Java Android Studio更新现在会出现渲染问题
自从Android Studio几天前更新以来,我一直遇到渲染问题,Emulator无法运行应用程序,并且一直崩溃。我相信我一直用于paintView的代码现在可能已经被严重弃用了?一堆问题是:Java Android Studio更新现在会出现渲染问题,java,android,paint,Java,Android,Paint,自从Android Studio几天前更新以来,我一直遇到渲染问题,Emulator无法运行应用程序,并且一直崩溃。我相信我一直用于paintView的代码现在可能已经被严重弃用了?一堆问题是: java.lang.NullPointerException at com.example.drawnfire.paintView.onDraw_Original(paintView.java:112) at com.example.drawnfire.paintView.onDraw(paintVie
java.lang.NullPointerException
at com.example.drawnfire.paintView.onDraw_Original(paintView.java:112)
at com.example.drawnfire.paintView.onDraw(paintView.java)
at android.view.View.draw_Original(View.java:21443)
at android.view.View_Delegate.draw(View_Delegate.java:56)
at android.view.View.draw(View.java:21417)
at android.view.View.draw_Original(View.java:21317)
at android.view.View_Delegate.draw(View_Delegate.java:68)
at android.view.View.draw(View.java:21089)
at android.view.ViewGroup.drawChild(ViewGroup.java:4388)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149)
at androidx.constraintlayout.widget.ConstraintLayout.dispatchDraw(ConstraintLayout.java:1963)
at android.view.View.draw_Original(View.java:21315)
at android.view.View_Delegate.draw(View_Delegate.java:68)
at android.view.View.draw(View.java:21089)
at android.view.ViewGroup.drawChild(ViewGroup.java:4388)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149)
at android.view.View.draw_Original(View.java:21315)
at android.view.View_Delegate.draw(View_Delegate.java:68)
at android.view.View.draw(View.java:21089)
at android.view.ViewGroup.drawChild(ViewGroup.java:4388)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149)
at android.view.View.draw_Original(View.java:21315)
at android.view.View_Delegate.draw(View_Delegate.java:68)
at android.view.View.draw(View.java:21089)
at android.view.ViewGroup.drawChild(ViewGroup.java:4388)
at android.view.ViewGroup.dispatchDraw(ViewGroup.java:4149)
at android.view.View.draw_Original(View.java:21446)
at android.view.View_Delegate.draw(View_Delegate.java:56)
at android.view.View.draw(View.java:21417)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.renderAndBuildResult(RenderSessionImpl.java:552)
at com.android.layoutlib.bridge.impl.RenderSessionImpl.render(RenderSessionImpl.java:449)
at com.android.layoutlib.bridge.BridgeRenderSession.render(BridgeRenderSession.java:123)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:143)
at com.android.ide.common.rendering.api.RenderSession.render(RenderSession.java:125)
at com.android.tools.idea.rendering.RenderTask.lambda$null$11(RenderTask.java:966)
at java.util.concurrent.CompletableFuture$AsyncSupply.run(CompletableFuture.java:1604)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
这里所指的代码是:
import android.annotation.SuppressLint;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Paint;
import android.graphics.Path;
import android.util.AttributeSet;
import android.util.DisplayMetrics;
import android.view.MotionEvent;
import android.view.View;
import android.view.ViewGroup.LayoutParams;
import android.widget.Toast;
import java.util.ArrayList;
