Android Listview 从字符串中加载图片点击

Question

我有一个项目列表，单击新列表后 activity 打开并显示详细信息。问题是我无法执行 - 单击详细 activity 中的特定字符串后加载图像。比如在MainActivity中，有：

String one[] = {"dog", "cat", "horse", "snail"};
String two[] = {"aaa", "bbb", "ccc", "ddd"};
String three[] = {"111", "**222**", "333", "**222**"};

打开应用程序，单击第二个列表项 (cat) 并打开新的 activity 以及详细信息（cat 的所有字符串）在这种情况下，我需要在单击“字符串三”之后 - 如果字符串是 222，打开图像 (drawable/222.jpg)，在这种情况下是“猫”和“蜗牛”。点击“333”后显示图片 333.jpg ...

如果可以的话，最好用后退按钮打开图片，返回到详细内容activity。

简化的 MainActivity：

String one[] = {"dog", "cat", "horse", "snail"};
String two[] = {"aaa", "bbb", "ccc", "ddd"};
String three[] = {"111", "222", "333", "222"};



List<ItemsModel> itemsModelList = new ArrayList<>();

ListView listView;

CustomAdapter customAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    setContentView(R.layout.activity_main);
    listView = findViewById(R.id.listview);


    for(int i = 0;i < one.length;i++){

        ItemsModel itemsModel = new ItemsModel(one[i],two[i],three[i]);

        itemsModelList.add(itemsModel);

    }

    customAdapter = new CustomAdapter(itemsModelList,this);

    listView.setAdapter(customAdapter);


}


@Override
public boolean onOptionsItemSelected(@NonNull MenuItem item) {

    int id = item.getItemId();


    if(id == R.id.searchView){

        return true;
    }
    return super.onOptionsItemSelected(item);
}


public class CustomAdapter extends BaseAdapter implements Filterable {

    private List<ItemsModel> itemsModelsl;
    private List<ItemsModel> itemsModelListFiltered;
    private Context context;

    public CustomAdapter(List<ItemsModel> itemsModelsl, Context context) {
        this.itemsModelsl = itemsModelsl;
        this.itemsModelListFiltered = itemsModelsl;
        this.context = context;
    }



    @Override
    public int getCount() {
        return itemsModelListFiltered.size();
    }

    @Override
    public Object getItem(int position) {
        return itemsModelListFiltered.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(final int position, View convertView, ViewGroup parent) {
        View view = getLayoutInflater().inflate(R.layout.row_items,null);


        TextView one = view.findViewById(R.id.one);
        TextView two = view.findViewById(R.id.two);

        one.setText(itemsModelListFiltered.get(position).getone());
        two.setText(itemsModelListFiltered.get(position).gettwo());

        view.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Log.e("main activity","item clicked");
                startActivity(new Intent(MainActivity.this, ItemsActivity.class).putExtra("items",itemsModelListFiltered.get(position)));

            }
        });

        return view;
    }

//// 物品模型：

public class ItemsModel implements Serializable {

    private String one;
    private String two;
    private String three;

    public ItemsModel(String one, String two, String three) {
        this.one = one;
        this.two = two;
        this.three = three;

    }

    public String getone() {
        return one;
    }

    public void setone(String one) {
        this.one = one;
    }

    public String gettwo() {return two; }

    public void settwo(String two) { this.two = two; }

    public String getthree() {return three; }

    public void setthree(String three) { this.three = three; }

///

如果你需要Itemactivity或activity.xml我会复制

Answer 1

对于res/drawable文件夹中的文件，文件名不能以数字开头，如111.jpg、222.jpg等。为此你可以添加一个以 image_111.jpg、image_222.jpg 等字母开头的前缀。

解决方案

在ItemsActivity中，使用getIdentifier(String, String, String)通过资源名称（image_222）获取资源ID（R.drawable.image_222）。

public class ItemActivity extends AppCompatActivity  {

    TextView textView;
    TextView textView2;
    TextView textView3;

    ItemsModel itemsModel;

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

        textView = findViewById(R.id.textView);
        textView2 = findViewById(R.id.textView2);
        textView3 = findViewById(R.id.textView3);

        Intent intent = getIntent();
        if (intent.getExtras() != null) {
            itemsModel = (ItemsModel) intent.getSerializableExtra("items");
            textView2.setText(itemsModel.getone());
            textView.setText(itemsModel.gettwo());
            textView3.setText(itemsModel.getthree());
            textView3.setClickable(true);
            textView3.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View v) {
                    // Get drawable name
                    String drawableName = "image_" + itemsModel.getthree();

                    // Find drawable resource id by drawable name
                    int drawableResId = getResources().getIdentifier(
                            drawableName,
                            "drawable",
                            getPackageName());

                    showImageDetail(drawableResId);
                }
            });
        }
    }

    private void showImageDetail(int imageResId) {
        // Using a dialog or activity to open image detail.
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        ImageView imageView = new ImageView(this);
        imageView.setImageResource(imageResId);
        builder.setView(imageView);
        builder.create().show();
    }
}

更新

First issue is recognition of "222" when String three[] is for example "xxx & 222", so I need recognition of "222" inside hole string. Some bigger string will have both 222 and 333 inside, can I click on both? One will show image_222 other image_333.

