Question

我有一个验证方法，通过它我可以分析特定变量是否通过了验证标准。

以下是代码：

-(void)scaleTextView:(UIPinchGestureRecognizer *)pinchGestRecognizer{

CGFloat scale = pinchGestRecognizer.scale;
CGFloat lastScale;
lastScale = 1.0;
if([pinchGestRecognizer state] == UIGestureRecognizerStateEnded) {
    // Reset last scale
    lastScale = 1.0;
    return;
}
if ([pinchGestRecognizer state] == UIGestureRecognizerStateBegan ||
    [pinchGestRecognizer state] == UIGestureRecognizerStateChanged) {

    CGFloat pinchscale = [pinchGestRecognizer scale];
    CGFloat scaleDiff = pinchscale - lastScale;

    if (scaleDiff < 0){
        scaleDiff *= 2; // speed up zoom-out 
        [self zoomSymbol:selectObject Scale:-scale];
    }
    else{
        scaleDiff *= 0.7; // slow down zoom-in 
        [self zoomSymbol:selectObject Scale:scale];
        lastScale = pinchscale;
    }
}    
}

我收到警告'存储到'lastScale'的值永远不会被读取'并且'存储到'scaleDiff'的值永远不会被读取' 任何人都能解释一下我的问题在这里。谢谢大家！

Answer 1

lastScale是一个局部变量，永远不会出现在gestureRecognizer的所有状态属性中。您应该使用static变量。

static CGFloat lastScale = 1.0;
...

永远不会读取存储到“lastScale”的值

1 个答案: