Question

我有一个活动，其中有一个webview。当webview转到几页并且我点击设备上的后退按钮运行正常，但如果我单击操作栏中的后退按钮然后返回错误。我可以在操作栏中设置功能返回按钮，如设备中的后退按钮吗？

这是我的代码：

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.tes_backbutton);

    getSupportActionBar().setDisplayHomeAsUpEnabled(true);
    getSupportActionBar().setDisplayShowHomeEnabled(true);

    view = (WebView)findViewById(R.id.wv_tes);
    progressBar = (ProgressBar)findViewById(R.id.prgbarhome);

    view.setWebViewClient(new WebViewClient());
    view.loadUrl(URL);
    view.setWebChromeClient(new WebChromeClient() {
        @Override
        public boolean onJsAlert(WebView view, String url, String message, JsResult result) {
            //Required functionality here
            return super.onJsAlert(view, url, message, result);
        }
    });


    view.setWebViewClient(new WebViewClient() {
        ProgressDialog progressDialog;

        //Show loader on url load
        @Override
        public void onPageStarted(WebView view, String url, Bitmap favicon) {
            if (progressDialog == null) {
                // in standard case YourActivity.this
                progressDialog = new ProgressDialog(tes_backbutton.this);
                progressDialog.setMessage("Loading...");
                progressDialog.show();
            }
        }

        public void onPageFinished(WebView view, String url) {
            try {
                progressDialog.dismiss();
                progressDialog = null;
            } catch (Exception exception) {
                exception.printStackTrace();
            }
        }

        public void onReceivedError(WebView view, int errorCode, String description, String failingUrl) {
            Intent myIntent = new Intent(tes_backbutton.this, main_noconnect.class);
            tes_backbutton.this.startActivity(myIntent);
        }
    });

    view.canGoBack();
    view.setOnKeyListener(new View.OnKeyListener() {

        public boolean onKey(View v, int keyCode, KeyEvent event) {
            if (keyCode == KeyEvent.KEYCODE_BACK
                    && event.getAction() == MotionEvent.ACTION_UP
                    && view.canGoBack()) {
                view.goBack();
                return true;
            }
            return false;
        }
    });
}

@Override
public boolean onSupportNavigateUp() {
    onBackPressed();
    return true;
}

Answer 1

如果您想在操作栏中点击后退箭头后执行任何操作，则需要覆盖onOptionsItemSelected方法

@Override
public boolean onOptionsItemSelected(MenuItem menuItem) {

    switch (menuItem.getItemId()) {
        case android.R.id.home:
            onBackPressed(); //finishes the activity
            return true;
    }
    return super.onOptionsItemSelected(menuItem);
}

Answer 2

操作栏中的“后退”按钮应与设备的后退按钮不同。你不希望他们两个都做同样的事情。操作栏中的按钮应该用作“向上”按钮而不是“后退”按钮。请详细了解Providing Up Navigation。

我希望这会对你有所帮助。

Answer 3

你可以使用onBackPressed（）;方法

Answer 4

@覆盖 public boolean onOptionsItemSelected（MenuItem menuItem）{

switch (menuItem.getItemId()) {
    case android.R.id.home:
      if(mWebView.canGoBack() == true){
        mWebView.goBack();
      }else{
        onBackPressed(); //finishes the activity
      }
    return true;
}
return super.onOptionsItemSelected(menuItem);

}

Answer 5

you can use webview.cangoback() method for navigating between different web pages in webview 

@Override
public boolean onOptionsItemSelected(MenuItem menuItem) {

    switch (menuItem.getItemId()) {
        case android.R.id.home:
           if(view.cangoback()){
view.goback();
}
else{
finish();
}
break;






    }
    return super.onOptionsItemSelected(menuItem);
}

如何在动作栏中创建功能后退按钮，如设备android中的后退按钮

5 个答案: