小编典典

无法解析符号“ OnClickListener”

java

我收到错误 消息“无法解析符号“ OnClickListener”“无法解析符号“ V””,
我开始使用Java,因此我不太擅长此语言,并且对语言不太熟悉

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);
    }
}

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2020-12-03

共1个答案

小编典典

我不确定您为什么要这样做,但请将初始化和侦听器移至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");
            }
        });
}

然后阅读编码的基础及其标准。

2020-12-03