SWT Canvas绘制动态图的问题

Posted 2023-05-18

程序中可以每过0.1s可以得到一组坐标数据，但是我如何在已经有的canvas上更新呢？我想要一步一步的画出来，没过一个0.1s画一条线，但是怎么实现呢？
更新语句是否一定要写在shell.open()之前呢？

只要给点提示就可以了。。。
我发现很多可以动态刷新图片的程序都是以addlistener的方法做的，以上的问题可以用这个方法吗？如果可以的话，event又应该算作什么呢？
求达人指点一下啊，谢谢了！

参考技术A 将程序显示逻辑和数据部分开，监听数据变化，然后重绘显示组件追问

谢谢你的回复！不过如何监听数据变化呢？比如说我数据就是Global_data，具体的语句应该是什么？

如何在Canvas上显示gif动画 SWT

1、首先，重写控件View,自定义一个展示gif图的GifView，代码如下：
package net.loonggg.gif.view;

import net.loonggg.gif.R;
import android.annotation.SuppressLint;
import android.content.Context;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Movie;
import android.os.Build;
import android.util.AttributeSet;
import android.view.View;

public class GifView extends View

/**
* 默认为1秒
*/
private static final int DEFAULT_MOVIE_DURATION = 1000;

private int mMovieResourceId;

private Movie mMovie;

private long mMovieStart;

private int mCurrentAnimationTime = 0;

private float mLeft;

private float mTop;

private float mScale;

private int mMeasuredMovieWidth;

private int mMeasuredMovieHeight;

private boolean mVisible = true;

private volatile boolean mPaused = false;

public GifView(Context context)
this(context, null);


public GifView(Context context, AttributeSet attrs)
this(context, attrs, R.styleable.CustomTheme_gifViewStyle);


public GifView(Context context, AttributeSet attrs, int defStyle)
super(context, attrs, defStyle);
setViewAttributes(context, attrs, defStyle);


@SuppressLint("NewApi")
private void setViewAttributes(Context context, AttributeSet attrs,
int defStyle)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.HONEYCOMB)
setLayerType(View.LAYER_TYPE_SOFTWARE, null);

// 从描述文件中读出gif的值，创建出Movie实例
final TypedArray array = context.obtainStyledAttributes(attrs,
R.styleable.GifView, defStyle, R.style.Widget_GifView);
mMovieResourceId = array.getResourceId(R.styleable.GifView_gif, -1);
mPaused = array.getBoolean(R.styleable.GifView_paused, false);
array.recycle();
if (mMovieResourceId != -1)
mMovie = Movie.decodeStream(getResources().openRawResource(
mMovieResourceId));



/**
* 设置gif图资源
*
* @param movieResId
*/
public void setMovieResource(int movieResId)
this.mMovieResourceId = movieResId;
mMovie = Movie.decodeStream(getResources().openRawResource(
mMovieResourceId));
requestLayout();


public void setMovie(Movie movie)
this.mMovie = movie;
requestLayout();


public Movie getMovie()
return mMovie;


public void setMovieTime(int time)
mCurrentAnimationTime = time;
invalidate();


/**
* 设置暂停
*
* @param paused
*/
public void setPaused(boolean paused)
this.mPaused = paused;
if (!paused)
mMovieStart = android.os.SystemClock.uptimeMillis()
- mCurrentAnimationTime;

invalidate();


/**
* 判断gif图是否停止了
*
* @return
*/
public boolean isPaused()
return this.mPaused;


@Override
protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec)
if (mMovie != null)
int movieWidth = mMovie.width();
int movieHeight = mMovie.height();
int maximumWidth = MeasureSpec.getSize(widthMeasureSpec);
float scaleW = (float) movieWidth / (float) maximumWidth;
mScale = 1f / scaleW;
mMeasuredMovieWidth = maximumWidth;
mMeasuredMovieHeight = (int) (movieHeight * mScale);
setMeasuredDimension(mMeasuredMovieWidth, mMeasuredMovieHeight);
else
setMeasuredDimension(getSuggestedMinimumWidth(),
getSuggestedMinimumHeight());



@Override
protected void onLayout(boolean changed, int l, int t, int r, int b)
super.onLayout(changed, l, t, r, b);
mLeft = (getWidth() - mMeasuredMovieWidth) / 2f;
mTop = (getHeight() - mMeasuredMovieHeight) / 2f;
mVisible = getVisibility() == View.VISIBLE;


