异常 Unhandled Exception: FormatException: Unexpected character (at character 2) 分析 flutter json报以上错误,我这里是请求登录的接口
= -1) { throw new FormatException("不支持指定多个“第N”天。" = '\t') { throw new FormatException("'?' = DayOfWeek) { throw new FormatException($"'#' 选项在这里无效。 = AllSpecInt) { throw new FormatException("小时值必须介于0和23之间" = NoSpecInt) { throw new FormatException("月日值必须介于1和31之间")
If str is not an integer value, it will throw FormatException. 遇到null引用时,抛出ArgumentNullException;如果字符串不是整数值,抛出FormatException;当字符串代表数字小于MinValue(−2,147,483,648) 或大于 If str is other than integer value, it will throw FormatException. 如果str不是整数值,抛出FormatException。 如果参数不是整数,out 变量将是0,而不是抛出FormatException 。
(args.Length > 0) { throw new NotSupportedException( Resources.FormatException middleware factory throw new InvalidOperationException( Resources.FormatException IsAssignableFrom(methodInfo.ReturnType)) { throw new InvalidOperationException( Resources.FormatException = typeof(HttpContext)) { throw new InvalidOperationException( Resources.FormatException\_ (serviceProvider == null) { throw new InvalidOperationException( Resources.FormatException
(args.Length > 0) { throw new NotSupportedException( Resources.FormatException_UseMiddlewareExplicitArgumentsNotSupported middleware factory throw new InvalidOperationException( Resources.FormatException_UseMiddlewareNoMiddlewareFactory ToArray(); if (invokeMethods.Length > 1) { throw new InvalidOperationException( Resources.FormatException_UseMiddleMutlipleInvokes IsAssignableFrom(methodInfo.ReturnType)) { throw new InvalidOperationException( Resources.FormatException_UseMiddlewareNonTaskReturnType = typeof(HttpContext)) { throw new InvalidOperationException( Resources.FormatException_UseMiddlewareNoParameters
如果发生异常,可以使用 on 或 catch 来捕获并处理它 finally 块中的代码无论是否发生异常都会执行 void main() { try { // 尝试执行的代码 throw FormatException ; } on FormatException catch (e) { // 捕获特定类型的异常 print('捕获到格式异常: ${e.message}'); } catch (
如果发生异常,可以使用 on 或 catch 来捕获并处理它 finally 块中的代码无论是否发生异常都会执行 void main() { try { // 尝试执行的代码 throw FormatException ; } on FormatException catch (e) { // 捕获特定类型的异常 print('捕获到格式异常: ${e.message}'); } catch (
e.getMessage() + "\n"); Log.e("myonclick", "读取nfc异常", e); } catch (FormatException e.getMessage() + "\n"); Log.e("myonclick", "写nfc异常", e); } catch (FormatException e.getMessage() + "\n"); Log.e("myonclick", "删除nfc异常", e); } catch (FormatException promt.setText(metaInfo); } // 读取方法 private String read(Tag tag) throws IOException, FormatException } return null; } // 写入方法 private void write(Tag tag) throws IOException, FormatException
但当我们输入的不是整数时,就出现了异常: System.FormatException: Input string was not in a correct format. { Console.WriteLine("程序执行完毕"); } } } } 当错误输入时的输出: System.FormatException
1.42) Output(PassedInt -12400) c Currency {0:c} $1.42 -$12,400 d Decimal (Whole number) {0:d} System.FormatException 1.42 -12400 n Number with commas for thousands {0:n} 1.42 -12,400 r Round trippable {0:r} 1.42 System.FormatException x Hexadecimal {0:x4} System.FormatException cf90 Specifier Type Example (Passed System.DateTime.Now
FormatException -12400 e Scientific {0:e} 1.420000e+000 -1.240000e+004 f Fixed point {0:f} 1.42 -12400.00 FormatException x Hexadecimal {0:x4} System. FormatException cf90 Specifier Type Example (Passed System.DateTime.Now) d Short date 10/12/2002 D Long
如果字符串为空,则抛出ArgumentNullException异常; 如果字符串内容不是数字,则抛出FormatException异常; 如果字符串内容所表示数字超出int类型可表示的范围,则抛出
(() { return this.barcode = 'Unknown error: $e'; }); } } on FormatException return this.barcode = 'Unknown error: $e'; }); } } on FormatException
dart中也有很多Exception的子类,比如FormatException来表示各种不同的异常情形。 比如我们throw一个格式异常: throw FormatException('这是一个格式异常'); 但是在dart中,不仅仅可以throw Exception或者Error,任何一个Object都可以
// Uri parsing may fail, so we use a try/catch FormatException. uri and warn the user, if it is not correct, // but keep in mind it could be `null`. } on FormatException
例如: // 高成本:无效输入时抛出异常 try { intvalue = int.Parse("invalid"); } catch (FormatException ex) 性能分析显示12%的请求因格式错误触发FormatException,单次异常消耗约2ms,每千次请求累计浪费2.4秒CPU时间。
} else { throw new FormatException Result = double.Parse(Value, NumberStyles.Any, info2); flag1 = true; } catch (FormatException
---- 5.异常处理 5.1:异常不处理的情况 结果由于FormatException异常,程序直接崩溃 这并不是我们想要的,直接崩溃会造成极差的用户体验。 void main() { print(str2Num("a"));//FormatException: a } num str2Num(String str){ return num.parse num str2Num(String str){ var result= 0; try { result= num.parse(str); } on FormatException
如果字符串为空,则抛出ArgumentNullException异常; 如果字符串内容不是数字,则抛出FormatException异常; 如果字符串内容所表示数字超出int类型可表示的范围,则抛出
_scanResultStr = 'Unknown error: $e'; }); } } on FormatException { setState((