public class paintView extends View {
public static int BRUSH_SIZE = 10;
public static final int DEFAULT_COLOR = Color.RED;
public static final int DEFAULT_BG_COLOR = Color.WHITE;
private static final float TOUCH_TOLERANCE = 4;
private float mX, mY;
public LayoutParams params;
private Path mPath;
private Paint mPaint;
private int currentColor;
private int backgroundColor = DEFAULT_BG_COLOR;
private int strokeWidth;
private Bitmap mBitmap;
private Canvas mCanvas;
private Paint mBitmapPaint = new Paint(Paint.DITHER_FLAG);
private ArrayList<Draw> paths = new ArrayList<>();
private ArrayList<Draw> undo = new ArrayList<>();
public paintView(Context context) {
super(context);
init();
}
public paintView(Context context, AttributeSet attrs) {
super(context, attrs);
init();
}
public paintView(Context context, AttributeSet attrs, int defStyle) {
super(context, attrs, defStyle);
init();
}
private void init() {
mPaint = new Paint();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(DEFAULT_COLOR);
mPaint.setStyle(Paint.Style.STROKE);
mPaint.setStrokeJoin(Paint.Join.ROUND);
mPaint.setStrokeCap(Paint.Cap.ROUND);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
params = new LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT);
}
public void clear() {
backgroundColor = DEFAULT_BG_COLOR;
paths.clear();
invalidate();
}
public void undo() {
if (paths.size() > 0) {
undo.add(paths.remove(paths.size() - 1));
invalidate(); // add
} else {
Toast.makeText(getContext(), "Nothing to undo", Toast.LENGTH_LONG).show();
}
}
public void redo () {
if (undo.size() > 0) {
paths.add(undo.remove(undo.size() - 1));
invalidate(); // add
} else {
Toast.makeText(getContext(), "Nothing to undo", Toast.LENGTH_LONG).show();
}
}
public void setStrokeWidth (int width) {
strokeWidth = width;
}
public void setColor (int color) {
currentColor = color;
}
public void initialise(DisplayMetrics displayMetrics) {
int height = displayMetrics.heightPixels;
int width = displayMetrics.widthPixels;
mBitmap = Bitmap.createBitmap(width, height, Bitmap.Config.ARGB_8888);
mCanvas = new Canvas(mBitmap);
currentColor = DEFAULT_COLOR;
strokeWidth = BRUSH_SIZE;
}
protected void onDraw(Canvas canvas) {
canvas.save();
mCanvas.drawColor(backgroundColor);
for (Draw draw : paths) {
mPaint.setColor(draw.color);
mPaint.setStrokeWidth(draw.strokeWidth);
mPaint.setMaskFilter(null);
mCanvas.drawPath(draw.path, mPaint);
}
canvas.drawBitmap(mBitmap, 0, 0, mBitmapPaint);
canvas.restore();
}
private void touchStart(float x, float y) {
mPath = new Path();
Draw draw = new Draw(currentColor, strokeWidth, mPath);
paths.add(draw);
mPath.reset();
mPath.moveTo(x, y);
mX = x;
mY = y;
}
private void touchMove(float x, float y) {
float dx = Math.abs(x - mX);
float dy = Math.abs(y - mY);
if (dx >= TOUCH_TOLERANCE || dy >= TOUCH_TOLERANCE) {
mPath.quadTo(mX, mY, (x + mX) / 2, (y + mY) / 2);
mX = x;
mY = y;
}
}
private void touchUp() {
mPath.lineTo(mX, mY);
}
@SuppressLint("ClickableViewAccessibility")
@Override
public boolean onTouchEvent(MotionEvent event) {
float x = event.getX();
float y = event.getY();
