Question

我有这个非常基本的应用程序，我试图随机显示骰子的图像。在这个阶段，我试图弄清楚为什么在新活动中不会一直显示骰子。当我从微调器开始第二个活动时出现问题，有时我可以多次启动第二个活动并且它工作正常，然后突然骰子消失了。这只发生在我尝试在主要活动中从微调器滚动骰子时，而不是在第二个活动中按下按钮时。

我希望有人可以帮助我！

主要活动

  package com.example.t.diceapplication;

  import android.content.Intent;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.View;
  import android.webkit.WebViewClient;
  import android.widget.AdapterView;
  import android.widget.ArrayAdapter;
  import android.widget.Spinner;
  import android.widget.Toast;

  public class MainActivity extends AppCompatActivity implements 
  AdapterView.OnItemSelectedListener {

Spinner spinner;

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

    spinner = findViewById(R.id.spinner);

    ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(this,
            R.array.NmbrOfDiceArray, android.R.layout.simple_spinner_item);

    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

    spinner.setAdapter(adapter);
    spinner.setOnItemSelectedListener(this);
}

@Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

    if (spinner.getSelectedItemPosition() == 1) {
        startActivity(new Intent(MainActivity.this, OneDiceActivity.class));
    }

}

@Override
public void onNothingSelected(AdapterView<?> parent) {

}

@Override
public void onResume() {
    super.onResume();
    spinner.setSelection(0);
}
}

第二项活动

  package com.example.t.diceapplication;

  import android.support.v4.content.ContextCompat;
  import android.support.v7.app.AppCompatActivity;
  import android.os.Bundle;
  import android.view.View;
  import android.widget.Button;
  import android.widget.ImageView;

  import java.util.Random;

  public class OneDiceActivity extends AppCompatActivity {

ImageView imageView;
Button button;


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

    imageView=findViewById(R.id.imageView2);
    button=findViewById(R.id.button);

    DisplayDice();
}

public void DisplayDice(){

    if (getRandomNumber()==1){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._diceone));
    }

    else if(getRandomNumber()==2){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._dicetwo));
    }

    else if (getRandomNumber()==3){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._dicethree));
    }

    else if (getRandomNumber()==4){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._dicefour));
    }

    else if (getRandomNumber()==5){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._dicefive));
    }

    else if (getRandomNumber()==6){
        imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._dicesix));
    }
}

public void rollDiceOnButtonClick(View view){
    DisplayDice();
}

public int getRandomNumber(){
    Random r = new Random();
    int Low = 1;
    int High = 6;
    return r.nextInt((High-Low)+1) + Low;
}

@Override
public void onBackPressed() {
    super.onBackPressed();
    this.finish();
}

}

Answer 1

我认为您的if逻辑存在问题。你得到的每个条件都有一个随机数，这可能导致你的if个分支都没有。试试这个。您只需要获取一次随机数。

    public void DisplayDice(){

        int diceRandom = getRandomNumber();

        // replace other instances to this method call with the variable
        if (diceRandom ==1){
 imageView.setImageDrawable(ContextCompat.getDrawable(this,R.drawable._diceone));
        }
    ....
    }

每次打开新活动时都不会显示Drawable

1 个答案: