Android开发实现webview中img标签加载本地图片的方法

WebSettings webSettings=webView.getSettings();
//允许webview对文件的操作
webSettings.setAllowUniversalAccessFromFileURLs(true);
webSettings.setAllowFileAccess(true);
webSettings.setAllowFileAccessFromFileURLs(true);

String path= "file://"+Environment.getExternalStorageDirectory()+ File.separator+"123.jpg";

package com.example.a5.myapplication;
import android.os.Environment;
import android.support.v7.app.AlertDialog;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebChromeClient;
import android.webkit.WebSettings;
import android.webkit.WebView;
import java.io.File;
public class MainActivity extends AppCompatActivity {
  private WebView webView;
  @Override
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    webView= (WebView) findViewById(R.id.webView);
    WebSettings webSettings=webView.getSettings();
    //允许webview对文件的操作
    webSettings.setAllowUniversalAccessFromFileURLs(true);
    webSettings.setAllowFileAccess(true);
    webSettings.setAllowFileAccessFromFileURLs(true);
    //用于js调用Android
    webSettings.setJavaScriptEnabled(true);
    //设置编码方式
    webSettings.setDefaultTextEncodingName("utf-8");
    webView.setWebChromeClient(new chromClient());
    //访问Android assets文件夹内的
    String url="file:///android_asset/test.html";
    //访问网页Html
//    String url="http://192.168.1.121:8080/jsandroid/index.html"；
    runWebView(url);
  }
  private class chromClient extends WebChromeClient{
    @Override
    public void onProgressChanged(WebView view, int newProgress) {
      if(newProgress==100){
        //页面加载完成执行的操作
        String path= "file://"+Environment.getExternalStorageDirectory()+ File.separator+"123.jpg";
        String action="javascript:aa('"+path+"')";
        new AlertDialog.Builder(MainActivity.this)
            .setMessage(action)
            .show();
        runWebView(action);
      }
      super.onProgressChanged(view, newProgress);
    }
  }
  private void runWebView(final String url){
    runOnUiThread(new Runnable() {
      @Override
      public void run() {
        webView.loadUrl(url);
      }
    });
  }
}