Question

问题：
当我在activity中使用我的自定义视图时，然后我更改自定义视图的translateY。然后，自定义视图绘制在状态栏上。

当我删除CustomView.java中的代码canvas.clipRect(0, 0, getWidth(), getHeight(), Region.Op.REPLACE);时，它会没问题但在实际情况中，我需要clipRect函数来限制。那么，我该如何计算剪辑范围。

请帮我修理一下。

布局文件：

<RelativeLayout
    android:id="@+id/action_bar"
    android:layout_width="match_parent"
    android:layout_height="40dp"
    android:background="#00e0e0">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerInParent="true"
        android:text="Test Title" />

    <TextView
        android:id="@+id/text"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerVertical="true"
        android:text="up"
        android:textSize="32dp" />

</RelativeLayout>

<cn.bangnijiao.testunitdemo.CustomView
    android:id="@+id/counterView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_below="@id/action_bar"
    android:layout_centerHorizontal="true" />

代码：

public class YActivity extends Activity {

TextView up;
CustomView customView;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_y);

    up = (TextView) findViewById(R.id.text);
    customView = (CustomView) findViewById(R.id.counterView);

    up.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            customView.setTranslationY(customView.getTranslationY() - 20);
        }
    });

    findViewById(R.id.action_bar).bringToFront();
}

}

CustomView代码：

public class CustomView extends View {

private Paint mPaint;
int size = 120;

public CustomView(Context context, AttributeSet attrs) {
    super(context, attrs);
    mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
}

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    drawSeparatorsAndBackground(canvas);
}

private void drawSeparatorsAndBackground(Canvas canvas) {

    mPaint.setColor(Color.YELLOW);
    canvas.drawRect(0, 0, getWidth(), getHeight(), mPaint);

    canvas.clipRect(0, 0, getWidth(), getHeight(), Region.Op.REPLACE);

    mPaint.setColor(Color.BLACK);

    int verticalCount = (getWidth() / size);
    float[] verticalLines = new float[verticalCount * 4];

    for (int i = 0; i < verticalCount; i++) {
        verticalLines[i * 4 + 0] = i * size;
        verticalLines[i * 4 + 1] = 0;
        verticalLines[i * 4 + 2] = i * size;
        verticalLines[i * 4 + 3] = getHeight();
    }
    canvas.drawLines(verticalLines, mPaint);

    int hourHorizontalCount = (getHeight() / size);
    float[] hourHorizontalLines = new float[hourHorizontalCount * 4];

    for (int i = 0; i < hourHorizontalCount; i++) {
        hourHorizontalLines[i * 4 + 0] = 0;
        hourHorizontalLines[i * 4 + 1] = i * size;
        hourHorizontalLines[i * 4 + 2] = getWidth();
        hourHorizontalLines[i * 4 + 3] = i * size;
    }
    canvas.drawLines(hourHorizontalLines, mPaint);
}

}

Answer 1

尝试canvas.save（）和canvas.restore（）

@Override
protected void onDraw(Canvas canvas) {
    super.onDraw(canvas);
    int saveCount = canvas.save();
    drawSeparatorsAndBackground(canvas);
    canvas.restoreToCount(saveCount);
}

Android自定义栏：绘制状态栏

1 个答案: