Question

ㅡㅡㅡㅡㅡㅡㅡㅡㅡ我解决了ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ

  // Marshmallow below
@Override
public boolean shouldOverrideUrlLoading(WebView view, String url) {
    if (view.canGoBack()) {
       view.loadUrl(url);
       return true;
    }
    return false;
}


// Nougat above
@TargetApi(Build.VERSION_CODES.N)
@Override
public boolean shouldOverrideUrlLoading(WebView view, WebResourceRequest request) {

    if (request.isRedirect()){
        view.loadUrl(url);
        return true;
    }
    return false;
}

ㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡㅡ

后退按钮不起作用，它工作得很好，我没有更新代码。

如果我按下后退按钮，它应该在页面回家时关闭。但是，当我按下后退按钮时，我的代码应用程序将被关闭。

我认为Back代码（goBack，canGoBack）无法正常工作。

错误代码

E/ViewSystem: ViewRootImpl #2 Surface is not valid.
E/File: fail readDirectory() errno=2
W/DisplayListCanvas: DisplayListCanvas is started on unbinded RenderNode (without mOwningView)
enter code here

MainActivity.java

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.webkit.WebView;
import android.webkit.WebViewClient;

公共类MainActivity扩展了AppCompatActivity {

private WebView myWebView;
public static final String INTENT_PROTOCOL_START = "intent:";
public static final String INTENT_PROTOCOL_INTENT = "#Intent;";
public static final String INTENT_PROTOCOL_END = ";end;";
public static final String GOOGLE_PLAY_STORE_PREFIX = "market://details?id=";

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    myWebView = (WebView)findViewById(R.id.webview);


    myWebView.setWebViewClient(new MyWebViewClient());
    myWebView.goBack();
    myWebView.getSettings().setJavaScriptCanOpenWindowsAutomatically(true);
    myWebView.getSettings().setJavaScriptEnabled(true);

    myWebView.loadUrl("http://fpfriends.com");
}

private class MyWebViewClient extends WebViewClient{
    @Override
    public boolean shouldOverrideUrlLoading(WebView view, String url){
        view.loadUrl(url);
        return true;
    }
}
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if ((keyCode == KeyEvent.KEYCODE_BACK) && myWebView.canGoBack()) {
        myWebView.goBack();
        return true;
    }

    return super.onKeyDown(keyCode, event);
}

// I tried below code too.
@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (event.getAction() == KeyEvent.ACTION_DOWN) {
        switch (keyCode) {
            case KeyEvent.KEYCODE_BACK:
                if (myWebView.canGoBack()) {
                    myWebView.goBack();
                } else {
                    finish();
                }
               return true;
        }
    }
    return super.onKeyDown(keyCode, event); //
 }
}

Answer 1

尝试调用onBackPressed

@Override
public void onBackPressed() {
    super.onBackPressed();
}

或像这样更改你的onKeyDown方法

@Override
public boolean onKeyDown(int keyCode, KeyEvent event) {
    if (keyCode == KeyEvent.KEYCODE_BACK && event.getRepeatCount() == 0) {

        finish();
        return true;
    }
    return super.onKeyDown(keyCode, event);
}

Answer 2

你应该这样做，见下文

@Override
    public boolean onKeyDown(int keyCode, KeyEvent event) {
        if ((keyCode == KeyEvent.KEYCODE_BACK)) {
            if (myWebView.canGoBack())//test if your webview can go back more if not it will go to else 
                myWebView.goBack();
            else
                finish();
            return true;
        }
        return super.onKeyDown(keyCode, event);
    }

Webview后退按钮（goback）不起作用

2 个答案: