引起：java.lang.ClassCastException：android.widget.TextView无法强制转换为android.widget.EditText

Question

我尝试了清理项目甚至重建项目，没有变化....应用程序已停止，日志错误为：

package com.example.dota.jsonphp;

import android.app.Activity;
import android.os.AsyncTask;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.EditText;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.net.HttpURLConnection;
import java.net.MalformedURLException;
import java.net.URL;

public class MainActivity extends Activity implements View.OnClickListener
{
   private EditText textview1;
   private Button btnhit;

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

        textview1 = (EditText) findViewById(R.id.textview);
        btnhit = (Button) findViewById(R.id.btnhit);
        btnhit.setOnClickListener(this);
    }

    @Override
    public void onClick(View v) {
        new jsontask().execute("http://localhost/phppage.php");
    }


    public class jsontask extends AsyncTask<String, String, String> {


        @Override
        protected String doInBackground(String... params) {
            HttpURLConnection connection = null;
            BufferedReader reader = null;
            try {
                URL url = new URL(params[0]);
                connection = (HttpURLConnection) url.openConnection();
                connection.connect();

                InputStream stream = connection.getInputStream();
                reader = new BufferedReader(new InputStreamReader(stream));

                StringBuffer buffer = new StringBuffer();
                String line = "";
                while ((line = reader.readLine()) != null) {
                    buffer.append(line);

                }
                return buffer.toString();


            } catch (MalformedURLException e) {
                e.printStackTrace();
            } catch (IOException e) {
                e.printStackTrace();
            } finally {
                if (connection != null) {
                    connection.disconnect();
                }
                try {
                    if (reader != null) {
                        reader.close();
                    }
                } catch (IOException e) {
                    e.printStackTrace();
                }

            }
            return null;
        }

        @Override
        protected void onPostExecute(String result) {
            super.onPostExecute(result);
            textview1.setText(result);
        }

    }


}

布局：

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent"
    android:layout_height="match_parent" android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    android:paddingBottom="@dimen/activity_vertical_margin"
    app:layout_behavior="@string/appbar_scrolling_view_behavior"
    tools:showIn="@layout/activity_main" tools:context=".MainActivity"
    android:orientation="vertical"
    android:weightSum="1">

        <TextView
            android:id="@+id/textview"
            android:layout_width="265dp"
            android:layout_height="wrap_content"
            android:text="helloworld"
            />
        <Button
            android:layout_width="100dp"
            android:layout_height="wrap_content"
            android:id="@+id/btnhit"
            android:text="HIt"
            android:layout_weight="0.06" />

</LinearLayout>

Answer 1

private TextView textview1;
textview1 = (TextView) findViewById(R.id.textview);