptEnabled(true);
  settings.setUseWideViewPort(true);//设置此属性，可任意比例缩放
  settings.setLoadWithOverviewMode(true);
  // 使页面支持缩放
  settings.setBuiltInZoomControls(true);
  settings.setSupportZoom(true);
  //支持自动加载图片
  settings.setLoadsImagesAutomatically(true);
  settings.setLayoutAlgorithm(WebSettings.LayoutAlgorithm.NORMAL);// 排版适应屏幕
  // 缩放按钮
  settings.setDisplayZoomControls(false); 

  webView.setWebViewClient(new WebViewClient(){ 

   // 页面在当前页面跳转
   @Override
   public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {
    return super.shouldOverrideUrlLoading(view, request);
   } 

   // 页面加载结束
   @Override
   public void onPageFinished(WebView view, String url) {
    super.onPageFinished(view, url);
    if(progress!=null){
     progress.setVisibility(View.GONE);
    }
   }
  }); 

 } 

 private void initView() {
  progress = (ProgressBar) findViewById(R.id.progress);
  webView = (WebView) findViewById(R.id.webView);
  editText = (EditText) findViewById(R.id.url);
  click = (Button) findViewById(R.id.click);
 } 

 private void initListener() {
  // 网页加载进度显示
  webView.setWebChromeClient(new WebChromeClient(){
   @Override
   public void onProgressChanged(WebView view, int newProgress) {
    super.onProgressChanged(view, newProgress);
    progress.setVisibility(View.VISIBLE);
    progress.setProgress(newProgress);
   }
  }); 

  click.setOnClickListener(new View.OnClickListener() {
   @Override
   public void onClick(View view) {
    Log.e("输入的网站",editText.getText().toString().trim());
    webView.loadUrl(editText.getText().toString().trim());
   }
  }); 

  // 长按点击事件
  webView.setOnLongClickListener(new View.OnLongClickListener() {
   @Override
   public boolean onLongClick(View view) {
    final WebView.HitTestResult hitTestResult = webView.getHitTestResult();
    // 如果是图片类型或者是带有图片链接的类型
    if(hitTestResult.getType()== WebView.HitTestResult.IMAGE_TYPE||
      hitTestResult.getType()== WebView.HitTestResult.SRC_IMAGE_ANCHOR_TYPE){
     // 弹出保存图片的对话框
     AlertDialog.Builder builder = new AlertDialog.Builder(context);
     builder.setTitle("提示");
     builder.setMessage("保存图片到本地");
     builder.setPositiveButton("确认", new DialogInterface.OnClickListener() {
      @Override
      public void onClick(DialogInterface dialogInterface, int i) {
       String url = hitTestResult.getExtra();
       // 下载图片到本地
       DownPicUtil.downPic(url, new DownPicUtil.DownFinishListener(){ 

        @Override
        public void getDownPath(String s) {
         Toast.makeText(context,"下载完成",Toast.LENGTH_LONG).show();
         Message msg = Message.obtain();
         msg.obj=s;
         handler.sendMessage(msg);
        }
       }); 

      }
     });
     builder.setNegativeButton("取消", new DialogInterface.OnClickListener() {
      // 自动dismiss
      @Override
      public void onClick(DialogInterface dialogInterface, int i) {
      }
     });
     AlertDialog dialog = builder.create();
     dialog.show();
    }
    return true;
   }
  }); 

  webView.loadUrl("http://www.baidu.com");
 } 

 Handler handler =new Handler(){
  @Override
  public void handleMessage(Message msg) {
   super.handleMessage(msg);
   String picFile = (String) msg.obj;
   String[] split = picFile.split("/");
   String fileName = split[split.length-1];
   try {
    MediaStore.Images.Media.insertImage(getApplicationContext().getContentResolver(), picFile, fileName, null);
   } catch (FileNotFoundException e) {
    e.printStackTrace();
   }
   // 最后通知图库更新
   getApplicationContext().sendBroadcast(new Intent(Intent.ACTION_MEDIA_SCANNER_SCAN_FILE, Uri.parse("file://" + picFile)));
   Toast.makeText(context,"图片保存图库成功",Toast.LENGTH_LONG).show();
  }
 }; 

 // 监听返回键返回网页的上一层
 @Override
 public boolean onKeyDown(int keyCode, KeyEvent event) {
  if(keyCode == KeyEvent.KEYCODE_BACK && webView.canGoBack()){
   if(webView != null){
    webView.goBack();
    return true;
   }
  }
  return super.onKeyDown(keyCode, event);
 } 

} 

图片下载的工具类

import android.os.AsyncTask;
import android.os.Environment;
import android.util.Log; 

import java.io.File;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.net.URL;
import java.util.Random; 

/**
 * 图片下载的工具类
 */
public class DownPicUtil { 

 /**
  *下载图片，返回图片的地址
  * @param url
  */
 public static void downPic(String url,DownFinishListener downFinishListener){
  // 获取存储卡的目录
  String filePath = Environment.getExternalStorageDirectory().getPath();
  File file = new File(filePath+File.separator+"webViewCache");
  if(!file.exists()){
   file.mkdir();
  } 

  loadPic(file.getPath(),url,downFinishListener); 

 } 

 private static void loadPic(final String filePath, final String url, final DownFinishListener downFinishListener) {
  Log.e("下载图片的url",url);
  new AsyncTask<Void,Void,String>(){
   String fileName;
   InputStream is;
   OutputStream out; 

   @Override
   protected String doInBackground(Void... voids) { 

    // 下载文件的名称
    String[] split = url.split("/");
    String newString = split[split.length - 1];
    fileName =newString.substring(newString.length()-20,newString.length()-1) ;
    // 创建目标文件,不是文件夹
    File picFile = new File(filePath + File.separator + fileName);
    if(picFile.exists()){
     return picFile.getPath();
    } 

    try {
     URL picUrl = new URL(url);
     //通过图片的链接打开输入流
     is = picUrl.openStream();
     if(is==null){
      return null;
     }
     out = new FileOutputStream(picFile);
     byte[] b=new byte[1024];
     int end ;
     while ((end=is.read(b))!=-1){
      out.write(b,0,end);
     } 

     Log.e("OK??","----------");
     if(is!=null){
      is.close();
     } 

     if(out!=null){
      out.close();
     } 

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

    return picFile.getPath();
   } 

   @Override
   protected void onPostExecute(String s) {
    super.onPostExecute(s);
    if(s!=null){
     downFinishListener.getDownPath(s);
    }
   }
  }.execute();
 }
 //下载完成回调的接口
 public interface DownFinishListener{ 

  void getDownPath(String s);
 }
} 

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