Question

我正在尝试制作一个无效的简单自定义视图。我从布局资源文件中查看了自定义视图类。但它不起作用。谁能告诉我问题出在哪里。

public class WriteOnScreenActivity extends Activity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
    }

}

public class CustomView extends View {

    private Paint paint;

    public TouchEventView(Context context) {
        super(context);

        paint = new Paint();
        paint.setColor(Color.RED);
        paint.setTextSize(25);
        paint.setAntiAlias(true);
    }

    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    canvas.drawText("Hello World", 5, 30, paint);   
    }

}

<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent" >

       <com.example.touch.CustomView
           android:id="@+id/TouchEventView"
           android:layout_width="fill_parent"
           android:layout_height="fill_parent" />

</RelativeLayout>

Answer 1

将TouchEventView类的定义移动到新文件中。

这是修复。

public class TouchEventView extends View {

    private Paint paint;

    public TouchEventView(Context context, AttributeSet attrs, int defStyle) {
        super(context, attrs, defStyle);
        setup(context, attrs, defStyle);
    }

    public TouchEventView(Context context, AttributeSet attrs) {
        super(context, attrs);
        setup(context, attrs, 0);
    }

    public TouchEventView(Context context) {
        super(context);

      setup(context, null, 0);

    }

    private void setup(Context context, AttributeSet attrs, int defStyle)
    {

            paint = new Paint();
            paint.setColor(Color.RED);
            paint.setTextSize(25);
            paint.setAntiAlias(true);
    }

    protected void onDraw(Canvas canvas) {
        super.onDraw(canvas);
    canvas.drawText("Hello World", 5, 30, paint);   
    }

}

简单自定义视图不起作用

1 个答案: