方法 onCreate(Bundle) 已經在類 MainActivity 中定義

Question

我想在我的應用程序中有兩個 seekBars。 為此，我有兩個創建命令，但我的錯誤是方法 onCreate(Bundle) 已在類 MainActivity 中定義。 所以我試圖刪除其中一個，但隨后很多命令變成紅色並說無法解析符號。 如何將兩個 seekBars 與一個 on create 功能一起使用？ 也許我應該提到，在我復制粘貼之前，第一個seekBar就像一個魅力......

我對編程應用程序很陌生。

提前致謝。

package com.car.bluetooth.bluetoothcar;

import android.os.Bundle;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.SeekBar;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

int gas = 0;
int steering = 0;

//Variable Anpassen GAS

private SeekBar seekBarGas;
private TextView textViewGas;

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

seekBarGas = (SeekBar) findViewById(R.id.seekBarGas);
textViewGas = (TextView) findViewById(R.id.textViewGas);
seekBarGas.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        textViewGas.setText(progress + "  /  " + seekBarGas.getMax());
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

        }
   });
}





//Variable Anpassen Steering

private SeekBar seekBarSteering;
private TextView textViewSteering;

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

    seekBarSteering = (SeekBar) findViewById(R.id.seekBarSteering);
    textViewSteering = (TextView) findViewById(R.id.textViewSteering);
    seekBarSteering.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            textViewSteering.setText(progress + "  /  " + seekBarSteering.getMax());
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    });
}



}

Answer 1

您的代碼中的問題是您有兩次onCreate方法。 因此，為了完成這項工作，您必須刪除其中之一。

您的代碼應如下所示：

import android.os.Bundle;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.android.material.snackbar.Snackbar;

import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;

import android.util.Log;
import android.view.View;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.SeekBar;
import android.widget.TextView;


public class MainActivity extends AppCompatActivity {

int gas = 0;
int steering = 0;

//Variable Anpassen GAS

private SeekBar seekBarGas;
private TextView textViewGas;

private SeekBar seekBarSteering;
private TextView textViewSteering;

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

seekBarGas = (SeekBar) findViewById(R.id.seekBarGas);
textViewGas = (TextView) findViewById(R.id.textViewGas);
seekBarGas.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        textViewGas.setText(progress + "  /  " + seekBarGas.getMax());
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

        }
   });

   seekBarSteering = (SeekBar) findViewById(R.id.seekBarSteering);
    textViewSteering = (TextView) findViewById(R.id.textViewSteering);
    seekBarSteering.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
        @Override
        public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
            textViewSteering.setText(progress + "  /  " + seekBarSteering.getMax());
        }

        @Override
        public void onStartTrackingTouch(SeekBar seekBar) {

        }

        @Override
        public void onStopTrackingTouch(SeekBar seekBar) {

        }
    });
}

}

Answer 2

您有一個 onCreate 方法的重復聲明，因此請刪除您的活動中的第二個 on Create 方法

代碼看起來像這樣

public class MainActivity extends AppCompatActivity {

int gas = 0;
int steering = 0;

//Variable Anpassen GAS

  private SeekBar seekBarGas;
  private TextView textViewGas;

   private SeekBar seekBarSteering;
   private TextView textViewSteering;

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

seekBarGas = (SeekBar) findViewById(R.id.seekBarGas);
textViewGas = (TextView) findViewById(R.id.textViewGas);
seekBarGas.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
@Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
    textViewGas.setText(progress + "  /  " + seekBarGas.getMax());
}

@Override
public void onStartTrackingTouch(SeekBar seekBar) {

}

@Override
public void onStopTrackingTouch(SeekBar seekBar) {

    }
  });

seekBarSteering = (SeekBar) findViewById(R.id.seekBarSteering);
textViewSteering = (TextView) findViewById(R.id.textViewSteering);
seekBarSteering.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
    @Override
    public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
        textViewSteering.setText(progress + "  /  " + seekBarSteering.getMax());
    }

    @Override
    public void onStartTrackingTouch(SeekBar seekBar) {

    }

    @Override
    public void onStopTrackingTouch(SeekBar seekBar) {

    }
});
}

}

Android 活動生命周期方法在您的活動中調用一次而不是兩次

https://developer.android.com/guide/components/activities/activity-lifecycle

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