Paint.getTextBounds（）返回到大高度 [英] Paint.getTextBounds() returns to big height

问题描述

编辑：这个问题从仿真器来了，错误并没有出现真正的设备上：（

我想画一些文本在自定义视图，必须有没有措施，但在Paint.getTextBounds（）的返回值的高度大约高出30％，那么实际的文本赋予一切古怪的样子。

我发现这个： Android的油漆：.measureText（）VS .getTextBounds（）并试图解决方案code添加到我自己的onDraw，看到我同样的测量误差在我的code。下面是结果的图片：

比较：

图像从 Android的油漆复制：.measureText（）VS .getTextBounds（）

请注意在第一张照片的文本上方的间距。任何想法可能会导致什么呢？或者测量绘制字符串的高度有其他方法？

下面是的onDraw方法：

  @覆盖
公共无效的onDraw（帆布油画）{
// canvas.drawColor（color_Z1）;
// r.set（0，0，（int）的（宽*进展），高度）;
// paint.setColor（color_Z2）;
//// canvas.drawRect（R，漆）;
// textPaint.getTextBounds（文字，0，text.length（），R）;
// canvas.drawRect（R，漆）;
// canvas.drawText（文字，0，r.height（），textPaint）;    最后一个String =你好，我是一些文本。！     涂料P =新的油漆（）;
     矩形边界=新的矩形（）;
     p.setTextSize（60）;     p.getTextBounds（S，0，s.length（），边界）;
     浮MT = p.measureText（S）;
     INT体重= bounds.width（）;     Log.i（LCG的String.format（
          measureText％F，getTextBounds％D（％S），
          公吨，
          体重，bounds.toShortString（））
      ）;
     bounds.offset（0，-bounds.top）;
     p.setStyle（Style.STROKE）;
     canvas.drawColor（0xff000080）;
     p.setColor（为0xffff0000）;
     canvas.drawRect（边界，P）;
     p.setColor（0xff00ff00）;
     canvas.drawText（S，0，bounds.bottom页）;
}
 

解决方案

我因此未测试code，但我没有看到有Paint.getTextBounds（）的任何问题：

 公共类TextBoundsTest扩展视图{
    私人涂料粉刷;
    私人矩形边界;    公共TextBoundsTest（上下文的背景下）{
        超级（上下文）;
        油漆=新的油漆（Paint.ANTI_ALIAS_FLAG）;
        paint.setTextSize（32）;
        边界=新的矩形（）;
    }    @覆盖
    保护无效的onDraw（帆布油画）{
        字符串文本=这是我的文字;
        paint.getTextBounds（文字，0，text.length（），边界）;
        Log.d（TAG的onDraw+界）;        INT X =（的getWidth（） -  bounds.width（））/ 2;
        诠释Y = 70;        paint.setColor（0xff008800）;
        bounds.offset（X，Y​​）;
        canvas.drawRect（边界，油漆）;        paint.setColor（0xffeeeeee）;
        canvas.drawText（文字，X，Y，油漆）;
    }
}
 

在Activity.onCreate补充一点：

  TextBoundsTest视图=新TextBoundsTest（本）;
的setContentView（视图）;
 

的结果为：

EDIT: The problem came from the emulator, the error did not appear on a real device :(

I'm trying to draw some text in a custom view and must there for measure it but the value of the Paint.getTextBounds() returns a height which is about 30% higher then the actual text which gives everything a quirky look.

I found this: Android Paint: .measureText() vs .getTextBounds() and tried to add the solution code to my own onDraw and saw that i the same measuring error as in my code. Here is a picture of the result:

Compare with: The image is copied from Android Paint: .measureText() vs .getTextBounds()

Note the spacing above the text in the first picture. Any Ideas what might be causing this? Or are there alternative ways to measure height of a drawn string?

Here is the onDraw method:

@Override 
public void onDraw(Canvas canvas){
//      canvas.drawColor(color_Z1);
//      r.set(0, 0, (int)(width*progress), height);
//      paint.setColor(color_Z2);
////        canvas.drawRect(r, paint);
//      textPaint.getTextBounds(text, 0, text.length(), r);
//      canvas.drawRect(r, paint);
//      canvas.drawText(text, 0, r.height(), textPaint);

    final String s = "Hello. I'm some text!";

     Paint p = new Paint();
     Rect bounds = new Rect();
     p.setTextSize(60);

     p.getTextBounds(s, 0, s.length(), bounds);
     float mt = p.measureText(s);
     int bw = bounds.width();

     Log.i("LCG", String.format(
          "measureText %f, getTextBounds %d (%s)",
          mt,
          bw, bounds.toShortString())
      );
     bounds.offset(0, -bounds.top);
     p.setStyle(Style.STROKE);
     canvas.drawColor(0xff000080);
     p.setColor(0xffff0000);
     canvas.drawRect(bounds, p);
     p.setColor(0xff00ff00);
     canvas.drawText(s, 0, bounds.bottom, p);
}

解决方案

i didnot test your code but i dont see any problems with Paint.getTextBounds():

public class TextBoundsTest extends View {
    private Paint paint;
    private Rect bounds;

    public TextBoundsTest(Context context) {
        super(context);
        paint = new Paint(Paint.ANTI_ALIAS_FLAG);
        paint.setTextSize(32);
        bounds = new Rect();
    }

    @Override
    protected void onDraw(Canvas canvas) {
        String text = "this is my text";
        paint.getTextBounds(text, 0, text.length(), bounds);
        Log.d(TAG, "onDraw " + bounds);

        int x = (getWidth() - bounds.width()) / 2;
        int y = 70;

        paint.setColor(0xff008800);
        bounds.offset(x, y);
        canvas.drawRect(bounds, paint);

        paint.setColor(0xffeeeeee);
        canvas.drawText(text, x, y, paint);
    }
}

add this in Activity.onCreate:

TextBoundsTest view = new TextBoundsTest(this);
setContentView(view);

the result is:

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