CA1830: Prefer strongly-typed Append and Insert method overloads on StringBuilder
| Property | Value |
|---|---|
| Rule ID | CA1830 |
| Title | Prefer strongly-typed Append and Insert method overloads on StringBuilder |
| Category | Performance |
| Fix is breaking or non-breaking | Non-breaking |
| Enabled by default in .NET 9 | As suggestion |
Cause
An StringBuilder Append or Insert method was called with an argument that was the result of calling ToString on a type for which the Append or Insert method has a dedicated overload.
Rule description
Append and Insert provide overloads for multiple types beyond String. When possible, prefer the strongly-typed overloads over using ToString() and the string-based overload.
How to fix violations
Delete the unnecessary ToString() from the invocation.
using System.Text;
class C
{
int _value;
// Violation
public void Log(StringBuilder destination)
{
destination.Append("Value: ").Append(_value.ToString()).AppendLine();
}
// Fixed
public void Log(StringBuilder destination)
{
destination.Append("Value: ").Append(_value).AppendLine();
}
}
When to suppress warnings
It's safe to suppress a violation of this rule if you're not concerned about the performance impact from unnecessary string allocations.
Suppress a warning
If you just want to suppress a single violation, add preprocessor directives to your source file to disable and then re-enable the rule.
#pragma warning disable CA1830
// The code that's violating the rule is on this line.
#pragma warning restore CA1830
To disable the rule for a file, folder, or project, set its severity to none in the configuration file.
[*.{cs,vb}]
dotnet_diagnostic.CA1830.severity = none
For more information, see How to suppress code analysis warnings.
