Question

我正在使用此代码加载本地sqlite数据库。

- (id)init
{
    self = [super init];
    if (self) {
        NSString *path = [[NSBundle mainBundle] pathForResource:@"db" ofType:@"sqlite3"];
        _db = [[MDDatabase alloc] initWithPath:path];
        _HTMLRenderer = [[MDHTMLRenderer alloc] init];
    }
    return self;
}

我想将数据库放在网上，让应用程序下载数据库。我将代码更改为：

NSData *dbFile = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://www.someurl.com/DatabaseName.sqlite"]];

        NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle]  resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];

        NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"Database.sqlite"];

        [dbFile writeToFile:filePath atomically:YES];
        _db = [[MDDatabase alloc] initWithPath:filePath];
        _HTMLRenderer = [[MDHTMLRenderer alloc] init];

Editted：我改变了我的代码，但它已经崩溃了。

- (id)init
{
    self = [super init];
    if (self) {
        [self performSelectorOnMainThread:@selector(downalod) withObject:nil waitUntilDone:YES];
        NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle]  resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];

        NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"Database.sqlite"];
        _db = [[MDDatabase alloc] initWithPath:filePath];
        _HTMLRenderer = [[MDHTMLRenderer alloc] init];
    }
    return self;
}

-(void)download
{

    NSData *dbFile = [[NSData alloc] initWithContentsOfURL:[NSURL URLWithString:@"http://www.someurl.com/DatabaseName.sqlite"]];

    NSString *resourceDocPath = [[NSString alloc] initWithString:[[[[NSBundle mainBundle]  resourcePath] stringByDeletingLastPathComponent] stringByAppendingPathComponent:@"Documents"]];

    NSString *filePath = [resourceDocPath stringByAppendingPathComponent:@"Database.sqlite"];

    [dbFile writeToFile:filePath atomically:YES];
}

Answer 1

您的文件存在问题。检查正确的网址。它是一个编码问题。试试这个（它会起作用）：http://spaceflight.nasa.gov/gallery/images/apollo/apollo17/hires/s72-55482.jpg
在plist中添加App Transport Security设置（允许任意加载YES）。
启用后台模式。

在.m

中声明此宏

#define DocumentsDirectory [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) objectAtIndex:0]

现在打电话，您将在本地获得该文件。

请致电：

[self performSelectorOnMainThread:@selector(downalod) withObject:nil waitUntilDone:NO];

  _db = [[MDDatabase alloc] initWithPath:filePath];
    _HTMLRenderer = [[MDHTMLRenderer alloc] init];

 -(void)download
 {

    NSString *stringURL =[NSString stringWithFormat: @"url"];
NSURL *url = [NSURL URLWithString:[NSString stringWithFormat:@"%@",[stringURL stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]]];
NSURLRequest *urlRequest = [NSURLRequest requestWithURL:url];
NSOperationQueue *queue = [[NSOperationQueue alloc] init];

NSString *filePath = [DocumentsDirectory stringByAppendingPathComponent:[url lastPathComponent]];
NSLog(@"success--222,%@", filePath);

[NSURLConnection sendAsynchronousRequest:urlRequest queue:queue completionHandler:^(NSURLResponse *response, NSData *data, NSError *error)
{

    NSLog(@"success--222,%@", filePath);


    if (error)
    {
        NSLog(@"success--not---Error,%@", [error localizedDescription]);
    }
    else
    {
        NSLog(@"success--yes... %@", [[NSString alloc] initWithData:data encoding:NSASCIIStringEncoding]);

        [data writeToFile:filePath atomically:YES];

    }
}];
 }

Answer 2

经过长时间的搜索，终于我自己解决了这个问题：

- (id)init
{
    self = [super init];
    if (self) {
        NSData *fetchedData = [NSData dataWithContentsOfURL:[NSURL URLWithString:@"http://www.someurl.com/db.sqlite3"]];
        NSString *documentsPath = [NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES) lastObject];
        NSString *filePath = [documentsPath stringByAppendingPathComponent:@"db.sqlite3"];
        [fetchedData writeToFile:filePath atomically:YES];
        _db = [[MDDatabase alloc] initWithPath:filePath];
        _HTMLRenderer = [[MDHTMLRenderer alloc] init];
    }
    return self;
}

从URL下载sqlite数据库

2 个答案: