在Android中获取选定的图像文件位置 [英] Get Selected Image File Location in Android

问题描述

我正在制作一个适用于图片的应用程序。我需要在用户选择存储在SD卡上的文件时实现功能。一旦他们选择了图片（使用Android图库），图像的文件位置将被发送到另一个活动，在那里做其他工作。

我在这里看过类似的帖子，但没有专门回答我的问题。基本上这是我用户点击加载图片按钮时所做的代码：

  //创建一个新的Intent打开图片选择器：
 Intent loadPicture = new Intent（Intent.ACTION_PICK，android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI）; 
 
 //启动它，运行startActivityForResult（）方法：
 startActivityForResult（loadPicture，SELECT_IMAGE）; 
  

从这段代码，我有一个 onActivityResult（）


  //如果用户试图选择一个图像：
 if（requestCode == SELECT_IMAGE）
 {
 //检查用户是否真的选择了一个图像：
 if（resultCode == Activity.RESULT_OK）
 {
 //获得用户选择的图像的URI：
 Uri selectedImage = data.getData（）; 
 
 //创建一个新的Intent发送到下一个Activity：
 Intent i = new Intent（currentActivty.this，nextActivity.class）; 
 
 // -----------------问题领域----------------- 
 //我想将文件名发送到Intent对象，并发送它。 
 //然而，selectedImage.toString（）方法将返回一个
 //content：//字符串，而不是文件位置。如何从该URI对象获取文件
 //位置？ 
 i.putExtra（PICTURE_LOCATION，selectedImage.toString（））; 
 
 //开始上面的Intent概述的活动：
 startActivity（i）; 
  

如上面的代码所示， uri.toString（）将返回一个 content：// 字符串，而不是所选图片的文件位置。注意：另一种可能的解决方案是通过 content：// 来发送文件位置。字符串并将其转换为位图（这是在下一个活动中发生的情况）。但是，我不知道该怎么做。

解决方案

我已经找到了自己的问题的答案。在做了一些更多的搜索之后，我终于在这里发现了一个帖子，在这里提出了同样的问题： android通过Uri.getPath（）获取真正的路径。



不幸的是，答案有一个断开的链接。经过一番Google搜索，我发现这里的网站链接正确： http：//www.androidsnippets。 org / snippets / 130 / （我已经验证过这段代码确实有效。）



然而，我决定采取不同的路线。由于我的下一个Activity正在使用 ImageView 来显示图片，我将使用Uri内容字符串来链接到下一个Activity的所有方法。

在下一个Activity中，我使用 ImageView.setImageUri（）方法。
$ b

下面是我在下一个活动中的代码，显示来自 content：// 字符串的图片：

  //从前面的Activity获取内容字符串：
 picLocation = getIntent（）。getStringExtra（PICTURE_LOCATION）; 
 
 //实例化ImageView对象：
 ImageView imageViewer =（ImageView）findViewById（R.id.ImageViewer）; 
 
 //将Uri字符串转换为可用的Uri：
 Uri temp = Uri.parse（picLocation）; 
 imageViewer.setImageURI（temp）; 
  

我希望这个问题和答案对未来的Android开发者有帮助。 $ b

I am currently making an app which works with images. I need to implement functionality where the user picks a file stored on the SD card. Once they pick the picture (using the Android gallery), the the file-location of the image will be sent to another Activity, where other work will be done upon it.

I have seen similar posts here on SO, but none to answer my question specifically. Basically this is the code I am doing when the user clicks the "Load a Picture" button:

// Create a new Intent to open the picture selector:
Intent loadPicture = new Intent(Intent.ACTION_PICK, android.provider.MediaStore.Images.Media.EXTERNAL_CONTENT_URI);

// To start it, run the startActivityForResult() method:
startActivityForResult(loadPicture, SELECT_IMAGE);

From that code, I then have a onActivityResult() method to listen to the call-back:

// If the user tried to select an image:
if(requestCode == SELECT_IMAGE)
{
    // Check if the user actually selected an image:
    if(resultCode == Activity.RESULT_OK)
    {
        // This gets the URI of the image the user selected:
        Uri selectedImage = data.getData();

        // Create a new Intent to send to the next Activity:
        Intent i = new Intent(currentActivty.this, nextActivity.class);

        // ----------------- Problem Area -----------------
        // I would like to send the filename to the Intent object, and send it over.
        // However, the selectedImage.toString() method will return a
        // "content://" string instead of a file location.  How do I get a file
        // location from that URI object?
        i.putExtra("PICTURE_LOCATION", selectedImage.toString());

        // Start the activity outlined with the Intent above:
        startActivity(i);

As the code above states, the uri.toString() will return a content:// string instead of the file location of the selected picture. How do I obtain the file location?

Note: Another possible solution is to send over the content:// string and convert that into a Bitmap (which is what happens in the next Activity). However, I don't know how to do that.

解决方案

I have found the answer to my own question. After doing some more searching, I finally stumbled upon a post here on SO which asks the same question here: android get real path by Uri.getPath().

Unfortunately, the answer has a broken link. After some Google searching, I found the correct link to the site here: http://www.androidsnippets.org/snippets/130/ (I have verified that this code does indeed work.)

However, I decided to take a different route. Since my next Activity is using an ImageView to display the picture, I am instead going to use the Uri content string for all methods that link to the next Activity.

In the next Activity, I am using the ImageView.setImageUri() method.

Here is the code I am doing in the next Activity to display the picture from the content:// string:

// Get the content string from the previous Activity:
picLocation = getIntent().getStringExtra("PICTURE_LOCATION");

// Instantiate the ImageView object:
ImageView imageViewer = (ImageView)findViewById(R.id.ImageViewer);

// Convert the Uri string into a usable Uri:
Uri temp = Uri.parse(picLocation);
imageViewer.setImageURI(temp);

I hope that this question and answer will be helpful to future Android developers.

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