.NET Best Practices: Business Logic Reduces Usage Exceptions

In .NET development, exception handling is an important means to ensure application robustness, but it should not be abused.

The logic performance of exception raising and catching is poorer than that of ordinary code, soHot path(Frequently executed code path), avoiding relying on exceptions to control program flow is one of the keys to improving performance.

Why reduce the use of exceptions?

Large performance overhead: The exception handling mechanism involves stack backtracking and additional system calls, which may significantly affect performance.

Poor code readability: Frequent use of exceptions to control processes will make the code difficult to maintain.

Increased debugging complexity: Abuse of exceptions will cause real errors to be covered up and increase the difficulty of troubleshooting.

Common error usage and improvement solutions

Avoid using exceptions for existence checks

Error demonstration:usetry-catchTo detect whether the file exists.

try
 {
     var content = ("");
 }
 catch (FileNotFoundException)
 {
     ("file not found.");
 }

Improvement plan: Use condition judgment to replace the exception control process.

if ((""))
 {
     var content = ("");
 }
 else
 {
     ("file not found.");
 }

Avoid dependency exceptions in collection operations

Error demonstration: Use exception handling instead of key existence check.

try
 {
     var value = myDictionary["key"];
 }
 catch (KeyNotFoundException)
 {
     ("The key does not exist.");
 }

Improvement plan:useTryGetValueCheck the existence of the key in advance.

if (("key", out var value))
 {
     ($" Found value: {value}");
 }
 else
 {
     ("The key does not exist.");
 }

Exception handling in input verification

Error demonstration: Try to parse user input directly and catch the exception handling invalid input.

try
 {
     int number = (userInput);
 }
 catch (FormatException)
 {
     ("The input is not a valid number.");
 }

Improvement plan:useTryParsePerform input verification.

if ((userInput, out int number))
 {
     (The number entered by $" is: {number}");
 }
 else
 {
     ("The input is not a valid number.");
 }

When should exception be used?

Although reducing exception usage can help improve performance,Unexpected errororUnavoidable exceptionsWhen , exceptions should still be used to ensure the robustness of the program. For example:

1. Network request failed (such as API is not available)

2. File system permission issues

3. Database connection timeout

try
 {
     var response = await ("/data");
     ();
 }
 catch (HttpRequestException ex)
 {
     ($"Request failed: {}");
 }

How to identify and optimize exceptions?

Use Application Insights or other diagnostic tools
Application Insights can help you monitor and analyze application anomalies and identify bottlenecks that affect performance.

Performance analysis tools
Use Visual Studio's performance analyzer to locate code snippets that frequently throw exceptions.

Logging
Adding detailed logging to critical code paths helps discover hidden exceptions.

Summarize

In .NET development, exceptions should be used as tools to deal with unexpected errors, rather than as a means to control normal program flow. By adding appropriate logic checks to the code, unnecessary exceptions can be effectively reduced, and application performance and code maintainability can be improved.

Best Practice Review：

1. Use conditional statements orTryMethod replaces exception.

2. Use only when handling exceptionstry-catch, such as unpredictable errors.

3. Use diagnostic tools to analyze abnormalities and optimize performance bottlenecks.