Question

I have some images stored in getExternalFilesDir() and i am trying to show those images in the android gallery (cooliris). Right now i have been doing this:

Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(Uri.fromFile(imgPath,"image/*");
startActivity(intent);

But nothing happens. I have changed the setDataAndType to this:

intent.setDataAndType(Uri.fromFile(new File(imgPath)),"image/*");

但画廊需要5到10秒从黑屏幕上展示我的形象

不管怎么说,解决这个还是更好的方法?

Answer 1

通过实施文件内容提供者, 您可以避免5- 10 第二次延迟。

import java.io.File;
import java.io.FileNotFoundException;

import android.content.ContentProvider;
import android.content.ContentValues;
import android.database.Cursor;
import android.net.Uri;
import android.os.ParcelFileDescriptor;

public class FileContentProvider extends ContentProvider {
    private static final String AUTHORITY = "content://com.yourprojectinfo.fileprovider";

    public static Uri constructUri(String url) {
        Uri uri = Uri.parse(url);
        return uri.isAbsolute() ? uri : Uri.parse(AUTHORITY + url);
    }

    public static Uri constructUri(File file) {
        Uri uri = Uri.parse(file.getAbsolutePath());
        return uri.isAbsolute() ? uri : Uri.parse(AUTHORITY
                + file.getAbsolutePath());
    }

    @Override
    public ParcelFileDescriptor openFile(Uri uri, String mode)
            throws FileNotFoundException {
        File file = new File(uri.getPath());
        ParcelFileDescriptor parcel = ParcelFileDescriptor.open(file,
                ParcelFileDescriptor.MODE_READ_ONLY);
        return parcel;
    }

    @Override
    public boolean onCreate() {
        return true;
    }

    @Override
    public int delete(Uri uri, String s, String[] as) {
        throw new UnsupportedOperationException(
                "Not supported by this provider");
    }

    @Override
    public String getType(Uri uri) {
        return "image/jpeg";
    }

    @Override
    public Uri insert(Uri uri, ContentValues contentvalues) {
        throw new UnsupportedOperationException(
                "Not supported by this provider");
    }

    @Override
    public Cursor query(Uri uri, String[] as, String s, String[] as1, String s1) {
        throw new UnsupportedOperationException(
                "Not supported by this provider");
    }

    @Override
    public int update(Uri uri, ContentValues contentvalues, String s,
            String[] as) {
        throw new UnsupportedOperationException(
                "Not supported by this provider");
    }

}

然后你可以打电话

Uri uri = FileContentProvider.constructUri(file);
Intent intent = new Intent();
intent.setAction(android.content.Intent.ACTION_VIEW);
intent.setDataAndType(uri,"image/*");
startActivity(intent);

这是一个奇怪的变通方法, 但我认为它和机器人如何使用 URI 打开图像有关。它们的开放式File( Uri uri, string 模式) 方法是错误的 / 折断 / 无法正确解决 URI 。虽然我并不完全确定, 但我发现这种变通方法是有效的。

请勿忘记在货单上向提供商登记。

友情链接