小编ken*_*ger的帖子

我正在尝试让这个函数工作,这对请求参数url然后发送callback一个函数的responseText .

它似乎只能到达readyState 1(感谢Firebug命令).

这里是:

function Request(url, callback){
if (window.XMLHttpRequest) { // Mozilla, Safari, ...
    httpRequest = new XMLHttpRequest();
} else if (window.ActiveXObject) { // IE
    httpRequest = new ActiveXObject("Microsoft.XMLHTTP");
} else{
    return false;
}
httpRequest.onreadystatechange = function(){
    console.log(httpRequest.readyState);
    if (httpRequest.readyState == 4) {
        callback(httpRequest.responseText);
    }
};
console.log(httpRequest, url);
httpRequest.open('GET', url, true);
httpRequest.send(null);
}

我正在尝试使用Outline视图来显示目录,现在我已经编辑了Apple的示例,使其可以在我设置的任何目录中工作,除非在扩展任何节点时我从NSOutlineView类获得"EXEC_BAD_ACCESS".

这是头文件:

#import <Cocoa/Cocoa.h>

@interface SMLDirectoryDataSource : NSObject {
    NSString *rootDirectory;
}

- (int)outlineView:(NSOutlineView *)outlineView numberOfChildrenOfItem:(id)item;
- (BOOL)outlineView:(NSOutlineView *)outlineView isItemExpandable:(id)item;
- (id)outlineView:(NSOutlineView *)outlineView
            child:(int)index
           ofItem:(id)item;
- (id)outlineView:(NSOutlineView *)outlineView objectValueForTableColumn:(NSTableColumn *)tableColumn
           byItem:(id)item;
- (void) setRootDirectory:(NSString *)directory;

@end

@interface SMLDirectoryDataItem : NSObject
{
    NSString *relativePath, *fullPath;
    SMLDirectoryDataItem *parent;
    NSMutableArray *children;
}

//+ (SMLDirectoryDataItem *)rootItem;
- (int)numberOfChildren;// Returns -1 for leaf nodes
- (SMLDirectoryDataItem *)childAtIndex:(int)n;// Invalid to call on leaf nodes
- (NSString *)fullPath;
- (NSString *)relativePath;

@end

这是实现文件:

#import "SMLDirectoryDataSource.h"


@implementation SMLDirectoryDataSource …