简单的Kotlin扩展方案

单独设置所有/任何边:

fun View.setMargin(left: Int? = null, top: Int? = null, right: Int? = null, bottom: Int? = null) {
    val params = (layoutParams as? MarginLayoutParams)
    params?.setMargins(
            left ?: params.leftMargin,
            top ?: params.topMargin,
            right ?: params.rightMargin,
            bottom ?: params.bottomMargin)
    layoutParams = params
}

myView.setMargin(10, 5, 10, 5)
// or just any subset
myView.setMargin(right = 10, bottom = 5)

直接引用资源值:

fun View.setMarginRes(@DimenRes left: Int? = null, @DimenRes top: Int? = null, @DimenRes right: Int? = null, @DimenRes bottom: Int? = null) {
    setMargin(
            if (left == null) null else resources.getDimensionPixelSize(left),
            if (top == null) null else resources.getDimensionPixelSize(top),
            if (right == null) null else resources.getDimensionPixelSize(right),
            if (bottom == null) null else resources.getDimensionPixelSize(bottom),
    )
}

myView.setMarginRes(top = R.dimen.my_margin_res)

直接将所有方面平等地设置为属性:

var View.margin: Int
    get() = throw UnsupportedOperationException("No getter for property")
    set(@Px margin) = setMargin(margin, margin, margin, margin)
   
myView.margin = 10 // px

// or as res
var View.marginRes: Int
    get() = throw UnsupportedOperationException("No getter for property")
    set(@DimenRes marginRes) {
        margin = resources.getDimensionPixelSize(marginRes)
    }

myView.marginRes = R.dimen.my_margin_res

为了直接设置一个特定的边，你可以像这样创建一个属性扩展:

var View.leftMargin
    get() = marginLeft
    set(@Px leftMargin) = setMargin(left = leftMargin)

var View.leftMarginRes: Int
    get() = throw UnsupportedOperationException("No getter for property")
    set(@DimenRes leftMarginRes) {
        leftMargin = resources.getDimensionPixelSize(leftMarginRes)
    }

这也允许你做出水平或垂直的变化:

var View.horizontalMargin
    get() = throw UnsupportedOperationException("No getter for property")
    set(@Px horizontalMargin) = setMargin(left = horizontalMargin, right = horizontalMargin)

var View.horizontalMarginRes: Int
    get() = throw UnsupportedOperationException("No getter for property")
    set(@DimenRes horizontalMarginRes) {
        horizontalMargin = resources.getDimensionPixelSize(horizontalMarginRes)
    }

注意:如果margin设置失败，你可能在渲染之前太早了，这意味着params == null。尝试用myView包装修改。Post {margin = 10}

((FrameLayout.LayoutParams) linearLayout.getLayoutParams()).setMargins(450, 20, 0, 250);
        linearLayout.setBackgroundResource(R.drawable.smartlight_background);

我不得不将我的linearLayout转换为FrameLayout，因为它继承了linearLayout，并在那里设置了边缘，这样活动就只出现在屏幕的一部分，与setContentView中的原始布局参数不同。

LinearLayout linearLayout = (LinearLayout) findViewById(R.id.activity);
LinearLayout.LayoutParams layoutParams = new LinearLayout.LayoutParams(WindowManager.LayoutParams.FILL_PARENT, WindowManager.LayoutParams.MATCH_PARENT);
linearLayout.setBackgroundColor(getResources().getColor(R.color.full_white));
setContentView(linearLayout,layoutParams);

其他人都不能使用相同的活动，并根据从不同菜单打开活动来更改边距!setLayoutParams从来不为我工作-设备每次都会崩溃。尽管这些都是硬编码的数字，但这只是用于演示目的的代码示例。

Layout_margin是子视图告诉父视图的约束。然而，是否允许保证金是由母公司决定的。基本上通过设置android:layout_margin="10dp"，子视图请求父视图组分配比其实际大小大10dp的空间。(另一方面，padding="10dp"意味着子视图将自己的内容缩小10dp。)

因此，并非所有viewgroup都尊重边缘。最臭名昭著的例子是listview，其中项的边距被忽略。在你调用setMargin()到一个LayoutParam之前，你应该始终确保当前视图位于一个支持margin的ViewGroup中(例如LinearLayouot或RelativeLayout)，并将getLayoutParams()的结果转换为你想要的特定的LayoutParams。(ViewGroup。LayoutParams甚至没有setedges()方法!)

下面的函数应该可以做到这一点。但是，请确保将RelativeLayout替换为父视图的类型。

private void setMargin(int marginInPx) {
    RelativeLayout.LayoutParams lp = (RelativeLayout.LayoutParams) getLayoutParams();
    lp.setMargins(marginInPx,marginInPx, marginInPx, marginInPx);
    setLayoutParams(lp);
}

感兴趣的人可以使用DP工作utils函数:

public static void setMargins(Context context, View view, int left, int top, int right, int bottom) {
    int marginLeft = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, left, context.getResources().getDisplayMetrics());
    int marginTop = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, top, context.getResources().getDisplayMetrics());
    int marginRight = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, right, context.getResources().getDisplayMetrics());
    int marginBottom = (int) TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, bottom, context.getResources().getDisplayMetrics());

    if (view.getLayoutParams() instanceof ViewGroup.MarginLayoutParams) {
        ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) view.getLayoutParams();
        p.setMargins(marginLeft, marginTop, marginRight, marginBottom);
        view.requestLayout();
    }
}

LayoutParams - NOT WORKING !！ ！

需要使用类型:MarginLayoutParams

MarginLayoutParams params = (MarginLayoutParams) vector8.getLayoutParams();
params.width = 200; params.leftMargin = 100; params.topMargin = 200;

MarginLayoutParams的代码示例:

http://www.codota.com/android/classes/android.view.ViewGroup.MarginLayoutParams

我在kotlin就是这样做的

fun View.setTopMargin(@DimenRes dimensionResId: Int) {
    (layoutParams as ViewGroup.MarginLayoutParams).topMargin = resources.getDimension(dimensionResId).toInt()
}