Android实现简易浏览器遇到问题的解决方法

public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.main); 
    init(); 
  } 
private void init() { 
   web_content = (WebView) findViewById(R.id.web_content); 
WebSettings set = web_content.getSettings(); 
    set.setSupportZoom(true); 
    set.setJavaScriptEnabled(true); 
    set.setCacheMode(WebSettings.LOAD_CACHE_ELSE_NETWORK); 
 
    View control = web_content.getZoomControls(); 
    FrameLayout layout = (FrameLayout) getWindow().getDecorView() 
        .findViewById(android.R.id.content); 
    FrameLayout.LayoutParams params = new FrameLayout.LayoutParams( 
        FrameLayout.LayoutParams.WRAP_CONTENT, 
        FrameLayout.LayoutParams.WRAP_CONTENT, Gravity.BOTTOM 
            | Gravity.RIGHT); 
    params.bottomMargin = 10; 
    params.rightMargin = 10; 
    layout.addView(control, params); 
 
    web_content.setOnTouchListener(new View.OnTouchListener() { 
 
      @Override 
      public boolean onTouch(View v, MotionEvent event) { 
        web_content.requestFocus(); 
        return false; 
      } 
    }); 
 
    web_content.setWebViewClient(new WebViewClient() { 
 
      @Override 
      public boolean shouldOverrideUrlLoading(WebView view, String url) { 
        view.loadUrl(url); 
        tx_address.setText(url); 
        return true; 
      } 
 
    }); 
web_content.loadUrl(parseUrl(defaultPage)); 
}