从SQLite读取图片URI无法加载问题求助（硬编码可正常显示）

Let's get straight to fixing your image display issue— the problem is hiding in your monitorData() method!

The Root Cause #

Take a look at how you're adding URIs to your list:

public String monitorData() { 
    ArrayList<String> listData = new ArrayList<>(); 
    Cursor data = mDatabaseHelper.getData(); 
    while(data.moveToNext()){ 
        // You're prepending a newline character to the URI here!
        listData.add("\n" + data.getString(1)); 
    } 
    return listData.get(0); 
}

When you call Uri.parse(monitorData()), you're trying to parse a string like "\ncontent://media/external/images/media/47" instead of a clean, valid URI. That extra \n breaks the URI format, which is exactly why you see the resolveUri failed on bad bitmap uri error.

The Quick Fix #

Remove the unnecessary newline character when adding the URI to your list:

public String monitorData() { 
    ArrayList<String> listData = new ArrayList<>(); 
    Cursor data = mDatabaseHelper.getData(); 
    while(data.moveToNext()){ 
        // Add the raw URI without the newline
        listData.add(data.getString(1)); 
    } 
    // Add a safety check to avoid crashes if the database has no data
    return listData.isEmpty() ? null : listData.get(0); 
}

Then update your image loading code to handle potential empty results:

String uriString = monitorData();
if (uriString != null) {
    mImageView.setImageURI(Uri.parse(uriString));
}

Extra Best Practices to Avoid Future Issues #

1. Close Your Cursor Properly: Leaving a Cursor open can cause memory leaks. Modify your monitorData() method to clean up:

public String monitorData() { 
    ArrayList<String> listData = new ArrayList<>(); 
    Cursor data = mDatabaseHelper.getData(); 
    try {
        while(data.moveToNext()){ 
            listData.add(data.getString(1)); 
        }
    } finally {
        // Always close the cursor when you're done with it
        if (data != null) {
            data.close();
        }
    }
    return listData.isEmpty() ? null : listData.get(0); 
}

2. Validate URIs: If you're ever unsure about a URI string, add a quick check to confirm it's valid before parsing:

if (uriString != null && Uri.parse(uriString).isAbsolute()) {
    mImageView.setImageURI(Uri.parse(uriString));
}

That should get your images showing up as expected!

内容的提问来源于stack exchange，提问作者FUNYA 1337