ios 打全局的Log日志

具体做法：

 // 将NSlog打印信息保存到Document目录下的文件中

- (void)redirectNSlogToDocumentFolder
{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentDirectory = [paths objectAtIndex:0];
    NSString *fileName = [NSString stringWithFormat:@"dr.log"];// 注意不是NSData!
    NSString *logFilePath = [documentDirectory stringByAppendingPathComponent:fileName];
    // 先删除已经存在的文件
    NSFileManager *defaultManager = [NSFileManager defaultManager];
    [defaultManager removeItemAtPath:logFilePath error:nil];
    
    // 将log输入到文件
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stdout);
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding], "a+", stderr);
} 

在appdelegate.m中应用：

#if !TARGET_IPHONE_SIMULATOR
- (void)redirectNSLogToDocumentFolder{
    NSArray *paths = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory,NSUserDomainMask, YES);
    NSString *documentsDirectory = [paths objectAtIndex:0];
    NSString *fileName =[NSString stringWithFormat:@"%@.log",[NSDate date]];
    NSString *logFilePath = [documentsDirectory stringByAppendingPathComponent:fileName];
    freopen([logFilePath cStringUsingEncoding:NSASCIIStringEncoding],"a+",stderr);
}
#endif
void UncaughtExceptionHandler(NSException *exception) {
    NSArray *arr = [exception callStackSymbols];//得到当前调用栈信息
    NSString *reason = [exception reason];//非常重要，就是崩溃的原因
    NSString *name = [exception name];//异常类型
    NSString *crashLogInfo = [NSString stringWithFormat:@"exception type : %@ \n crash reason : %@ \n call stack info
: %@", name, reason, arr];
    NSString *urlStr = [NSString stringWithFormat:@"mailto://1101023516@qq.com?subject=bug报告&body=感谢您的配合!"
                        "错误详情:%@",crashLogInfo];
    NSURL *url = [NSURL URLWithString:[urlStr stringByAddingPercentEscapesUsingEncoding:NSUTF8StringEncoding]];
    [[UIApplication sharedApplication] openURL:url];
    NSLog(@"crash : %@ \n",crashLogInfo);
}
在- (BOOL)application:(UIApplication
*)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
中：
// objective-c捕获异常
    NSSetUncaughtExceptionHandler(&UncaughtExceptionHandler);