如何在Xamarin.IoS中执行StringFormat

Question

how to change the following C objective code to c# Xamarin.IoS

NSString label;
NSString string = 50.ToString("%0.0f");
string = [label stringByAppendingString:string];
string = [string stringByAppendingString:label];

Answer 1

Here are some examples of regular string formatting in C#:

var formattedString = string.Format("This first variable {0} and second variable {1}", firstVar, secondVar);
var formattedString = $"This first variable {firstVar} and second variable {secondVar}";

for formatting numbers in strings, check out these docs: https://msdn.microsoft.com/en-us/library/8wch342y(v=vs.110).aspx .

int value = -16325;
string specifier;

// Use standard numeric format specifier.
specifier = "G";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    G: -16325
specifier = "C";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    C: ($16,325.00)
specifier = "D8";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    D8: -00016325
specifier = "E4";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    E4: -1.6325E+004
specifier = "e3";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    e3: -1.633e+004
specifier = "F";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    F: -16325.00
specifier = "N";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    N: -16,325.00
specifier = "P";
Console.WriteLine("{0}: {1}", specifier, (value/100000).ToString(specifier));
// Displays:    P: -16.33 %
specifier = "X";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    X: FFFFC03B 

// Use custom numeric format specifiers.
specifier = "0,0.000";
Console.WriteLine("{0}: {1}", specifier, value.ToString(specifier));
// Displays:    0,0.000: -16,325.000
specifier = "#,#.00#;(#,#.00#)";
Console.WriteLine("{0}: {1}", specifier, (value*-1).ToString(specifier));
// Displays:    #,#.00#;(#,#.00#): 16,325.00

You can use a combination of these like this:

var finalString = 50.ToString("0.0");
finalString += label;