@Override
protected void onDraw(Canvas canvas)
if (mMovie != null)
if (!mPaused)
updateAnimationTime();
drawMovieFrame(canvas);
invalidateView();
else
drawMovieFrame(canvas);




@SuppressLint("NewApi")
private void invalidateView()
if (mVisible)
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.JELLY_BEAN)
postInvalidateOnAnimation();
else
invalidate();




private void updateAnimationTime()
long now = android.os.SystemClock.uptimeMillis();
// 如果第一帧，记录起始时间
if (mMovieStart == 0)
mMovieStart = now;

// 取出动画的时长
int dur = mMovie.duration();
if (dur == 0)
dur = DEFAULT_MOVIE_DURATION;

// 算出需要显示第几帧
mCurrentAnimationTime = (int) ((now - mMovieStart) % dur);


private void drawMovieFrame(Canvas canvas)
// 设置要显示的帧，绘制即可
mMovie.setTime(mCurrentAnimationTime);
canvas.save(Canvas.MATRIX_SAVE_FLAG);
canvas.scale(mScale, mScale);
mMovie.draw(canvas, mLeft / mScale, mTop / mScale);
canvas.restore();


@SuppressLint("NewApi")
@Override
public void onScreenStateChanged(int screenState)
super.onScreenStateChanged(screenState);
mVisible = screenState == SCREEN_STATE_ON;
invalidateView();


@SuppressLint("NewApi")
@Override
protected void onVisibilityChanged(View changedView, int visibility)
super.onVisibilityChanged(changedView, visibility);
mVisible = visibility == View.VISIBLE;
invalidateView();


@Override
protected void onWindowVisibilityChanged(int visibility)
super.onWindowVisibilityChanged(visibility);
mVisible = visibility == View.VISIBLE;
invalidateView();



Movie其实管理着GIF动画中的多个帧，只需要通过 setTime() 一下就可以让它在draw()的时候绘出相应的那帧图像。通过当前时间与duration之间的换算关系，是很容易实现GIF动起来的效果。

其次，在xml布局文件中，把这个view定义进去，代码如下：

[html] view plain copy
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_
android:layout_
android:orientation="vertical" >

<net.loonggg.gif.view.GifView
android:id="@+id/gif1"
android:layout_
android:layout_
android:layout_gravity="center_horizontal"
android:enabled="false" />

<net.loonggg.gif.view.GifView
android:id="@+id/gif2"
android:layout_
android:layout_
android:layout_gravity="center_horizontal"
android:enabled="false" />

</LinearLayout>

2、最后，在MainActivity中的使用，代码如下：
package net.loonggg.gif;

import net.loonggg.gif.view.GifView;
import android.app.Activity;
import android.os.Bundle;

public class Gif extends Activity
private GifView gif1, gif2;

@Override
public void onCreate(Bundle savedInstanceState)
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
gif1 = (GifView) findViewById(R.id.gif1);
// 设置背景gif图片资源
gif1.setMovieResource(R.raw.kitty);
gif2 = (GifView) findViewById(R.id.gif2);
gif2.setMovieResource(R.raw.b);
// 设置暂停
// gif2.setPaused(true);



参考技术A 你直接用这条语句就可解决
final JLabel label = new JLabel();
label.setIcon(new ImageIcon("mainback.gif"));
不用去重画什么的.
希望采纳追问

这个是swing的label，可以放在swt的容器里边吗？

参考技术B public class ImageCanvasTest
public static void main(String[] args)
Display display = new Display();
final Shell shell = new Shell(display);
ImageViewer ic = new ImageViewer(shell);

shell.setLayout( new FillLayout());
FileDialog dialog = new FileDialog(shell, SWT.OPEN);
dialog.setText( " Open an image file or cancel " );
String string = dialog.open();

ImageLoader loader = new ImageLoader();
ImageData[] imageDatas = loader.load(string);
if (imageDatas.length == 0 )
return ;
else if (imageDatas.length == 1 )
ic.setImage(imageDatas[ 0 ]);
else
ic.setImages(imageDatas, loader.repeatCount);


ic.pack();
shell.pack();
shell.open();
while ( ! shell.isDisposed())
if ( ! display.readAndDispatch())
display.sleep();

display.dispose();



更详细的教程：http://irving-wei.iteye.com/blog/1090164 参考技术C 将程序显示逻辑和数据部分开，监听数据变化，然后重绘显示组件 参考技术D 1.会根据用途以及变化更符合人体 2.见过一个 第5个回答  2013-04-28 这个需要用多线程控制。 第6个回答  2015-12-16 vmfmj，韩国不好看吧？还比较麻烦！！！