Question

我尝试过尝试此代码“

private static String url_create_product = "http://10.0.2.2/android_connect/create_product.php";


class CreateNewProduct extends AsyncTask<String, String, String> {

    /**
     * Before starting background thread Show Progress Dialog
     * */
    @Override
    protected void onPreExecute() {
        super.onPreExecute();
        pDialog = new ProgressDialog(NewProductActivity.this);
        pDialog.setMessage("Creating Product..");
        pDialog.setIndeterminate(false);
        pDialog.setCancelable(true);
        pDialog.show();
    }

    /**
     * Creating product
     * */
    protected String doInBackground(String... args) {
        String name = inputName.getText().toString();
        String price = inputPrice.getText().toString();
        String description = inputDesc.getText().toString();

        // Building Parameters
        List<NameValuePair> params = new ArrayList<NameValuePair>();
        params.add(new BasicNameValuePair("name", name));
        params.add(new BasicNameValuePair("price", price));
        params.add(new BasicNameValuePair("description", description));

        // getting JSON Object
        // Note that create product url accepts POST method
        JSONObject json = jsonParser.makeHttpRequest(url_create_product,
                "POST", params);

        // check log cat fro response
        Log.d("Create Response", json.toString());

        // check for success tag
        try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // successfully created product
                Intent i = new Intent(getApplicationContext(), AllProductsActivity.class);
                startActivity(i);

                // closing this screen
                finish();
            } else {
                // failed to create product
            }
        } catch (JSONException e) {
            e.printStackTrace();
        }

        return null;
    }

    /**
     * After completing background task Dismiss the progress dialog
     * **/
    protected void onPostExecute(String file_url) {
        // dismiss the dialog once done
        pDialog.dismiss();
    }

}
}

我收到了错误

FATAL EXCEPTION: AsyncTask #2
Process: com.example.androidhive, PID: 2173
java.lang.RuntimeException: An error occured while executing doInBackground()
at android.os.AsyncTask$3.done(AsyncTask.java:300)
at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
at java.util.concurrent.FutureTask.run(FutureTask.java:242)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
at java.lang.Thread.run(Thread.java:841)
Caused by: java.lang.NullPointerException
at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:99)
at com.example.androidhive.NewProductActivity$CreateNewProduct.doInBackground(NewProductActivity.java:1)
at android.os.AsyncTask$2.call(AsyncTask.java:288)
at java.util.concurrent.FutureTask.run(FutureTask.java:237)  
... 3 more
android.view.WindowLeaked: Activity com.example.androidhive.NewProductActivity has leaked window com.android.internal.policy.impl.PhoneWindow$DecorView{b4d44420 V.E..... R.....ID 0,0-169,88} that was originally added here
at android.view.ViewRootImpl.<init>(ViewRootImpl.java:346)
at android.view.WindowManagerGlobal.addView(WindowManagerGlobal.java:248)
at android.view.WindowManagerImpl.addView(WindowManagerImpl.java:69)
at android.app.Dialog.show(Dialog.java:286)
at com.example.androidhive.NewProductActivity$CreateNewProduct.onPreExecute(NewProductActivity.java:76)
at android.os.AsyncTask.executeOnExecutor(AsyncTask.java:587)
at android.os.AsyncTask.execute(AsyncTask.java:535)
at com.example.androidhive.NewProductActivity$1.onClick(NewProductActivity.java:56)
at android.view.View.performClick(View.java:4424)
at android.view.View$PerformClick.run(View.java:18383)
at android.os.Handler.handleCallback(Handler.java:733)
at android.os.Handler.dispatchMessage(Handler.java:95)
at android.os.Looper.loop(Looper.java:137)
at android.app.ActivityThread.main(ActivityThread.java:4998)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:777)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:593)
at dalvik.system.NativeStart.main(Native Method)

我的php文件在C:/wamp/www/android_connect/create_product.php.htm如何通过网址？

Answer 1

开始onPostExecute方法的新活动

protected void onPostExecute(String file_url) {
        // dismiss the dialog once done
        pDialog.dismiss();

 try {
            int success = json.getInt(TAG_SUCCESS);

            if (success == 1) {
                // successfully created product
                Intent i = new Intent(getApplicationContext(), AllProductsActivity.class);
                startActivity(i);

                // closing this screen
                finish();
            } else {
                // failed to create product
            }
    }

onPostExecute方法在后台计算完成后调用。后台进程的结果在此方法中作为参数传递。现在您可以关闭进度对话框，以指示后台任务已完成。你无法在doInBackground方法中处理你的View。因为doInBackground方法是非UI线程。

Answer 2

protected void onPostExecute(String file_url) {
            // dismiss the dialog once product deleted
            pDialog.dismiss();
                if (file_url != null){
                Toast.makeText(Login.this, file_url, Toast.LENGTH_LONG).show();
            }

试试这个并说出回应是什么

Answer 3

我可能会迟到，但这可能为将来有需要的人节省一些时间..

问题是，如果您使用的是最新版本的WampServer（2.5），请将其卸载..而是为该特定示例安装WampServer 2.4版本。

它应该工作。这对我有用。希望这有助于某人！欢呼声..

P.S。即使我不知道为什么它不适用于以后的版本......希望有人能够启发我们......谢谢。

mysql和android之间的连接

3 个答案: