I recently got an example of some code from a friend but he told me one line needs to be changed to make it work for me. Here's the code:
我最近从朋友那里得到了一些代码的例子,但他告诉我需要更改一行以使其适用于我。这是代码:
- (void)tableView:(NSTableView *)aTableView willDisplayCell:(id)aCell forTableColumn:
(NSTableColumn *)aTableColumn row:(int)rowIndex {
if ([aCell respondsToSelector:@selector(setTextColor:)]) {
if ([self visibilityForFile:[fileList objectAtIndex:rowIndex]] == NO)
[aCell setTextColor:[NSColor lightGrayColor]];
else [aCell setTextColor:[NSColor blackColor]];
}
}
I need to replace this line:
我需要替换这一行:
[self visibilityForFile:[fileList objectAtIndex:rowIndex]] == NO
With some different code, what I am actually trying to do is, as I've got a table every row in the table has a checkbox, when a checkbox in a row is checked the text color of that row will change. I think the code needs to check to see if the checkbox in the row is checked, I just need the code for that.
使用一些不同的代码,我实际上要做的是,因为我有一个表,表中的每一行都有一个复选框,当一行中的复选框被选中时,该行的文本颜色将会改变。我认为代码需要检查是否检查了行中的复选框,我只需要代码。
Update
This is the Delegate for The App (Core Data).
这是应用程序的代表(核心数据)。
Header File (.h):
头文件(.h):
#import <Cocoa/Cocoa.h>
@interface Spark_AppDelegate : NSObject
{
IBOutlet NSWindow *window;
IBOutlet NSMenu *theMenu;
NSPersistentStoreCoordinator *persistentStoreCoordinator;
NSManagedObjectModel *managedObjectModel;
NSManagedObjectContext *managedObjectContext;
}
- (NSPersistentStoreCoordinator *)persistentStoreCoordinator;
- (NSManagedObjectModel *)managedObjectModel;
- (NSManagedObjectContext *)managedObjectContext;
- (IBAction)saveAction:sender;
@end
.M file
/**
Returns the support folder for the application, used to store the Core Data
store file. This code uses a folder named "Spark" for
the content, either in the NSApplicationSupportDirectory location or (if the
former cannot be found), the system's temporary directory.
*/
- (NSString *)applicationSupportFolder {
NSArray *paths = NSSearchPathForDirectoriesInDomains(NSApplicationSupportDirectory, NSUserDomainMask, YES);
NSString *basePath = ([paths count] > 0) ? [paths objectAtIndex:0] : NSTemporaryDirectory();
return [basePath stringByAppendingPathComponent:@"Spark"];
}
/**
Creates, retains, and returns the managed object model for the application
by merging all of the models found in the application bundle.
*/
- (NSManagedObjectModel *)managedObjectModel {
if (managedObjectModel != nil) {
return managedObjectModel;
}
managedObjectModel = [[NSManagedObjectModel mergedModelFromBundles:nil] retain];
return managedObjectModel;
}
/**
Returns the persistent store coordinator for the application. This
implementation will create and return a coordinator, having added the
store for the application to it. (The folder for the store is created,
if necessary.)
*/
- (NSPersistentStoreCoordinator *) persistentStoreCoordinator {
if (persistentStoreCoordinator != nil) {
return persistentStoreCoordinator;
}
NSFileManager *fileManager;
NSString *applicationSupportFolder = nil;
NSURL *url;
NSError *error;
fileManager = [NSFileManager defaultManager];
applicationSupportFolder = [self applicationSupportFolder];
if ( ![fileManager fileExistsAtPath:applicationSupportFolder isDirectory:NULL] ) {
[fileManager createDirectoryAtPath:applicationSupportFolder attributes:nil];
}
url = [NSURL fileURLWithPath: [applicationSupportFolder stringByAppendingPathComponent: @"Spark.xml"]];
persistentStoreCoordinator = [[NSPersistentStoreCoordinator alloc] initWithManagedObjectModel: [self managedObjectModel]];
if (![persistentStoreCoordinator addPersistentStoreWithType:NSXMLStoreType configuration:nil URL:url options:nil error:&error]){
[[NSApplication sharedApplication] presentError:error];
}
return persistentStoreCoordinator;
}
/**
Returns the managed object context for the application (which is already
bound to the persistent store coordinator for the application.)
*/
- (NSManagedObjectContext *) managedObjectContext {
if (managedObjectContext != nil) {
return managedObjectContext;
}
NSPersistentStoreCoordinator *coordinator = [self persistentStoreCoordinator];
if (coordinator != nil) {
managedObjectContext = [[NSManagedObjectContext alloc] init];
[managedObjectContext setPersistentStoreCoordinator: coordinator];
}
return managedObjectContext;
}
/**
Returns the NSUndoManager for the application. In this case, the manager
returned is that of the managed object context for the application.
*/
- (NSUndoManager *)windowWillReturnUndoManager:(NSWindow *)window {
return [[self managedObjectContext] undoManager];
}
/**
Performs the save action for the application, which is to send the save:
message to the application's managed object context. Any encountered errors
are presented to the user.
*/
- (IBAction) saveAction:(id)sender {
NSError *error = nil;
if (![[self managedObjectContext] save:&error]) {
[[NSApplication sharedApplication] presentError:error];
}
}
/**
Implementation of the applicationShouldTerminate: method, used here to
handle the saving of changes in the application managed object context
before the application terminates.
