使用变量 img 是多余的吗？

Question

首先我必须说代码运行完美。

但我担心使用这种方式 img 变量是多余的，因为我还有变量 _originalImage。

类顶部的代码：

    private bool _DisplayFocusCues = true;
    private Image _originalImage;
    private Image _clickImage;
    private Image img;

    public CustomButton()
    {
        this.FlatStyle = FlatStyle.Flat;
        this.FlatAppearance.BorderSize = 0;
        this.FlatAppearance.BorderColor = Color.FromArgb(0, 255, 255, 255); // Transparent
        this.FlatAppearance.MouseDownBackColor = Color.FromArgb(0, 255, 255, 255); // Transparent on click
        this.FlatAppearance.MouseOverBackColor = Color.FromArgb(0, 255, 255, 255); // Transparent on hover
        this.DisplayFocusCues = false;

        // Assume Properties.Resources.YourImageResource is the resource identifier for your image
        img = ResizeImage(Properties.Resources.icons8_record_32, 50, 50);
        this.Image = img;
        this.Size = img.Size;
        _originalImage = img;
    }

然后在 OnMouseUp 事件中

protected override void OnMouseUp(MouseEventArgs mevent)
{
    base.OnMouseUp(mevent);
    _originalImage = img;
    this.Image = _originalImage;
}

我使用 img 变量的原因是因为在 OnMouseUp 事件中以这种方式使用它时，它会产生单击按钮更改颜色的按钮单击效果。

如果没有 img 变量，当我每次单击按钮时，它都会使按钮颜色越来越暗，并且永远不会返回到按钮原始颜色。

Answer 1

我还没有测试以下代码，但我认为这会起作用。

private bool _DisplayFocusCues = true;
private Image _originalImage;
private Image _clickImage;

public CustomButton()
{
    this.FlatStyle = FlatStyle.Flat;
    this.FlatAppearance.BorderSize = 0;
    this.FlatAppearance.BorderColor = Color.FromArgb(0, 255, 255, 255); // Transparent
    this.FlatAppearance.MouseDownBackColor = Color.FromArgb(0, 255, 255, 255); // Transparent on click
    this.FlatAppearance.MouseOverBackColor = Color.FromArgb(0, 255, 255, 255); // Transparent on hover
    this.DisplayFocusCues = false;

    // Assume Properties.Resources.YourImageResource is the resource identifier for your image
    this.Image = ResizeImage(Properties.Resources.icons8_record_32, 50, 50);
    this.Size = this.Image.Size;
    _originalImage = this.Image;
}

protected override void OnMouseUp(MouseEventArgs mevent)
{
    base.OnMouseUp(mevent);
    this.Image = _originalImage;
}

protected override void OnMouseDown(MouseEventArgs mevent)
{
    base.OnMouseDown(mevent);
    if (_clickImage != null)
        this.Image = _clickImage;
}