Question

我正在努力从我正在做的示例应用程序中获取最终结果。我通过在stackoverflow上获得人们的帮助解决了我的许多问题，但我仍然无法解决这个问题！有人可以编辑这段代码，所以我第二次使用它时没有收到错误“MainActivity类型已定义”吗？我可以看到为什么这是错误的格式，但我不知道如何解决它！这是代码：

package com.example.progressdialog;

import android.app.Activity;
import android.app.ProgressDialog;
import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;


public class MainActivity extends Activity {


   public class mainactivity2 {

    }
private ProgressDialog progress;
   @Override
   protected void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.main);
      progress = new ProgressDialog(this);
   }


   public void open(View view){
      progress.setMessage("Progressing!");
      progress.setProgressStyle(ProgressDialog.STYLE_HORIZONTAL);
      progress.setIndeterminate(false);
      progress.show();

   final int totalProgressTime = 100;

   final Thread t = new Thread(){

   @Override
   public void run(){

      int jumpTime = 0;
      while(jumpTime < totalProgressTime){
         try {
            sleep(500);
            jumpTime += 1;
            progress.setProgress(jumpTime);
         } catch (InterruptedException e) {


           e.printStackTrace();
         }

      }

   }
   };
   t.start();

   }
   @Override
   public boolean onCreateOptionsMenu(Menu menu) {

      getMenuInflater().inflate(R.menu.main, menu);
      return true;
   }
}

public class MainActivity extends Activity {
    /** Called when the activity is first created. */
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main2);

        Button next = (Button) findViewById(R.id.button2);
        next.setOnClickListener(new View.OnClickListener() {
            public void onClick(View view) {
                Intent myIntent = new Intent(view.getContext(), Activity2.class);
                startActivityForResult(myIntent, 0);
            }

        });
    }
}

Answer 1

您要定义MainActivity两次。而且由于某种原因，你的第一个MainActivity中有一个内部mainactivity2类。

Answer 2

public class MainActivity extends Activity {
    /** Called when the activity is first created. */


public class MainActivity extends Activity {

???您正尝试两次定义MainActivity。你看到了吗？

错误：已定义类型MainActivity

2 个答案: