How to resize a custom view programmatically?

问题

I am coding a custom view, extended from RelativeLayout, and I want to resize it programmatically, How can I do?

the custom view Class is something like:

public ActiveSlideView(Context context, AttributeSet attr){
        super(context, attr);
        LayoutInflater inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        if(inflater != null){       
            inflater.inflate(R.layout.active_slide, this);
        }

回答1:

Android throws an exception if you fail to pass the height or width of a view. Instead of creating a new LayoutParams object, use the original one, so that all other set parameters are kept. Note that the type of LayoutParams returned by getLayoutParams is that of the parent layout, not the view you are resizing.

RelativeLayout.LayoutParams params = (RelativeLayout.LayoutParams) someLayout.getLayoutParams();
params.height = 130;
someLayout.setLayoutParams(params);

回答2:

this.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.FILL_PARENT, theSizeIWant));

Problem solved!

NOTE: Be sure to use the parent Layout's LayoutParams. Mine is LinearLayout.LayoutParams!

回答3:

This works for me:

ViewGroup.LayoutParams params = layout.getLayoutParams();
params.height = customHeight;
layout.requestLayout();

回答4:

For what it's worth, let's say you wanted to resize the view in device independent pixels (dp): -

You need to use a method called applyDimension, that's a member of the class TypedValue to convert from pixels to dps. So if I want to set the height to 150dp (say) - then I could do this:

float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 150, getResources().getDisplayMetrics());
LinearLayout.LayoutParams params = (LinearLayout.LayoutParams) someLayout.getLayoutParams();
params.height = (int) pixels;
someLayout.setLayoutParams(params);

where the expression: getResources().getDisplayMetrics() gets the screen density/resolution

回答5:

In Kotlin, you can use the ktx extensions:

yourView.updateLayoutParams {
   height = <YOUR_HEIGHT>
}

回答6:

Here's a more generic version of the solution above from @herbertD :

private void resizeView(View view, int newWidth, int newHeight) { 
    try { 
        Constructor<? extends LayoutParams> ctor = view.getLayoutParams().getClass().getDeclaredConstructor(int.class, int.class); 
        view.setLayoutParams(ctor.newInstance(newWidth, newHeight));   
    } catch (Exception e) { 
        e.printStackTrace(); 
    }
}

回答7:

try a this one:

...
View view = inflater.inflate(R.layout.active_slide, this);
view.setMinimumWidth(200);

回答8:

I used this way to increase width of custom view

customDrawingView.post(new Runnable() {
                            @Override
                            public void run() {
                                View view_instance = customDrawingView;
                                android.view.ViewGroup.LayoutParams params = view_instance
                                        .getLayoutParams();
                                int newLayoutWidth = customDrawingView
                                        .getWidth()
                                        + customDrawingView.getWidth();
                                params.width = newLayoutWidth;
                                view_instance.setLayoutParams(params);
                                screenWidthBackup = params.width;
                            }
                        });

回答9:

I solved it this way.. I have basically a simple view inside xml file.

 View viewname = findViewById(R.id.prod_extra);
             prodExtra.getLayoutParams().height=64;

回答10:

If you have only two or three condition(sizes) then you can use @Overide onMeasure like

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) 
{
    super.onMeasure(widthMeasureSpec, heightMeasureSpec);
}

And change your size for these conditions in CustomView class easily.

回答11:

if you are overriding onMeasure, don't forget to update the new sizes

@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
    setMeasuredDimension(newWidth, newHeight);
}

回答12:

This is how I achieved this. In Sileria answer he/she did the following:

ViewGroup.LayoutParams params = layout.getLayoutParams();
params.height = customHeight;
layout.requestLayout();

This is correct, but it expects us to give the height in pixels, but I wanted to give the dp I want the height to be so I added:

public int convertDpToPixelInt(float dp, Context context) {
    return (int) (dp * (((float) context.getResources().getDisplayMetrics().densityDpi) / 160.0f));
}

So it will look like this:

ViewGroup.LayoutParams params = layout.getLayoutParams();
params.height = convertDpToPixelInt(50, getContext());
layout.requestLayout();

来源：https://stackoverflow.com/questions/2963152/how-to-resize-a-custom-view-programmatically

标签

android

resize