基本上我想使用SurfaceView进行动画制作。因此该类实现了Runnable。为了实验,我想绘制一个圆圈。但是,它只显示黑屏。
我已经好几天了。真的很感激,如果有人可以提供帮助。
MainActivity类
public class MainActivity extends Activity {
private Bitmap Liquid;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature (Window.FEATURE_NO_TITLE);
getWindow().setFlags(WindowManager.LayoutParams.FLAG_FULLSCREEN,
WindowManager.LayoutParams.FLAG_FULLSCREEN);
DrawStripFrame D1 = new DrawStripFrame(this);
setContentView(D1);
DrawStripFrame类
public class DrawStripFrame extends SurfaceView implements Runnable{
private SurfaceHolder holder;
private boolean running = true;
public DrawStripFrame (Context context){
super (context);
holder = getHolder();
}
@Override
public void run(){
while(running){
if(holder.getSurface().isValid()){
Canvas c = holder.lockCanvas();
c.drawARGB(0, 0, 0, 0);
Paint redPaint = new Paint();
redPaint.setColor(Color.RED);
c.drawCircle(100, 100, 30, redPaint);
holder.unlockCanvasAndPost(c);
}
}
}
}
答案 0 :(得分:2)
我有同样的问题。我在不同的模拟器上测试了我的APP。
这是我的MainActivity类
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
public class MainActivity extends AppCompatActivity {
private SurfaceViewTest test;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
test = new SurfaceViewTest(this);
setContentView(test);
}
@Override
protected void onResume() {
super.onResume();
test.resume();
}
}
SurfaceViewTest.java
import android.content.Context;
import android.graphics.Canvas;
import android.graphics.Color;
import android.view.SurfaceView;
public class SurfaceViewTest extends SurfaceView implements Runnable {
private Thread thread;
volatile boolean running;
public SurfaceViewTest(Context context) {
super(context);
}
@Override
public void run() {
while(running) {
draw();
}
}
private void draw(){
if(getHolder().getSurface().isValid()) {
Canvas canvas = getHolder().lockCanvas();
canvas.drawColor(Color.argb(255, 255, 0, 0));
getHolder().unlockCanvasAndPost(canvas);
}
}
public void resume() {
running = true;
thread = new Thread(this);
thread.start();
}
public void pause() {
running = false;
while (thread.isAlive()) {
try {
thread.join(100);
if(thread.isAlive()) {
thread.interrupt();
thread.join();
}
} catch (InterruptedException e) {
e.printStackTrace();
}
}
}
}
styles.xml
<resources>
<!-- Base application theme. -->
<style name="AppTheme" parent="Theme.AppCompat">
<!-- Customize your theme here. -->
<item name="colorPrimary">@color/colorPrimary</item>
<item name="colorPrimaryDark">@color/colorPrimaryDark</item>
<item name="colorAccent">@color/colorAccent</item>
<item name="android:windowFullscreen">true</item>
</style>
<style name="Theme.AppCompat.Light.NoActionBar.FullScreen" parent="@style/Theme.AppCompat.Light">
<item name="windowNoTitle">true</item>
<item name="windowActionBar">false</item>
<item name="android:windowFullscreen">true</item>
<item name="android:windowContentOverlay">@null</item>
<item name="android:background">#000000</item><!-- Remove it to fix the problem -->
</style>
</resources>
我解决了从styles.xml
中删除项目背景的问题<item name="android:background">#00000</item>
alpha通道看起来有问题。
答案 1 :(得分:1)
通过更改while循环来解决问题:
while(running){
if(!holder.getSurface().isValid())
continue;
Canvas c = holder.lockCanvas();
c.drawARGB(0, 0, 0, 0);
Paint redPaint = new Paint();
redPaint.setColor(Color.RED);
c.drawCircle(100, 100, 30, redPaint);
holder.unlockCanvasAndPost(c);
}
当表面无效时,continue语句将控制权发送回循环的顶部。只有当surface有效时,才会执行下面的块。
答案 2 :(得分:0)
在DrawStripFrame构造函数中,将alpha设置为零。像这样:
public DrawStripFrame (Context context){
super (context);
holder = getHolder();
setAlpha(0); // this is the secret
}
答案 3 :(得分:0)
确保已给出 Camera Permission
,否则SurfaceView会显示黑屏。
答案 4 :(得分:0)
SurfaceView基本上不支持动画,滚动等。因此,您应该使用TextureView。