java未知类“名称”

Question

我是Android Studio的新手，正在努力适应它。我曾尝试制作一个简单的应用程序，用户可以按下一个按钮，然后生成一个随机数。然而，当我在代码中使用变量时，它给了我“未知类'get'”和“未知类'random'”错误。代码如下：

package com.example.myapplication;

import 安卓.support.v7.app.AppCompatActivity;
import 安卓.os.Bundle;
import 安卓.widget.Button;
import 安卓.widget.SeekBar;
import 安卓.widget.TextView;

import java.util.Random;


public class MainActivity extends AppCompatActivity {

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

        final Button RollButton = findViewById(id.RollButton);
        final TextView resultsTextView = findViewById(id.ResultsTV);
        final SeekBar seekBar = findViewById(id.seekBar);

        RollButton.setOnClickListener(new onClickListener()
        {
            Random rnd = new Random(10);
            private int random = rnd.nextInt(seekBar.getProgress());
            CharSequence get = resultsTextView.getText();
            get = String.valueOf(random);
        });
    }
}

Answer 1

你的OnClickListener看起来不对，在这种情况下不能使用private。所以试试这个：

public class MainActivity extends AppCompatActivity {

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

    final Button RollButton = findViewById(id.RollButton);
    final TextView resultsTextView = findViewById(id.ResultsTV);
    final SeekBar seekBar = findViewById(id.seekBar);

    RollButton.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                Random rnd = new Random(10);
                int random = rnd.nextInt(seekBar.getProgress());
                CharSequence get = resultsTextView.getText();
                get = String.valueOf(random);
            }
        });
}
}