解决方法
看看几个Paint方法：
getTextBounds()和
measureText.我们可以使用它们来确定TextView中文本的偏移量.确定TextView中的偏移后,我们可以将其添加到TextView本身的位置,以确定文本的屏幕坐标(如果需要).
我还发现文章“Android 101: Typography”有助于理解排版的一些复杂性.
以下示例在三个TextView中查找文本的边界,并在文本周围绘制一个矩形.矩形包含TextView中文本的(x,y)坐标.
activity_main.xml中
一个简单的演示布局.
<android.support.constraint.ConstraintLayout
android:id="@+id/layout"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<TextView
android:id="@+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:background="@android:color/holo_blue_light"
android:padding="24dp"
android:text="Hello World"
android:textColor="@android:color/black"
android:textSize="50sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<TextView
android:id="@+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:background="@android:color/holo_blue_light"
android:padding="24dp"
android:text="Hello Worldly"
android:textColor="@android:color/black"
android:textSize="50sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/textView1" />
<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="24dp"
android:background="@android:color/holo_blue_light"
android:padding="24dp"
android:text="aaaaaaaaaa"
android:textColor="@android:color/black"
android:textSize="50sp"
app:layout_constraintLeft_toLeftOf="parent"
app:layout_constraintRight_toRightOf="parent"
app:layout_constraintTop_toBottomOf="@id/textView2" />
</android.support.constraint.ConstraintLayout>
MainActivity.java
public class MainActivity extends AppCompatActivity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
drawTextBounds((TextView) findViewById(R.id.textView1));
drawTextBounds((TextView) findViewById(R.id.textView2));
drawTextBounds((TextView) findViewById(R.id.textView3));
}
private void drawTextBounds(TextView textView) {
// Force measure of text pre-layout.
textView.measure(0,0);
String s = (String) textView.getText();
// bounds will store the rectangle that will circumscribe the text.
Rect bounds = new Rect();
Paint textPaint = textView.getPaint();
// Get the bounds for the text. Top and bottom are measured from the baseline. Left
// and right are measured from 0.
textPaint.getTextBounds(s,s.length(),bounds);
int baseline = textView.getBaseline();
bounds.top = baseline + bounds.top;
bounds.bottom = baseline + bounds.bottom;
int startPadding = textView.getPaddingStart();
bounds.left += startPadding;
// textPaint.getTextBounds() has already computed a value for the width of the text,// however,Paint#measureText() gives a more accurate value.
bounds.right = (int) textPaint.measureText(s,s.length()) + startPadding;
// At this point,(x,y) of the text within the TextView is (bounds.left,bounds.top)
// Draw the bounding rectangle.
Bitmap bitmap = Bitmap.createBitmap(textView.getMeasuredWidth(),textView.getMeasuredHeight(),Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(bitmap);
Paint rectPaint = new Paint();
rectPaint.setColor(Color.RED);
rectPaint.setStyle(Paint.Style.STROKE);
rectPaint.setStrokeWidth(1);
canvas.drawRect(bounds,rectPaint);
textView.setForeground(new BitmapDrawable(getResources(),bitmap));
}
}
