Android Add margins programmatically to Webview

问题

I need to add margins to a webview programmatically. I would like to do something like below:

public void setSideMargin(final int sideMargin, int id) {
    WebView webView = (WebView) ((Activity) context)
            .findViewById(id);

    WebView.LayoutParams p = new WebView.LayoutParams(
            WebView.LayoutParams.MATCH_PARENT,
            WebView.LayoutParams.WRAP_CONTENT);

    p.leftMargin = sideMargin;
    p.rightMargin = sideMargin;

    webView.setLayoutParams(p);
}

This is obviously wrong I know but is there anything like this that I can do to add the margins programmatically? Thanks

回答1:

The thing to understand with LayoutParams is this: The LayoutParams does not depend on the element it is set to, but on the parent.

It is an indication given to the parent regarding the positioning of the element.

Therefore, if your WebView is in a LinearLayout, getLayoutParams will get you a LinearLayout.LayoutParams.

Which means that, in order to have a descendant of MarginLayoutParam, a LayoutParams that supports margins, your WebView must be placed in a ViewGroup that supports margins, such as LinearLayout or RelativeLayout. (see the list of descendants http://developer.android.com/reference/android/view/ViewGroup.MarginLayoutParams.html ). In other words, WebView itself does not support margins, its parent does.

In which case, you should cast the LayoutParams from the WebView to:

ViewGroup.MarginLayoutParams p = (ViewGroup.MarginLayoutParams) webView.getLayoutParams();

Once you have that, you can modify the margins :

p.leftMargin = sideMargin;
p.rightMargin = sideMargin;

webView.setLayoutParams(p);

回答2:

Try with this code:

WebView.LayoutParams layoutParams = (WebView.LayoutParams) webView.getLayoutParams();
webView.layoutParams.leftMargin = sideMargin;
webView.layoutParams.rightMargin = sideMargin;
webView.setLayoutParams(layoutParams);

If doesn't work , then take linearlayout parent of this view and insert padding for it.

Example code:

LinearLayout.LayoutParams layoutParams = (LinearLayout.LayoutParams) webView.getParent().getLayoutParams();
layoutParams.setMargins(sideMargin, 0, sideMargin, 0);
((LinearLayout)webView.getParent()).setLayoutParams(layoutParams);

2th Example code:

LinearLayout webviewLayout = (LinearLayout) webView.getParent();
webviewLayout.setPadding(sideMargin,0,sideMargin,0);

来源：https://stackoverflow.com/questions/23519946/android-add-margins-programmatically-to-webview

标签

java

android

webview

margins