我有以下JAVA Android Webview代码。后面button在Android Studio模拟器中正常工作，但是当我在任何Android设备上安装相同的apk时，它不再起作用。单击后面button只会使移动设备上的应用程序崩溃。有人可以帮忙吗？
import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Intent;
import android.graphics.Bitmap;
import android.net.Uri;
import android.os.Build;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.KeyEvent;
import android.view.View;
import android.webkit.ValueCallback;
import android.webkit.WebSettings;
import android.webkit.WebView;
import android.webkit.WebViewClient;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity{
public static final String PAGE_URL = "www.domain.com";
WebView webb;
private static final int INPUT_FILE_REQUEST_CODE = 1;
private static final int FILECHOOSER_RESULTCODE = 1;
private static final String TAG = MainActivity.class.getSimpleName();
private WebSettings webSettings;
private ValueCallback<Uri> mUploadMessage;
private Uri mCapturedImageURI = null;
private ValueCallback<Uri[]> mFilePathCallback;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
webb = (WebView) findViewById(R.id.webb1);
webSettings = webb.getSettings();
webSettings.setJavaScriptEnabled(true);
webSettings.setLoadWithOverviewMode(true);
webSettings.setAllowFileAccess(true);
//webb.setWebViewClient(new WebViewClient());
webb.setWebViewClient(new Client());
if (Build.VERSION.SDK_INT >= 19) {
webb.setLayerType(View.LAYER_TYPE_HARDWARE, null);
} else if (Build.VERSION.SDK_INT >= 11 && Build.VERSION.SDK_INT < 19) {
webb.setLayerType(View.LAYER_TYPE_SOFTWARE, null);
}
webb.loadUrl(PAGE_URL);
}
@Override
public void onActivityResult(int requestCode, int resultCode, Intent data) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
if (requestCode != INPUT_FILE_REQUEST_CODE || mFilePathCallback == null) {
super.onActivityResult(requestCode, resultCode, data);
return;
}
Uri[] results = null;
if (resultCode == Activity.RESULT_OK) {
if (data == null) {
if (mCameraPhotoPath != null) {
results = new Uri[]{Uri.parse(mCameraPhotoPath)};
}
} else {
String dataString = data.getDataString();
if (dataString != null) {
results = new Uri[]{Uri.parse(dataString)};
}
}
}
mFilePathCallback.onReceiveValue(results);
mFilePathCallback = null;
} else if (Build.VERSION.SDK_INT <= Build.VERSION_CODES.KITKAT) {
if (requestCode != FILECHOOSER_RESULTCODE || mUploadMessage == null) {
super.onActivityResult(requestCode, resultCode, data);
return;
}
if (requestCode == FILECHOOSER_RESULTCODE) {
if (null == this.mUploadMessage) {
return;
}
Uri result = null;
try {
if (resultCode != RESULT_OK) {
result = null;
} else {
result = data == null ? mCapturedImageURI : data.getData();
}
} catch (Exception e) {
Toast.makeText(getApplicationContext(), "activity :" + e,
Toast.LENGTH_LONG).show();
}
mUploadMessage.onReceiveValue(result);
mUploadMessage = null;
}
}
return;
}
@Override
public void onBackPressed() {
webb = (WebView) findViewById(R.id.webb1);
if (webb.canGoBack()) {
webb.goBack();
} else {
super.onBackPressed();
}
}
public boolean onKeyDown(int keyCode, KeyEvent event) {
if ((keyCode == KeyEvent.KEYCODE_BACK) && webb != null && webb.canGoBack()) {
webb.goBack();
return false;
}
return super.onKeyDown(keyCode, event);
}
public class Client extends WebViewClient {
ProgressDialog progressDialog;
public boolean shouldOverrideUrlLoading(WebView view, String url) {
if (url.contains("mailto:")) {
view.getContext().startActivity(
new Intent(Intent.ACTION_VIEW, Uri.parse(url)));
return true;
} else if (url.contains("tel:")) {
Intent intent = new Intent(Intent.ACTION_DIAL, Uri.parse(url));
startActivity(intent);
view.reload();
return true;
} else {
view.loadUrl(url);
return true;
}
}
public void onPageFinished(WebView view, String url) {
try {
if (progressDialog.isShowing()) {
progressDialog.dismiss();
progressDialog = null;
}
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
}
由于
答案 0 :(得分：1)
请在onBackPressed活动
if (webb.canGoBack()) {
webb.goBack();
} else {
finish();
}
答案 1 :(得分：0)
以下是android studio中的日志：
W/zygote: Attempt to remove non-JNI local reference, dumping thread
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
I/zygote: NativeAlloc concurrent copying GC freed 0(44KB) AllocSpace objects, 0(0B) LOS objects, 49% free, 2MB/4MB, paused 27us total 109.624ms
W/zygote: Attempt to remove non-JNI local reference, dumping thread
W/zygote: Attempt to remove non-JNI local reference, dumping thread
W/zygote: Attempt to remove non-JNI local reference, dumping thread
I/zygote: NativeAlloc concurrent copying GC freed 784(86KB) AllocSpace objects, 0(0B) LOS objects, 50% free, 1973KB/3MB, paused 21us total 113.240ms
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
W/zygote: Attempt to remove non-JNI local reference, dumping thread
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
I/zygote: NativeAlloc concurrent copying GC freed 3435(216KB) AllocSpace objects, 0(0B) LOS objects, 49% free, 1789KB/3MB, paused 52us total 118.789ms
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
I/zygote: Do full code cache collection, code=199KB, data=149KB
I/zygote: After code cache collection, code=197KB, data=114KB
W/zygote: Attempt to remove non-JNI local reference, dumping thread
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)
I/zygote: NativeAlloc concurrent copying GC freed 1118(111KB) AllocSpace objects, 0(0B) LOS objects, 49% free, 1844KB/3MB, paused 45us total 142.205ms
D/EGL_emulation: eglMakeCurrent: 0xa297f160: ver 2 0 (tinfo 0x91cba300)