方案思路,
1.在点击图片的时候调用本地的java方法并给出响应的图片地址
2.本地获得图片地址后,开启一个遮罩activity进行显示和处理
第二步的实现很容易实现,关键是第一步的实现,在网页中点击图片不会调用本地的java代码。那么我们需要给这个点击事件加上相应的js函数,让点击事件调用的js函数来调用我们提前准备好的java函数,等我们捕获到图片的url剩下的就好处理了。
关键点就是给普通的html注入我们的js函数,让图片能够响应点击并调用js函数,在通过js函数来调用我们的java函数。听起来好像有点绕,不过也不难,下面我们用代码实现下
对java和js交互还不熟悉的同学,请参照前面的文章
http://blog.csdn.net/wangtingshuai/article/details/8631835
这次实例的主要功能:点击图片在新的activity中展示,对图片能够进行手势操作,包括双指缩放等
效果图
加载webview的activity代码
- package wst.webview;
- import android.annotation.SuppressLint;
- import android.app.Activity;
- import android.content.Context;
- import android.content.Intent;
- import android.graphics.Bitmap;
- import android.os.Bundle;
- import android.webkit.WebView;
- import android.webkit.WebViewClient;
- @SuppressLint(“SetJavaScriptEnabled”)
- public class MainActivity extends Activity {
- private WebView contentWebView = null;
- @SuppressLint(“SetJavaScriptEnabled”)
- @Override
- public void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.main);
- contentWebView = (WebView) findViewById(R.id.webview);
- // 启用javascript
- contentWebView.getSettings().setJavaScriptEnabled(true);
- // 随便找了个带图片的网站
- contentWebView.loadUrl(“http://www.weim.me/12408.html”);
- // 添加js交互接口类,并起别名 imagelistner
- contentWebView.addJavascriptInterface(new JavascriptInterface(this), “imagelistner”);
- contentWebView.setWebViewClient(new MyWebViewClient());
- }
- // 注入js函数监听
- private void addImageClickListner() {
- // 这段js函数的功能就是,遍历所有的img几点,并添加onclick函数,函数的功能是在图片点击的时候调用本地java接口并传递url过去
- contentWebView.loadUrl(“javascript:(function(){“ +
- “var objs = document.getElementsByTagName(/”img/”); “ +
- “for(var i=0;i<objs.length;i++) “ +
- “{“
- + ” objs[i].onclick=function() “ +
- ” { “
- + ” window.imagelistner.openImage(this.src); “ +
- ” } “ +
- “}” +
- “})()”);
- }
- // js通信接口
- public class JavascriptInterface {
- private Context context;
- public JavascriptInterface(Context context) {
- this.context = context;
- }
- public void openImage(String img) {
- System.out.println(img);
- //
- Intent intent = new Intent();
- intent.putExtra(“image”, img);
- intent.setClass(context, ShowWebImageActivity.class);
- context.startActivity(intent);
- System.out.println(img);
- }
- }
- // 监听
- private class MyWebViewClient extends WebViewClient {
- @Override
- public boolean shouldOverrideUrlLoading(WebView view, String url) {
- return super.shouldOverrideUrlLoading(view, url);
- }
- @Override
- public void onPageFinished(WebView view, String url) {
- view.getSettings().setJavaScriptEnabled(true);
- super.onPageFinished(view, url);
- // html加载完成之后,添加监听图片的点击js函数
- addImageClickListner();
- }
- @Override
- public void onPageStarted(WebView view, String url, Bitmap favicon) {
- view.getSettings().setJavaScriptEnabled(true);
- super.onPageStarted(view, url, favicon);
- }
- @Override
- public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
- super.onReceivedError(view, errorCode, description, failingUrl);
- }
- }
- }
展示图片的activity代码
- package wst.webview;
- import java.io.IOException;
- import java.io.InputStream;
- import java.net.URL;
- import android.app.Activity;
- import android.graphics.drawable.BitmapDrawable;
- import android.graphics.drawable.Drawable;
- import android.os.Bundle;
- import android.widget.TextView;
- public class ShowWebImageActivity extends Activity {
- private TextView imageTextView = null;
- private String imagePath = null;
- private ZoomableImageView imageView = null;
- @Override
- protected void onCreate(Bundle savedInstanceState) {
- super.onCreate(savedInstanceState);
- setContentView(R.layout.show_webimage);
- this.imagePath = getIntent().getStringExtra(“image”);
- this.imageTextView = (TextView) findViewById(R.id.show_webimage_imagepath_textview);
- imageTextView.setText(this.imagePath);
- imageView = (ZoomableImageView) findViewById(R.id.show_webimage_imageview);
- try {
- imageView.setImageBitmap(((BitmapDrawable) ShowWebImageActivity.loadImageFromUrl(this.imagePath)).getBitmap());
- } catch (IOException e) {
- e.printStackTrace();
- }
- }
- public static Drawable loadImageFromUrl(String url) throws IOException {
- URL m = new URL(url);
- InputStream i = (InputStream) m.getContent();
- Drawable d = Drawable.createFromStream(i, “src”);
- return d;
- }
- }
图片布局文件
- <?xml version=“1.0” encoding=“utf-8”?>
- <LinearLayout xmlns:android=“http://schemas.android.com/apk/res/android”
- android:layout_width=“fill_parent”
- android:layout_height=“fill_parent”
- android:orientation=“vertical” >
- <!– TODO 默认占位图 –>
- <wst.webview.ZoomableImageView
- android:id=“@+id/show_webimage_imageview”
- android:layout_width=“fill_parent”
- android:layout_height=“fill_parent”
- android:scaleType=“matrix”
- android:src=“@drawable/icon” />
- <TextView
- android:id=“@+id/show_webimage_imagepath_textview”
- android:layout_width=“fill_parent”
- android:layout_height=“wrap_content”
- android:gravity=“center”
- android:textColor=“#ffff0000” />
- </LinearLayout>
希望对大家有所帮助
源代码附上
http://download.csdn.net/detail/wangtingshuai/5109179
原创文章,作者:奋斗,如若转载,请注明出处:https://blog.ytso.com/tech/app/5599.html