Question

我有一个可点击的TextView，当你按下它时，它从一个数组列表中检索元素并在同一个TextView上随机显示它们。每次按下TextView，它都会显示另一个元素。

现在，我想用显示的顺序保存这些元素，然后按下前一个按钮，每次显示已被显示的元素的前一个元素，直到第一个元素。< / p>

我自己尝试，但它只保留一个元素而不是所有显示的元素，并且不会向后显示它们。

ArrayList<String> random = new ArrayList<String>();

Text_View.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    if (myString==null||myString.size()==0){
                        myString = new ArrayList<String>();
                        Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                        Collections.shuffle(myString);
                    }
                    String q = myString.remove(0);
                    Text_View.setText(q);


                    for (int i=0;i<myString.size();i++) {
                        random.add(q);
                    }
                }

            });

            prev.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    for (int counter = myString.size() - 1; counter >= 0; counter--) {
                        Text_View.setText(random.get(counter));
                    }
                }
            });

谢谢..

的更新

我发布了你指出的修正代码，但仍然不起作用，但更糟糕的是，它崩溃了！

公共类MyActivity扩展了Activity {

public int counter;

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

       Text_View.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {

                   int counter = myString.size() - 1;

                    if (myString==null||myString.size()==0){
                        myString = new ArrayList<String>();
                        Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                        Collections.shuffle(myString);
                    }
                    String q = myString.remove(0);
                    Text_View.setText(q);

                    for (int i=0;i<myString.size();i++) {
                        random.add(q);
                    }
                }
            });

            prev.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                    Text_View.setText(random.get(counter));
                    counter--;

                }
            });

更新2

我做了新的改变。即使我按了一次以上按钮，该按钮仍可正常工作，但仍然，每次只有第一个显示的元素。新代码是：

public class MyActivity extends Activity {

public int counter;

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

       Text_View.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {

                    Resources res = getResources();

                    if (myString==null||myString.size()==0){
                        myString = new ArrayList<String>();
                        Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                        Collections.shuffle(myString);
                    }
                    String q = myString.remove(0);
                    Text_View.setText(q);

                    for (int i=0;i<myString.size();i++) {
                        random.add(q);
                    }
                }
            });

            prev.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {

                   int counter = myString.size() - 2;

                    if (counter>=0){

                    Text_View.setText(random.get(counter));
                    counter--;

                }

抱歉，我不知道如何使用控制台..

Answer 1

将第二次更新更改为此

public class MyActivity extends Activity {

public int counter;
private static final String TAG = "whatever"; 

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

       Text_View.setOnClickListener(new View.OnClickListener() {
          @Override
          public void onClick(View v) {

                    Resources res = getResources();

                    if (myString==null||myString.size()==0){
                        myString = new ArrayList<String>();
                        Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                        Collections.shuffle(myString);
                        counter = myString.size() - 2;

                    }
                    String q = myString.remove(0);
                    Text_View.setText(q);

                    for (int i=0;i<myString.size();i++) {
                        random.add(q);
                    }
                }
            });

            prev.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {


                    if (counter>=0){
                    Log.i(TAG,Integer.toString(counter));
                    Text_View.setText(random.get(counter));
                    counter--;

                }

将您的手机连接到您的计算机，打开Android显示器，运行应用程序并搜索（它有一个搜索栏）您的标签（此处称为无论如何）。它会过滤结果，所以在这里发布它们。还要告诉我Text_array中有多少项，你点击text_View多少次以及prev多少次。例如，当你先按textview 3（或更多）时会发生什么？

我要睡觉了，早上见到你

编辑1：这应该有效，我创建了一个项目来测试它，它适用于我

public class MyActivity extends Activity {

    public int counter;
    private static final String TAG = "whatever";
    ArrayList <String> myString=null;
    private TextView Text_View;
    private Button prev;
    public ArrayList<String> random=new ArrayList<String>();


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.family_excuses);
        Text_View = (TextView) findViewById(R.id.Text_View);
        prev = (Button) findViewById(R.id.button);//request location

        Text_View.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Resources res = getResources();

                if (myString==null||myString.size()==0){
                    myString = new ArrayList<String>();
                    Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                    Collections.shuffle(myString);

                }
                String q = myString.remove(0);
                Text_View.setText(q);

                    random.add(q);
                counter=random.size()-2;

            }
        });

        prev.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if (counter >= 0) {

                    Text_View.setText(random.get(counter));
                    counter--;

                }
            }
        });
    }
}

唯一的问题应该是，如果你按textview＆gt; prev＆gt; textview它不起作用，但我们也会修复它，我只是想确保它也适合你

编辑2：这应该是最终版本，这适用于textview＆gt; prev＆gt; textview。我不确定该行应该是mark = counter + 2;，随意更改号码，因为我仍然对你要做的事情感到困惑

public class MyActivity extends Activity {

    public int counter;
    private static final String TAG = "whatever";
    ArrayList <String> myString=null;
    private TextView Text_View;
    private Button prev;
    private int mark=-1;
    public ArrayList<String> random=new ArrayList<String>();


    @Override
    protected void onCreate(@Nullable Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.family_excuses);
        Text_View = (TextView) findViewById(R.id.Text_View);
        prev = (Button) findViewById(R.id.button);//request location

        Text_View.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                Resources res = getResources();

                if (myString==null||myString.size()==0){
                    myString = new ArrayList<String>();
                    Collections.addAll(myString,res.getStringArray(R.array.Text_array));
                    Collections.shuffle(myString);

                }
                String q = myString.remove(0);
                Text_View.setText(q);
                Log.i(TAG,Integer.toString(mark));
                if (mark==-1){

                    random.add(q);

                }else {
                    random.add(mark,q);
                }
                counter=random.size()-2;

            }
        });

        prev.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {


                if (counter >= 0) {

                    Text_View.setText(random.get(counter));
                    counter--;
                    mark=counter+2;

                }
            }
        });
    }
}

Answer 2

我认为你应该改变Text_View.setText（q）; 到Text_View.append（q）; 编辑：改为：

prev.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {

                    Text_View.setText(random.get(counter));
                counter--;
            }
        });

在Text_View.setOnClickListener

中为计数器赋值

counter = myString.size() - 1;

并使用全局变量对其进行初始化，例如

public class yourActivity extends AppCompatActivity {

public int counter;

编辑2为您的原始答案添加延迟

    prev.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
private Handler mHandler = new Handler();

                    for (int counter = myString.size() - 1; counter >= 0; counter--) {
                        mHandler.postDelayed(new Runnable() {
            public void run() {
                doStuff(random.get(i));
            }
        }, 5000);

                    }
                }
            });

    private void doStuff(String i) {
    Text_View.setText(i);
    }

并将处理程序添加到导入的库

Android显示向后数组列表元素

2 个答案: