如何通过单击android中的列表视图打开图像？

Posted 2023-04-19

【中文标题】如何通过单击android中的列表视图打开图像？

【英文标题】：How do i open an image by clicking on a listview in android?

【发布时间】：2015-10-30 08:26:35

【问题描述】：

所以，事情就是这样。我想尝试一下。所以，我编写了这个程序，它在我的 GennyMotion 模拟器的 mnt/shared/Newpictures 文件夹中查找扩展名为 (.jpg) 的图像。在我的程序中，我在字符串数组适配器中捕获了扩展名为 .jpg 的文件的名称，并在文件路径字符串数组中捕获了文件路径。现在，这是我空白的部分，我有路径，名称，我可以通过单击列表来获取位置。但是当我单击列表时如何打开图像。我在网上查了一下，大部分代码都太混乱了。所以，可能有人可以建议我一个更简单的方法。这是我到目前为止所尝试的。谢谢。

package com.example.user.imageapp;

import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.ListView;

import java.io.File;
import java.util.ArrayList;

/**
 * Created by user on 06-08-2015.
 */


public class Splash extends Activity 
    Button load;
    String s;
    private ListView mainList;
    private String[] FilePathStrings;

    ArrayList<String>filesinFolder = GetFiles("/mnt/shared/NewPictures");



    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
      //  load = (Button)findViewById(R.id.Load);
        mainList = (ListView) findViewById(R.id.imagelist);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1,filesinFolder );

        mainList.setAdapter(adapter);

        mainList.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            @Override
            public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) 
              //what do i put here


            
        );




    


    public ArrayList<String> GetFiles(String DirectoryPath)
    
        ArrayList<String> MyFiles = new ArrayList<String>();
        File f = new File(DirectoryPath);
        f.mkdirs();

        File[] files = f.listFiles();

        FilePathStrings = new String[files.length];

        for (int i = 0; i < files.length; i++) 
            // Get the path of the image file
            if(files[i].getName().contains(".jpg")) 
                FilePathStrings[i] = files[i].getAbsolutePath();
                // Get the name image file
                MyFiles.add(files[i].getName());

            
        



        return MyFiles;


    

【参考方案1】：

实现此目的的一种简单方法是创建一个包含 imageview 的对话框，然后将 imageview 的图像设置到文件中。像这样的东西应该可以完成这项工作：

public void onItemclick(AdapterView<?> adapterView, View view, int pos, long id)
    String filePath = filesInFolder.get(pos);
    AlertDialog.Builder builder = new AlertDialog.Builder(this);
    LayoutInflater inflater = getLayoutInflater();
    View view = inflater.inflate(R.layout.dialog_img_preview, null);
    builder.setView(view);
    ImageView imgView = (ImageView)view.findViewById(R.id.preview_imgview);
    imgView.setImageBitmap(BitmapFactory.decodeFile(filePath));
    AlertDialog dialog = builder.create();
    dialog.show();

【参考方案2】：

这里是一个简单的例子，你可以通过点击gridview查看图像，但你可以在xml文件中更改为listview。

这是gridview显示。

GridViewActivity.java

public class GridViewActivity extends Activity 

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

        GridView gridview = (GridView) findViewById(R.id.gridview);
        gridview.setAdapter(new ImageAdapter(GridViewActivity.this));

        gridview.setOnItemClickListener(new AdapterView.OnItemClickListener() 
            public void onItemClick(AdapterView<?> parent, View v, int position, long id) 
                // Send intent to SingleViewActivity
                Intent i = new Intent(getApplicationContext(), SingleViewActivity.class);

                // Pass image index
                i.putExtra("id", position);
                startActivity(i);
            
        );
    

该类将在单页中显示图像。

SingleViewActivity.java

public class SingleViewActivity extends Activity 

    ImageLoader imageLoader = ImageLoader.getInstance();
    private DisplayImageOptions options;

    @Override
    public void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.single_view);

        options = new DisplayImageOptions.Builder().cacheInMemory(true)
                .cacheOnDisk(true).considerExifParams(true)
                .showImageForEmptyUri(R.mipmap.ic_launcher)
                .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2)
                .bitmapConfig(Bitmap.Config.RGB_565).build();

        // Get intent data
        Intent i = getIntent();

        // Selected image id
        int position = i.getExtras().getInt("id");
        ImageAdapter imageAdapter = new ImageAdapter(this);

        ImageView imageView = (ImageView) findViewById(R.id.SingleView);
        //imageView.setImageResource(imageAdapter.mThumbnames[position]);
        imageLoader.displayImage(imageAdapter.mThumbnames[position],imageView,options);
    

我使用了一些来自互联网的随机图片。列表视图中使用相同的概念来显示图像。

ImageAdapter.java

public class ImageAdapter extends BaseAdapter 

    private Context mContext;
    private LayoutInflater layoutInflater;
    ImageLoader imageLoader = ImageLoader.getInstance();
    private DisplayImageOptions options;

    // Constructor
    public ImageAdapter(Context c) 
        mContext = c;
        layoutInflater = LayoutInflater.from(mContext);
        options = new DisplayImageOptions.Builder().cacheInMemory(true)
                .cacheOnDisk(true).considerExifParams(true)
                .showImageForEmptyUri(R.mipmap.ic_launcher)
                .imageScaleType(ImageScaleType.IN_SAMPLE_POWER_OF_2)
                .bitmapConfig(Bitmap.Config.RGB_565).build();
    

    public int getCount() 
        return mThumbnames.length;
    

    public Integer getItem(int position) 
        return position;
    

    public long getItemId(int position) 
        return position;
    

    @Override
    public View getView(int position, View convertView, ViewGroup parent) 

        ViewHolder1 holder;
        if (convertView == null) 
            convertView = layoutInflater.inflate(R.layout.grideview_item, null);
            holder = new ViewHolder1();
            holder.image = (ImageView) convertView.findViewById(R.id.imageView);
            convertView.setTag(holder);
         else 
            holder = (ViewHolder1) convertView.getTag();
        


        // Load image, decode it to Bitmap and display Bitmap in ImageView (or any other view
        //  which implements ImageAware interface)

        //imageLoader.displayImage("drawable://" + mThumbIds[position], holder.image);
        imageLoader.displayImage(mThumbnames[position], holder.image, options);
        //holder.image.setImageDrawable(mContext.getResources().getDrawable(mThumbIds[position]));
        return convertView;
    

    public static class ViewHolder1 
        ImageView image;
    

    // Keep all Images in array
   /* public Integer[] mThumbIds = 
            R.drawable.ab, R.drawable.ac,
            R.drawable.ad, R.drawable.ae

    ;*/
    public String[] mThumbnames = 
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg",
            "http://cdn2.ubergizmo.com/wp-content/uploads/2012/05/android_lock.jpg"

    ;

gridview_item.xml

    <?xml version="1.0" encoding="utf-8"?>
    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_
    android:layout_
    android:layout_gravity="center_horizontal">

    <ImageView
        android:id="@+id/imageView"
        android:layout_
        android:layout_
        android:layout_gravity="left"
        android:paddingBottom="5dp"
        android:paddingLeft="5dp"
        android:paddingRight="5dp"
        android:paddingTop="10dp"
        android:scaleType="fitXY" />

    <TextView
        android:id="@+id/textView2"
        android:layout_
        android:layout_
        android:layout_gravity="center|bottom"
        android:layout_marginBottom="5dip"
        android:background="#80000000"
        android:gravity="center"
        android:text="images"
        android:textColor="#000000"
        android:textSize="20dp" />
</FrameLayout>