Xamarin.Android中GridLayout的Column Span不生效问题求助

嘿，我瞅了下你的代码，问题出在GridLayout.InvokeSpec的参数顺序上！你现在把起始位置和跨度的参数搞反了，导致列跨度的设置根本没起作用。

问题根源 #

在Xamarin.Android里，GridLayout.InvokeSpec的第一个参数是跨度值，第二个参数才是起始索引。你原来的写法是把起始位置放在前面、跨度放后面，等于告诉GridLayout：“从跨度值的位置开始，占起始索引这么多空间”，这完全和你的需求反过来了！

修正方案 #

我帮你调整了addViewToGridLayout方法的参数顺序，同时优化了按钮的布局参数（用GridLayout专属的LayoutParams代替ViewGroup的，适配性更好）：

protected override void OnCreate(Bundle savedInstanceState) {
    base.OnCreate(savedInstanceState);
    Xamarin.Essentials.Platform.Init(this, savedInstanceState);
    RelativeLayout mainlayout = new RelativeLayout(this);
    RelativeLayout.LayoutParams layoutparameter = new RelativeLayout.LayoutParams(RelativeLayout.LayoutParams.MatchParent, RelativeLayout.LayoutParams.MatchParent);
    mainlayout.LayoutParameters = layoutparameter;
    GridLayout gl = getView();
    mainlayout.AddView(gl);
    SetContentView(mainlayout);
}

private GridLayout getView() {
    GridLayout gridlayout = new GridLayout(this);
    Button b = new Button(this);
    b.Text = "Button1";
    gridlayout.LayoutParameters = new ViewGroup.LayoutParams(ViewGroup.LayoutParams.MatchParent, ViewGroup.LayoutParams.MatchParent);
    gridlayout.RowCount = 2;
    gridlayout.ColumnCount = 2;
    addViewToGridLayout(gridlayout, b, 0, 1, 0, 2);// 此处设置列跨度为2
    return gridlayout;
}

private void addViewToGridLayout(GridLayout pGridLayout, View view, int row, int pRowSpan, int column, int pColumnSpan) {
    // 修正InvokeSpec的参数顺序：先跨度，后起始索引
    Spec rowSpec = GridLayout.InvokeSpec(pRowSpan, row);
    Spec columnSpec = GridLayout.InvokeSpec(pColumnSpan, column);
    GridLayout.LayoutParams gridParam = new GridLayout.LayoutParams(rowSpec, columnSpec);
    // 让按钮填满分配的单元格空间
    gridParam.Width = GridLayout.LayoutParams.MatchParent;
    gridParam.Height = GridLayout.LayoutParams.MatchParent;
    view.LayoutParameters = gridParam;
    pGridLayout.AddView(view);
}

额外说明 #

• 修正后的InvokeSpec调用，会正确告诉GridLayout：按钮从第0行开始占1行，从第0列开始占2列，完美实现跨列效果。
• 给按钮的GridLayout参数设置MatchParent，确保按钮能填满分配给它的单元格空间，不会出现大小适配问题。

内容的提问来源于stack exchange，提问作者jad