[英]AFURLConnectionOperation.m Implicit conversion loses integer precision: 'int64_t' (aka 'long long') to 'NSInteger' (aka 'int')
[英]Implicit conversion loses integer precision: 'long long' to 'NSInteger' (aka 'int')
我試圖將類型為“long long”的變量賦值給NSUInteger類型,這樣做的正確方法是什么?
我的代碼行:
expectedSize = response.expectedContentLength > 0 ? response.expectedContentLength : 0;
其中expectedSize
的類型為NSUInteger,返回類型為response.expectedContentLength
,類型為“ long long
”。 變量response
的類型為NSURLResponse
。
顯示的編譯錯誤是:
語義問題:隱式轉換失去整數精度:'long long'到'NSUInteger'(又名'unsigned int')
你可以嘗試使用NSNumber進行轉換:
NSUInteger expectedSize = 0;
if (response.expectedContentLength) {
expectedSize = [NSNumber numberWithLongLong: response.expectedContentLength].unsignedIntValue;
}
它實際上只是一個演員,有一些范圍檢查:
const long long expectedContentLength = response.expectedContentLength;
NSUInteger expectedSize = 0;
if (NSURLResponseUnknownLength == expectedContentLength) {
assert(0 && "length not known - do something");
return errval;
}
else if (expectedContentLength < 0) {
assert(0 && "too little");
return errval;
}
else if (expectedContentLength > NSUIntegerMax) {
assert(0 && "too much");
return errval;
}
// expectedContentLength can be represented as NSUInteger, so cast it:
expectedSize = (NSUInteger)expectedContentLength;
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