Question

编译后我收到此错误：

error: incompatible types: <anonymous WebViewClient> cannot be converted to Context

错误来自这一行：

progress = ProgressDialog.show(this, "", "Loading...", true);

this应该是班级Context，我认为这与此有关，我不了解上下文是什么或如何解决它。< / p>

MainActivity.java

public class MainActivity extends AppCompatActivity
        implements NavigationView.OnNavigationItemSelectedListener {

    ProgressDialog progress;

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

        WebView webView = (WebView) findViewById(R.id.webView);
        webView.getSettings().setJavaScriptEnabled(true);

        webView.setWebViewClient(new WebViewClient() {
            DrawerLayout drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
            @Override
            public boolean shouldOverrideUrlLoading(WebView webView, String urlNewString) {
                webView.loadUrl("http://www.google.com");
                return true;
            }
            @Override
            public void onPageStarted(WebView webView, String url, Bitmap facIcon) {
                progress = ProgressDialog.show(this, "", "Loading...", true); // the offending line
            }
            @Override
            public void onPageFinished(WebView webView, String url) {
                drawer.closeDrawer(GravityCompat.START);
                progress.dismiss();
            }
            public void onReceivedError(WebView webView, int errorCode, String description, String failingUrl) {
                webView.loadUrl("file:///android_asset/www/error.html");
                drawer.openDrawer(GravityCompat.START);
                progress.dismiss();
            }
        });
        .
        .
    }
    .
    .
}

Answer 1

更改

progress = ProgressDialog.show(this, "", "Loading...", true);

到

progress = ProgressDialog.show(MainActivity.this, "", "Loading...", true);

该行代码位于匿名类的onPageStarted方法内。所以this指的是匿名类，而不是当前的活动上下文。

Android不兼容的类型错误

1 个答案: