0

Android デバイスの戻るボタンを、WebView で後方に移動する方法にしようとしています。ただし、戻るボタンをクリックすると、代わりに強制終了します。

これは私の.javaファイルです（パッケージ名を編集しました）：

package ----;

import android.app.Activity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;

public class ---- extends Activity {
WebView mainWebView;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    WebView mainWebView = (WebView) findViewById(R.id.mainWebView);

    WebSettings webSettings = mainWebView.getSettings();
    webSettings.setJavaScriptEnabled(true);

    mainWebView.setWebViewClient(new MyCustomWebViewClient());
    mainWebView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

    mainWebView.loadUrl("https://app.tent.is/global");
}

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    // Check if the key event was the Back button and if there's history
    if ((keyCode == KeyEvent.KEYCODE_BACK) && mainWebView.canGoBack()) {
        mainWebView.goBack();
        return true;
    }
    // If it wasn't the Back key or there's no web page history, bubble up to the default
    // system behavior (probably exit the activity)
    return super.onKeyDown(keyCode, event);
}

private class MyCustomWebViewClient extends WebViewClient {
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url) {
        view.loadUrl(url);
        return true;
    }
  }
}
4

2 に答える 2

11

ここ

WebView mainWebView = (WebView) findViewById(R.id.mainWebView);

で変わる

mainWebView = (WebView) findViewById(R.id.mainWebView);

WebView mainWebView;事は、前に宣言したオブジェクトonCreateであり、初期化されることはありません。

于 2012-10-15T06:03:53.303 に答える
0

コードを使用できます

  package ----;

    import android.app.Activity;
    import android.os.Bundle;
    import android.view.KeyEvent;
    import android.view.View;
    import android.webkit.WebSettings;
    import android.webkit.WebView;
    import android.webkit.WebViewClient;

    public class ---- extends Activity {
    WebView mainWebView;
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        mainWebView = (WebView) findViewById(R.id.mainWebView);

        WebSettings webSettings = mainWebView.getSettings();
        webSettings.setJavaScriptEnabled(true);

        mainWebView.setWebViewClient(new MyCustomWebViewClient());
        mainWebView.setScrollBarStyle(View.SCROLLBARS_INSIDE_OVERLAY);

        mainWebView.loadUrl("https://app.tent.is/global");
    }

    @Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        // Check if the key event was the Back button and if there's history
        if ((keyCode == KeyEvent.KEYCODE_BACK) && mainWebView.canGoBack()) {
            mainWebView.goBack();
            return true;
        }
        // If it wasn't the Back key or there's no web page history, bubble up to the default
        // system behavior (probably exit the activity)
        return super.onKeyDown(keyCode, event);
    }

    private class MyCustomWebViewClient extends WebViewClient {
        @Override
        public boolean shouldOverrideUrlLoading(WebView view, String url) {
            view.loadUrl(url);
            return true;
        }
      }
    }
于 2012-10-15T07:07:59.387 に答える