Question

旋转时我的程序运行良好无限制缩放或仅限制缩放而不旋转。这是我的代码的一部分：

} else if (mode == ZOOM) {
            float newDist = spacing(event);
            matrix.set(savedMatrix);
            if (newDist > 10f) {
                float scale = newDist / oldDist;
                matrix.getValues(mValues1);
                float currentScale = mValues1[0];
                if (currentScale * scale < MIN_ZOOM) {
                    scale = MIN_ZOOM / currentScale;
                } else if (currentScale * scale > MAX_ZOOM) {
                    scale = MAX_ZOOM / currentScale;
                }
                matrix.postScale(scale, scale, mid.x, mid.y);
                matrix.getValues(mValues1);
                Log.e("ZOOM", "scale " + mValues1[0]);
            }

            /*
             * uncomment to enable rotating
             * this function conflicts with zooming limitation
             */
            if (lastEvent != null) {
                newRot = rotation(event);
                float r = newRot - d;
                matrix.postRotate(r, mid.x, mid.y);
                matrix.getValues(mValues1);
                Log.e("ROTATE", " scale " + mValues1[0]);
            }
        }

我认为在执行maxtrix.postRotate之后出现了错误，mValues1 [0] - 缩放值会被更改，并且在下一次循环中，currentScale也会被更改，因此限制缩放检查会出错。给我一些想法。感谢任何帮助：）

Answer 1

我通过其他方式修复了错误。我没有使用currentScale的矩阵值：

float currentScale = mValues1[0];

我使用其他全局变量＆＃34; previsousScale＆＃34;如下所示：

case MotionEvent.ACTION_POINTER_UP:
        // second finger lifted
        mode = NONE;
        lastEvent = null;
        previousScale *= tempScale;
        if (previousScale > MAX_ZOOM)
            previousScale = MAX_ZOOM;
        else if (previousScale < MIN_ZOOM)
            previousScale = MIN_ZOOM;
        break;

以及MotionEvent.ACTION_MOVE：

} else if (mode == ZOOM) {
            float newDist = spacing(event);
            matrix.set(savedMatrix);
            if (newDist > 10f) {
                tempScale = newDist / oldDist;
                if (previousScale * tempScale < MIN_ZOOM) {
                    tempScale = MIN_ZOOM / previousScale;
                } else if (previousScale * tempScale > MAX_ZOOM) {
                    tempScale = MAX_ZOOM / previousScale;
                }
                matrix.postScale(tempScale, tempScale, mid.x, mid.y);
            }

            if (lastEvent != null) {
                 newRot = rotation(event);
                 float r = newRot - d;
                 matrix.postRotate(r, mid.x, mid.y);
            }
        }

Android：旋转和放大之间的冲突限制图像视图的缩放

1 个答案: