Android使用webView长按保存下载网络图片

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);
}
}