@try - Objective-C 中的 catch 块

发布于 2024-09-11 19:44:57 字数 269 浏览 24 评论 0原文

为什么@try块不起作用？它使应用程序崩溃，但它应该被 @try 块捕获。

 NSString* test = [NSString stringWithString:@"ss"];

 @try {
    [test characterAtIndex:6];

 }
 @catch (NSException * e) {
    NSLog(@"Exception: %@", e);
 }
 @finally {
    NSLog(@"finally");
 }

原文

Why doesn't @try block work?
It crashed the app, but it was supposed to be caught by the @try block.

 NSString* test = [NSString stringWithString:@"ss"];

 @try {
    [test characterAtIndex:6];

 }
 @catch (NSException * e) {
    NSLog(@"Exception: %@", e);
 }
 @finally {
    NSLog(@"finally");
 }

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兔姬 2024-09-18 19:44:57

一切工作都很完美:)

 NSString *test = @"test";
 unichar a;
 int index = 5;
    
 @try {
    a = [test characterAtIndex:index];
 }
 @catch (NSException *exception) {
    NSLog(@"%@", exception.reason);
    NSLog(@"Char at index %d cannot be found", index);
    NSLog(@"Max index is: %lu", [test length] - 1);
 }
 @finally {
    NSLog(@"Finally condition");
 }

日志：

[__NSCFConstantString characterAtIndex:]：范围或索引超出范围
找不到索引 5 处的字符
最大索引为：3
最终条件

All work perfectly :)

 NSString *test = @"test";
 unichar a;
 int index = 5;
    
 @try {
    a = [test characterAtIndex:index];
 }
 @catch (NSException *exception) {
    NSLog(@"%@", exception.reason);
    NSLog(@"Char at index %d cannot be found", index);
    NSLog(@"Max index is: %lu", [test length] - 1);
 }
 @finally {
    NSLog(@"Finally condition");
 }

Log: