Question

我不想添加一个sqlite文件来为我的应用程序预加载数据。我创建了这个文件并将其复制到项目目录中。我将它添加到Copy Bundle Resources并复制文件。但是，当我不想使用这个文件时，我得到一个错误，说没有这样的文件。如果有人能帮助我，我将不胜感激。代码如下：

NSURL *preloadURL = [NSURL fileURLWithPath:[[NSBundle mainBundle] pathForResource:@"CookBookData" ofType:@"sqlite"]] ;

if (![[NSFileManager defaultManager] copyItemAtURL:preloadURL toURL:storeURL error:&error]) {
    NSLog(@"Couldn't preload data, error: %@", error);
}

错误：

2015-07-29 15：42：34.342 CookBook v1 [2897：24912]无法预加载数据，错误：错误Domain = NSCocoaErrorDomain Code = 4“操作无法完成。（Cocoa错误4.） “UserInfo = 0x7fe4a35275d0 {NSSourceFilePathErrorKey = / Users / user / Library / Developer / CoreSimulator / Devices /.../ data / Containers / Bundle / Application /.../ CookBook v1.app/CookBookData.sqlite,NSUserStringVariant =（复制），NSDestinationFilePath = / Users / user / Library / Developer / CoreSimulator / Devices /.../ Documents / CookBookModel 2.sqlite，NSFilePath = / Users / user / Library / Developer / CoreSimulator / Devices /.../ data / Containers /Bundle/Application/.../CookBook v1.app/CookBookData.sqlite,NSUnderlyingError = 0x7fe4a35145d0“操作无法完成。没有这样的文件或目录”}

我试图更改我的代码：

NSURL *storeURL = [[self applicationDocumentsDirectory] URLByAppendingPathComponent:@"CookBookModel3.sqlite"];
NSError *error = nil;

NSString *storePath = [storeURL path];
NSLog(@"Error %@", error);

NSString *dbName = @"CookBookData.sqlite";
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
NSString *dbPath = [documentDirectory stringByAppendingString:dbName];

BOOL success = [fileManager fileExistsAtPath:dbPath];
if (!success) {
    NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:dbName];
    success = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error];
    if (success) {
        NSLog(@"Success");
    }
    else{
        NSLog(@"Error %@", [error localizedDescription]);
    }
}
else {
    NSLog(@"Already exists");
}

if (![[NSFileManager defaultManager] copyItemAtPath:dbPath toPath:storePath error:&error]) {
    NSLog(@"Couldn't preload data, error: %@", error);
}

但我得到另一个错误：

2015-07-30 12：12：29.118 CookBook [29209：208802]无法预加载数据，错误：错误Domain = NSCocoaErrorDomain Code = 516“操作无法完成。（Cocoa error 516.）” UserInfo = 0x7fe9526318b0 {NSSourceFilePathErrorKey = / Users / user / Library / Developer / CoreSimulator / Devices / DA5D105A-C9AF-4C91-80B3-DFF2C157CC92 / data / Containers / Data / Application / BEED2AB9-BFDA-40AC-A8D0-55DD81F9D985 / Library / DocumentationCookBookData .sqlite，NSUserStringVariant =（复制），NSDestinationFilePath = / Users / user / Library / Developer / CoreSimulator / Devices / DA5D105A-C9AF-4C91-80B3-DFF2C157CC92 / data / Containers / Data / Application / BEED2AB9-BFDA-40AC-A8D0-55DD81F9D985 / Documents / CookBookModel3.sqlite ，NSFilePath = / Users / user / Library / Developer / CoreSimulator / Devices / DA5D105A-C9AF-4C91-80B3-DFF2C157CC92 / data / Containers / Data / Application / BEED2AB9-BFDA-40AC-A8D0-55DD81F9D985 / Library / DocumentationCookBookData.sqlite， NSUnderlyingError = 0x7fe952610c30“操作无法完成。文件存在”} 2015-07-30 12：12：29.121 CookBook [29209：208802]托管对象上下文

另一种变体：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
NSString *path = [documentsDir stringByAppendingPathComponent:@"CookBookData.sqlite"]; 
NSFileManager *fileManager = [NSFileManager defaultManager];
[fileManager copyItemAtPath:path toPath:storePath error:&error];

Answer 1

使用以下内容获取相关文件的路径：

NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory , NSUserDomainMask, YES);
NSString *documentsDir = [paths objectAtIndex:0];
NSString *path = [documentsDir stringByAppendingPathComponent:@"CookBookData.sqlite"];

然后，您可以使用以下内容复制文件：

NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:@"database.sqlite"];
[fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error];

我会包含比上面更多的检查和验证 - 特别是NSFileManager中的fileExistsAtPath:方法。

Answer 2

我希望，这会有所帮助：

NSError *error;
NSString *dbName = @"CookBookData.sqlite";
NSFileManager *fileManager = [NSFileManager defaultManager];
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentationDirectory, NSUserDomainMask, YES);
NSString *documentDirectory = [paths objectAtIndex:0];
NSString *dbPath = [documentDirectory stringByAppendingString:dbName];
NSString *defaultDBPath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent:dbName];

if ([fileManager fileExistsAtPath:defaultDBPath]) { //check if file exists in NSBundle

    BOOL success = [fileManager fileExistsAtPath:dbPath]; // check if exists in document directory
    if (!success) {

        success = [fileManager copyItemAtPath:defaultDBPath toPath:dbPath error:&error]; //copy to document directory
        if (success) {
            NSLog(@"Database successfully copied to document directory");
        }
        else{
            NSLog(@"Error %@", [error localizedDescription]);
        }
    }
    else {
        NSLog(@"Already exists in document directory");
    }

}
else{
    NSLog(@"Does not exists in NSBundle");
}

您可以检查两件事，转到您的应用程序文档目录，检查是否可以去那里，其他事情是确保您的sqlite文件已正确添加到项目中，您可以删除并再次添加。让我知道，如果还有问题

添加sqlite数据库：没有这样的文件或目录

2 个答案: