无法解析符号“OnClickListener”

我收到错误无法解析符号“OnClickListener”和“无法解析符号”V“”我开始进入Java所以我不是很擅长这个并且不太熟悉这种语言

我的代码：

package com.emiliogaines.counter.counter; import android.app.Activity; import android.os.Bundle; import android.view.Menu; import android.view.MenuItem; import android.view.View; import android.widget.Button; import android.widget.TextView; public class MainActivity extends Activity { Button mButton = (Button) findViewById(R.id.More); mButton.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View v) { final TextView mTextView = (TextView) findViewById(R.id.Antal); mTextView.setText("Some Text"); } }); @Override public boolean onCreateOptionsMenu(Menu menu) { // Inflate the menu; this adds items to the action bar // if it is present. getMenuInflater().inflate(R.menu.menu_main, menu); return true; } @Override public boolean onOptionsItemSelected(MenuItem item) { // Handle action bar item clicks here. The action bar will // automatically handle clicks on the Home/Up button, so long // as you specify a parent activity in AndroidManifest.xml. int id = item.getItemId(); //noinspection SimplifiableIfStatement if (id == R.id.action_settings) { return true; } return super.onOptionsItemSelected(item); } } 

Answer 1

我不确定你为什么这样做，但请将初始化和监听器移动到onCreate() ：

只需剪切以下代码行：

  Button mButton = (Button) findViewById(R.id.More); mButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { final TextView mTextView = (TextView) findViewById(R.id.Antal); mTextView.setText("Some Text"); } }); 

并将它们粘贴到onCreate() ：

 @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.main); Button mButton = (Button) findViewById(R.id.More); final TextView mTextView = (TextView)findViewById(R.id.Antal); mButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { mTextView.setText("Some Text"); } }); } 

然后去阅读编码的基础和它的标准。

Answer 2

U必须将其存储到onCreate方法中：

 @Override protected void onCreate(Bundle savedInstanceState) { Button mButton = (Button) findViewById(R.id.More); mButton.setOnClickListener(new View.OnClickListener() { public void onClick(View v) { final TextView mTextView = (TextView)findViewById(R.id.Antal); mTextView.setText("Some Text"); } }); }