如何制作自定义textView？

Question

My TextViews xml file

<com.example.blabla.HateTextView
xmlns:android="http://schemas.android.com/apk/res/android"
android:id="@+id/hate"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Text" />

Next code

public class HateTextView extends android.support.v7.widget.AppCompatTextView {

    Paint mTxtPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
    private String str = " ";

    HateTextView(Context context, AttributeSet attrs){
        super(context, attrs);
        TypedArray a = getContext().obtainStyledAttributes(attrs, R.styleable.HateTextView);
        a.recycle();
    }

    @Override
    public void onDraw(Canvas canvas) {
        super.onDraw(canvas);
        Paint.FontMetrics fm = new Paint.FontMetrics();
        mTxtPaint.setColor(Color.parseColor("#d00000"));
        mTxtPaint.setTextSize(20 * getResources().getDisplayMetrics().density);
        mTxtPaint.getFontMetrics(fm);
        mTxtPaint.isAntiAlias();

        int margin = 5;

        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
            canvas.drawRoundRect(90 - margin, 100 + fm.top - margin,
                    115 + mTxtPaint.measureText(str) + margin, 100 + fm.bottom + margin,35,35, mTxtPaint);
        }

        mTxtPaint.setColor(Color.WHITE);
        canvas.drawText(str, 100, 100, mTxtPaint);
    }

    public void setTextHate(String hate) {
        str = hate;
    }
}

I create something like this:

HateTextView h = itemView.findViewById(R.id.hate);
h.setTextHate("some text..");
h.setRotation(number);

just because of the rotation so many problems. Or rather because of antialias. Simply from xml getPaint.AntiAlia .. does not work.

the problem looks like this

Here I put "match_parent", and if I put "content" of the text that I'm drawing is not visible at all. How do I insert "Text" into my text instead, which I draw.

Answer 1

 public void setTextHate(String hate) {
    str = hate;
}

after set str = hate, you have to call invalidate(); to call onDraw(Canvas canvas) again.