如何在程序内将布局和文本大小设置为 DP？

Question

Basically I have this inside XML, but I have to recreate it inside a code. How do I do it?

<EditText 
        android:layout_width="140dp"
        android:layout_height="20dp"
        android:background="@drawable/input_bg01"
        android:textSize="10dp"
        android:gravity="center"
        android:text="111-222-333     FOOO" />

I can use this to set text size, but what about the layout_width and height?

edTxt.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 10);

Is there a way to tell the code to use DP unit instead of pixel? Or a conversion function to convert DP into pixel?

Answer 1

You can use:

float pixels = TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, 10, getResources().getDisplayMetrics());

Now the value of pixels is equivalent to 10dp at the device's current screen density.

The TypedValue contains other similar methods that help in conversion.

Answer 2

Solved here .

Extract:

DisplayMetrics metrics = getContext().getResources().getDisplayMetrics();
float dp = 20f;
float fpixels = metrics.density * dp;
int pixels = (int) (fpixels + 0.5f);

Answer 3

Just for completeness: Another solution (which I'd prefer) for the question is given here

setTextSize(float) expects a scaled pixel value. So, setTextSize(10) would give you the desired result. However, getDimension() and getDimensionPixelSize() return the size in units of pixels.

So for your example it would be

setTextSize(TypedValue.COMPLEX_UNIT_PX, getResources().getDimensionPixelSize(R.dimen.edTxt_text_size));

where <dimen name="edtxt_text_size">10dp</dimen> is set in your dimens.xml file for example.

Answer 4

Regarding setting the TEXT SIZE:

For 2021 ...

Fortunately, the correct modern answer is just

textView.setTextSize(TypedValue.COMPLEX_UNIT_DIP, 25);

or you can use COMPLEX_UNIT_SP, etc.

Exactly matches xml for text size:

Checked, on all devices this produces exactly the same result as just setting it in xml:

---

Regarding setting, say, a layout parameter:

int h = 66; // the new value
ViewGroup.LayoutParams p = some_frame.getLayoutParams();
float fdp = TypedValue.applyDimension(
    TypedValue.COMPLEX_UNIT_DIP,
    h,
    getResources().getDisplayMetrics());
p.height = Math.round(fdp);
some_frame.setLayoutParams(p);

This appears to work correctly, on a test device. The value "h" is now the "same" as simply in the xml, enter 66dp.