这有点复杂。例如，three 值可能是

333 yyy 444 xxx & 222

在这种情况下，您必须循环遍历字符串并找到图像编号，如 333、444、222，并计算其开始和结束索引，然后使用 SpannableStringBuilder.setSpan() 方法为每个设置点击监听器图片编号.

在下面的代码中，我将使用

Java Regex 查找 three 值中的所有图像编号。
SpannableStringBuilder.setSpan() 设置图片编号点击监听器的方法。

代码

public class ItemsActivity extends AppCompatActivity {

    TextView textView;
    TextView textView2;
    TextView textView3;

    ItemsModel itemsModel;

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

        textView = findViewById(R.id.textView);
        textView2 = findViewById(R.id.textView2);
        textView3 = findViewById(R.id.textView3);

        Intent intent = getIntent();
        if (intent.getExtras() != null) {
            itemsModel = (ItemsModel) intent.getSerializableExtra("items");
            textView.setText(itemsModel.getone());
            textView2.setText(itemsModel.gettwo());

            String three = itemsModel.getthree();
            SpannableStringBuilder builder = new SpannableStringBuilder(three);

            String regex = three;
            Pattern pattern = Pattern.compile("(\d{3})");
            Matcher matcher = pattern.matcher(regex);
            while (matcher.find()) {
                String imageNumber = matcher.group(0);
                int numberStartIndex = three.indexOf(imageNumber);
                int numberEndIndex = numberStartIndex + imageNumber.length();

                builder.setSpan(new ClickableSpan() {
                    @Override
                    public void onClick(@NonNull View widget) {
                        showImageDetailByImageNumber(imageNumber);
                    }
                }, numberStartIndex, numberEndIndex, SpannableStringBuilder.SPAN_EXCLUSIVE_EXCLUSIVE);

                regex = three.substring(numberEndIndex);
                matcher = pattern.matcher(regex);
            }

            textView3.setMovementMethod(LinkMovementMethod.getInstance());
            textView3.setText(builder);
        }
    }

    /**
     * Find the image drawable (image_222.jpg) based on its number name (222)
     * @param imageNumber The image number like 111, 222, 333.
     */
    private void showImageDetailByImageNumber(String imageNumber) {
        // Get drawable name
        String drawableName = "image_" + imageNumber;

        // Find drawable resource id by drawable name
        int drawableResId = getResources().getIdentifier(
                drawableName,
                "drawable",
                getPackageName());

        // Using a dialog or activity to open image detail.
        AlertDialog.Builder builder = new AlertDialog.Builder(this);
        ImageView imageView = new ImageView(this);
        imageView.setImageResource(drawableResId);
        builder.setView(imageView);
        builder.create().show();
    }
}

Second issue is that inside drawable folder image name must have small letters and numbers. I will need with capital letter string (for example A222)

在Android中，drawable里面的文件名必须以小写字母开头，所以我认为你只在那个文件夹中为图像使用前缀，比如image_，img_ 或任何符合您要求的前缀。

Answer 2

好的，我只是做了一个可视化，应该是这样的。

此刻，第一个和第二个 activity 运行正常，仅此而已。现在我需要在代码部分实现第二个 activity，就像我给出的图像一样。当点击“222”（第二个 activity）时，它应该打开 drawable/image_222.jpg 当点击“333”（第二个 activity）时，它应该打开 drawable/image_333.jpg 字符串 222 会出现在几个地方，例如我给 Cat 和 snail。所以如果我理解它应该是这样的：如果“三是”“222”点击显示“可绘制image_222.jpg”（我知道这看起来很糟糕，我只是简化了它）

向下短ItemActivity:

  TextView textView;
TextView textView2;
TextView textView3;

ItemsModel itemsModel;


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


    textView = findViewById(R.id.textView);
    textView2 = findViewById(R.id.textView2);
    textView3 = findViewById(R.id.textView3);


    Intent intent = getIntent();
    if(intent.getExtras() != null){
        itemsModel = (ItemsModel) intent.getSerializableExtra("items");
        textView2.setText(itemsModel.getone());
        textView.setText(itemsModel.gettwo());
        textView3.setText(itemsModel.getthree());


    }

/// https://i.stack.imgur.com/sdyyC.jpg

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