android 自定义surface 如何显示在屏幕上
时间: 2024-02-26 21:56:20 浏览: 289
Android自定义SurfaceView实现画板功能
要将自定义的Surface显示在Android屏幕上,需要在自定义的SurfaceView中重写surfaceCreated()、surfaceChanged() 和surfaceDestroyed()方法。具体步骤如下:
1. 在XML布局文件中添加自定义的SurfaceView。
2. 创建自定义的SurfaceView类,并重写surfaceCreated()、surfaceChanged() 和surfaceDestroyed()方法。
3. 在surfaceCreated()方法中获取SurfaceHolder对象,通过SurfaceHolder对象获取Canvas对象,并在Canvas对象上绘制需要显示的内容。
4. 在surfaceChanged()方法中设置SurfaceView的宽高和像素格式。
5. 在surfaceDestroyed()方法中释放资源,如停止绘制线程等。
6. 在Activity中获取自定义的SurfaceView对象,并调用其方法(如startDraw()方法)开始绘制。
示例代码:
```java
// 在XML布局文件中添加自定义的SurfaceView
<com.example.customsurfaceview.MySurfaceView
android:id="@+id/my_surface_view"
android:layout_width="match_parent"
android:layout_height="match_parent" />
// 创建自定义的SurfaceView类
public class MySurfaceView extends SurfaceView implements SurfaceHolder.Callback {
private SurfaceHolder mHolder;
private DrawThread mDrawThread;
public MySurfaceView(Context context) {
super(context);
init();
}
public MySurfaceView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public MySurfaceView(Context context, AttributeSet attrs, int defStyleAttr) {
super(context, attrs, defStyleAttr);
init();
}
private void init() {
mHolder = getHolder();
mHolder.addCallback(this);
}
@Override
public void surfaceCreated(SurfaceHolder holder) {
// 获取SurfaceHolder对象
mHolder = holder;
// 开始绘制线程
mDrawThread = new DrawThread(mHolder);
mDrawThread.start();
}
@Override
public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
// 设置SurfaceView的宽高和像素格式
mHolder.setFixedSize(width, height);
mHolder.setFormat(PixelFormat.RGBA_8888);
}
@Override
public void surfaceDestroyed(SurfaceHolder holder) {
// 释放资源
mDrawThread.setRunning(false);
mDrawThread = null;
}
// 绘制线程
private class DrawThread extends Thread {
private SurfaceHolder mHolder;
private boolean mRunning = true;
public DrawThread(SurfaceHolder holder) {
mHolder = holder;
}
public void setRunning(boolean running) {
mRunning = running;
}
@Override
public void run() {
super.run();
while (mRunning) {
Canvas canvas = mHolder.lockCanvas();
// 在Canvas上绘制需要显示的内容
draw(canvas);
mHolder.unlockCanvasAndPost(canvas);
}
}
private void draw(Canvas canvas) {
// 绘制逻辑
}
}
}
// 在Activity中获取自定义的SurfaceView对象,并调用其方法开始绘制
public class MainActivity extends AppCompatActivity {
private MySurfaceView mSurfaceView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mSurfaceView = findViewById(R.id.my_surface_view);
}
@Override
protected void onResume() {
super.onResume();
mSurfaceView.startDraw();
}
}
```
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