在 OnClickListener Android 上刷新 SurfaceView-->Canvas

Question

我希望每次按下屏幕上的矩形按钮之一来改变位置。或刷新整个 SurfaceView。

应用程序似乎在运行，但矩形不随计数器改变位置。

非常感谢。

野兔是xml代码：

<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" >
<SurfaceView
    android:id="@+id/surface"
    android:layout_width="match_parent"
    android:layout_height="match_parent" />
<TextView
    android:id="@+id/textView1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_centerHorizontal="true"
    android:layout_centerVertical="true"
    android:text="@string/hello_world"
    tools:context=".MainActivity" />
<Button
    android:id="@+id/l"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentLeft="true"
    android:layout_alignParentTop="true"
    android:layout_marginLeft="16dp"
    android:text="L" />
<Button
    android:id="@+id/r"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignLeft="@+id/textView1"
    android:layout_alignParentTop="true"
    android:layout_marginLeft="19dp"
    android:text="R" />
</RelativeLayout>

这里是 Java：

package com.example.rectangle;

import android.app.Activity;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.os.Bundle;
import android.view.SurfaceHolder;
import android.view.SurfaceHolder.Callback;
import android.view.SurfaceView;
import android.view.View;
import android.view.Window;
import android.view.WindowManager;
import android.widget.Button;
import android.widget.TextView;

public class MainActivity extends Activity {
DrawView drawView;
Paint paint = new Paint();
int w, h, edge, axis_w;
int counter;
Button add, sub;
TextView display;

@Override
public void onCreate(Bundle savedInstanceState) {
    requestWindowFeature(Window.FEATURE_NO_TITLE);
    this.getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
            WindowManager.LayoutParams.FLAG_FULLSCREEN);
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    counter = 0;
    add = (Button) findViewById(R.id.r);
    sub = (Button) findViewById(R.id.l);
    display = (TextView) findViewById(R.id.textView1);

    add.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub
            counter += 10;
            display.setText("Total is" + counter);

        }
    });

    sub.setOnClickListener(new View.OnClickListener() {

        public void onClick(View v) {
            // TODO Auto-generated method stub
            counter -= 10;
            display.setText("Total is" + counter);
        }
    });

    SurfaceView surface = (SurfaceView) findViewById(R.id.surface);

    surface.getHolder().addCallback(new Callback() {

        public void surfaceCreated(SurfaceHolder holder) {

            Canvas canvas = holder.lockCanvas();

            w = canvas.getWidth();
            h = canvas.getHeight();
            edge = 5;
            axis_w = 3;
            // canvas.drawRect(left, top, right, bottom, paint)
            // Background
            paint.setColor(Color.rgb(255, 255, 255));
            canvas.drawRect(0, 0, w, h, paint);
            // Canvas Background Color
            paint.setColor(Color.rgb(0, 206, 209));
            // Borders
            canvas.drawRect(0, 0, w, edge, paint);
            canvas.drawRect(0, h - edge, w, h, paint);
            canvas.drawRect(0, 0, edge, h, paint);
            canvas.drawRect(w - edge, 0, w, h, paint);
            // Axis
            canvas.drawRect(((w - axis_w) / 2) + counter, 0,
                    ((w + axis_w) / 2) + counter, h, paint);
            canvas.drawRect(0, (h - axis_w) / 2, w, (h + axis_w) / 2, paint);

            holder.unlockCanvasAndPost(canvas);
        }

        public void surfaceDestroyed(SurfaceHolder holder) {
        }

        public void surfaceChanged(SurfaceHolder holder, int format,
                int width, int height) {
        }
    });
}
}

Answer 1

好的。尝试另一种解决方案。尝试制作自己的 View 类，您将在其中绘制矩形。我为你准备了一些代码。根据您的需要进行定制。

Simlpe XML

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:orientation="vertical"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:id="@+id/mainL"
    >
<Button
    android:layout_width="fill_parent"
    android:layout_height="wrap_content"
    android:text="Hello World, MainActivity"
    android:id="@+id/button"
    />
</LinearLayout>

和java代码

public class MainActivity extends Activity
{
    MyRectg myRectg;
    @Override
    public void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        myRectg = new MyRectg(this);
        ((LinearLayout)findViewById(R.id.mainL)).addView(myRectg);
        ((Button)findViewById(R.id.button)).setOnClickListener(new View.OnClickListener() {

        public void onClick(View arg0)
        {
            myRectg.invalidate();
        }
    });
}

public class MyRectg extends View
{
    public MyRectg(Context c)
    {
        super(c);
    }

    @Override
    public void onDraw(Canvas c)
    {
        //this simulate new positions calculating
        Random rnd = new Random();
        Paint p = new Paint();
        p.setColor(Color.GREEN);
        c.drawRect(rnd.nextFloat()*100, rnd.nextFloat()*500, rnd.nextFloat()*300, rnd.nextFloat()*500, p);
    }
}

现在，当您单击按钮时画布会随机移动。这是你想要的吗？

Answer 2

尝试在 SurfaceView 上调用 Invalidate 方法以在每次位置更改后刷新它。

编辑：

并将位置计算从surfaceCreated移动到surfaceChanged方法。