*/
- (NSApplicationTerminateReply)applicationShouldTerminate:(NSApplication *)sender {
NSError *error;
int reply = NSTerminateNow;
if (managedObjectContext != nil) {
if ([managedObjectContext commitEditing]) {
if ([managedObjectContext hasChanges] && ![managedObjectContext save:&error]) {
// This error handling simply presents error information in a panel with an
// "Ok" button, which does not include any attempt at error recovery (meaning,
// attempting to fix the error.) As a result, this implementation will
// present the information to the user and then follow up with a panel asking
// if the user wishes to "Quit Anyway", without saving the changes.
// Typically, this process should be altered to include application-specific
// recovery steps.
BOOL errorResult = [[NSApplication sharedApplication] presentError:error];
if (errorResult == YES) {
reply = NSTerminateCancel;
}
else {
int alertReturn = NSRunAlertPanel(nil, @"There Are Un-Saved Changes. Quit anyway?" , @"Quit anyway", @"Cancel", nil);
if (alertReturn == NSAlertAlternateReturn) {
reply = NSTerminateCancel;
}
}
}
}
else {
reply = NSTerminateCancel;
}
}
return reply;
}
/**
Implementation of dealloc, to release the retained variables.
*/
- (void) dealloc {
[managedObjectContext release], managedObjectContext = nil;
[persistentStoreCoordinator release], persistentStoreCoordinator = nil;
[managedObjectModel release], managedObjectModel = nil;
[super dealloc];
}
@end
3 个解决方案
#1
You need to change the if statement to read the boolean value backing the checkbox for the given row from your model. Since you didn't include any information about your model, no-one is going to be able to give you an actual line of code to use.
您需要更改if语句以读取支持模型中给定行的复选框的布尔值。由于您没有包含有关模型的任何信息,因此没有人能够为您提供实际的代码行。
It's also not clear that the rest of the code will do what you want; it's changing the color of the text conditionally, not the row itself.
还不清楚其余的代码是否能达到你想要的效果;它有条件地改变文本的颜色,而不是行本身。
#2
Generally, you do not want to base the display of one cell on the value of another one. A more MVC-compliant approach is to have the checkbox control a property of that row's object (say, isActive), which you can then check against in your code above to decide how to draw the text. As long as the checkbox state and the text color are both based on the same property, they'll match up as you want.
通常,您不希望将一个单元格的显示基于另一个单元格的值。更符合MVC的方法是让复选框控制该行的对象(例如,isActive)的属性,然后您可以在上面的代码中检查该属性以决定如何绘制文本。只要复选框状态和文本颜色都基于相同的属性,它们就会根据需要匹配。
Also, the color you want is not [NSColor lightGrayColor], but rather [NSColor disabledControlTextColor]. And usually, you just want to disable the whole cell, i.e [aCell setEnabled:NO] instead of just changing the text color, which makes it act like a disabled cell as well as look like one.
此外,您想要的颜色不是[NSColor lightGrayColor],而是[NSColor disabledControlTextColor]。通常,您只想禁用整个单元格,即[aCell setEnabled:NO],而不是仅仅更改文本颜色,这使它像一个禁用的单元格一样,看起来像一个。
#3
What does [self visibilityForFile:] return? If it is not a BOOL, then you need to change it to something that does return a BOOL. Why don't you ask your friend what you're supposed to change the line to?
什么[self visibilityForFile:]返回?如果它不是BOOL,那么您需要将其更改为返回BOOL的内容。你为什么不问你的朋友你应该改变什么线?
#1
You need to change the if statement to read the boolean value backing the checkbox for the given row from your model. Since you didn't include any information about your model, no-one is going to be able to give you an actual line of code to use.
您需要更改if语句以读取支持模型中给定行的复选框的布尔值。由于您没有包含有关模型的任何信息,因此没有人能够为您提供实际的代码行。
It's also not clear that the rest of the code will do what you want; it's changing the color of the text conditionally, not the row itself.
还不清楚其余的代码是否能达到你想要的效果;它有条件地改变文本的颜色,而不是行本身。
#2
Generally, you do not want to base the display of one cell on the value of another one. A more MVC-compliant approach is to have the checkbox control a property of that row's object (say, isActive), which you can then check against in your code above to decide how to draw the text. As long as the checkbox state and the text color are both based on the same property, they'll match up as you want.
通常,您不希望将一个单元格的显示基于另一个单元格的值。更符合MVC的方法是让复选框控制该行的对象(例如,isActive)的属性,然后您可以在上面的代码中检查该属性以决定如何绘制文本。只要复选框状态和文本颜色都基于相同的属性,它们就会根据需要匹配。
Also, the color you want is not [NSColor lightGrayColor], but rather [NSColor disabledControlTextColor]. And usually, you just want to disable the whole cell, i.e [aCell setEnabled:NO] instead of just changing the text color, which makes it act like a disabled cell as well as look like one.
此外,您想要的颜色不是[NSColor lightGrayColor],而是[NSColor disabledControlTextColor]。通常,您只想禁用整个单元格,即[aCell setEnabled:NO],而不是仅仅更改文本颜色,这使它像一个禁用的单元格一样,看起来像一个。
#3
What does [self visibilityForFile:] return? If it is not a BOOL, then you need to change it to something that does return a BOOL. Why don't you ask your friend what you're supposed to change the line to?
什么[self visibilityForFile:]返回?如果它不是BOOL,那么您需要将其更改为返回BOOL的内容。你为什么不问你的朋友你应该改变什么线?