switch (event.getAction()) {
case MotionEvent.ACTION_DOWN:
touchStart(x, y);
invalidate();
break;
case MotionEvent.ACTION_UP:
touchUp();
invalidate();
break;
case MotionEvent.ACTION_MOVE:
touchMove(x, y);
invalidate();
break;
}
return true;
}
}
导入android.annotation.SuppressLint;
导入android.content.Context;
导入android.graphics.Bitmap;
导入android.graphics.Canvas;
导入android.graphics.Color;
导入android.graphics.Paint;
导入android.graphics.Path;
导入android.util.AttributeSet;
导入android.util.DisplayMetrics;
导入android.view.MotionEvent;
导入android.view.view;
导入android.view.ViewGroup.LayoutParams;
导入android.widget.Toast;
导入java.util.ArrayList;
公共类paintView扩展了视图{
公共静态int笔刷大小=10;
公共静态最终int默认值_COLOR=COLOR.RED;
公共静态最终整数默认值\u BG\u COLOR=COLOR.WHITE;
专用静态最终浮动接触公差=4;
私人浮动mX,我的;
公共布局参数;
专用路径mPath;
私人油漆;
私人色彩;
private int backgroundColor=默认背景颜色;
私有内冲程宽度;
私有位图mBitmap;
私人帆布mCanvas;
专用油漆mBitmapPaint=新油漆(油漆抖动标志);
私有ArrayList路径=新ArrayList();
private ArrayList undo=new ArrayList();
公共paintView(上下文){
超级(上下文);
init();
}
公共画图视图(上下文、属性集属性){
超级(上下文,attrs);
init();
}
公共画图视图(上下文、属性集属性、int-defStyle){
超级(上下文、属性、定义样式);
init();
}
私有void init(){
mPaint=新油漆();
mPaint.setAntiAlias(true);
mPaint.setDither(true);
mPaint.setColor(默认颜色);
mPaint.setStyle(油漆、样式、笔划);
mPaint.setStrokeJoin(油漆.连接.圆形);
mPaint.setStrokeCap(油漆盖圆形);
mPaint.setXfermode(null);
mPaint.setAlpha(0xff);
params=新的LayoutParams(LayoutParams.MATCH_父级,LayoutParams.WRAP_内容);
}
公共空间清除(){
backgroundColor=默认的背景颜色;
清除路径();
使无效();
}
公共作废撤消(){
if(path.size()>0){
undo.add(path.remove(path.size()-1));
无效();//添加
}否则{
Toast.makeText(getContext(),“无需撤消”,Toast.LENGTH_LONG.show();
}
}
公共无效重做(){
如果(undo.size()>0){
add(undo.remove(undo.size()-1));
无效();//添加
}否则{
Toast.makeText(getContext(),“无需撤消”,Toast.LENGTH_LONG.show();
}
}
公共无效设置行程宽度(整数宽度){
冲程宽度=宽度;
}
公共void setColor(int-color){
当前颜色=颜色;
}
公共无效初始化(DisplayMetrics DisplayMetrics){
int height=displayMetrics.heightPixels;
int width=displayMetrics.widthPixels;
mBitmap=Bitmap.createBitmap(宽度、高度、Bitmap.Config.ARGB_8888);
mCanvas=新画布(mBitmap);
currentColor=默认颜色;
笔划宽度=画笔大小;
}
受保护的void onDraw(画布){
canvas.save();
mCanvas.drawColor(背景色);
用于(绘制:路径){
mPaint.setColor(draw.color);
mPaint.设置行程宽度(绘制行程宽度);
mPaint.setMaskFilter(null);
mCanvas.drawPath(draw.path,mPaint);
}
drawBitmap(mBitmap,0,0,mbitMapPoint);
canvas.restore();
}
专用void touchStart(浮点x、浮点y){
mPath=新路径();
绘制=新绘制(当前颜色、笔划宽度、mPath);
路径。添加(绘制);
mPath.reset();
移动到(x,y)的速度;
mX=x;
mY=y;
}
私有无效触摸移动(浮动x、浮动y){
float dx=Math.abs(x-mX);
float dy=Math.abs(y-mY);
如果(dx>=接触公差| | dy>=接触公差){
兆帕四分之一秒(mX,mY,(x+mX)/2,(y+mY)/2);
mX=x;
mY=y;
}
}
私人修补{
mPath.lineTo(mX,mY);
}
@SuppressLint(“ClickableViewAccessibility”)
@凌驾
公共布尔onTouchEvent(运动事件){
float x=event.getX();
float y=event.getY();
开关(event.getAction()){
case MotionEvent.ACTION\u DOWN:
touchStart(x,y);
使无效();
打破
case MotionEvent.ACTION\u UP:
修补();
使无效();
打破
case MotionEvent.ACTION\u移动:
touchMove(x,y);
使无效();
打破
}
返回true;
}
}
很抱歉,这是多久了,但我已经失去了理智。Android Studio 4.0.0工作正常,但4.1.0和4.2.0出现错误,不稳定。因此,请使用Android Studio 4.0.0谢谢您使用的是安卓4.1.0稳定版吗?是的,我是。我遇到了这个问题,甚至重新安装了当前的android studio以防万一。通过设置断点检查您的mPaint或mCanvas是否为空。