IllegalArgumentException：宽度和高度必须 > 0

Question

我试图在画布中绘制位图，但在 logact 中出现错误。 日志是这样的：

    09-22 16:41:02.081: D/dalvikvm(26969): Late-enabling CheckJNI
09-22 16:41:02.191: D/ActivityThread(26969): setTargetHeapUtilization:0.25
09-22 16:41:02.191: D/ActivityThread(26969): setTargetHeapIdealFree:8388608
09-22 16:41:02.191: D/ActivityThread(26969): setTargetHeapConcurrentStart:2097152
09-22 16:41:03.141: D/AndroidRuntime(26969): Shutting down VM
09-22 16:41:03.141: W/dalvikvm(26969): threadid=1: thread exiting with uncaught exception (group=0x41bb5438)
09-22 16:41:03.171: E/AndroidRuntime(26969): FATAL EXCEPTION: main
09-22 16:41:03.171: E/AndroidRuntime(26969): java.lang.RuntimeException: Unable to start activity ComponentInfo{com.example.prova1/com.example.prova1.MoveBalloon}: java.lang.IllegalArgumentException: width and height must be > 0
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2114)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:2139)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread.access$700(ActivityThread.java:143)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1241)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.os.Handler.dispatchMessage(Handler.java:99)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.os.Looper.loop(Looper.java:137)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread.main(ActivityThread.java:4963)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at java.lang.reflect.Method.invokeNative(Native Method)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at java.lang.reflect.Method.invoke(Method.java:511)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1038)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:805)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at dalvik.system.NativeStart.main(Native Method)
09-22 16:41:03.171: E/AndroidRuntime(26969): Caused by: java.lang.IllegalArgumentException: width and height must be > 0
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.graphics.Bitmap.createBitmap(Bitmap.java:667)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.graphics.Bitmap.createBitmap(Bitmap.java:615)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at com.example.prova1.MoveBalloon.getResizedBitmap(MoveBalloon.java:158)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at com.example.prova1.MoveBalloon.onCreate(MoveBalloon.java:99)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.Activity.performCreate(Activity.java:5184)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1094)
09-22 16:41:03.171: E/AndroidRuntime(26969):    at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:2078)
09-22 16:41:03.171: E/AndroidRuntime(26969):    ... 11 more
09-22 16:41:16.471: I/Process(26969): Sending signal. PID: 26969 SIG: 9

发生错误的类如下：

package com.example.prova1;


import android.app.Activity;
import android.content.Context;
import android.graphics.Bitmap;
import android.graphics.BitmapFactory;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Point;

import android.hardware.SensorManager;
import android.os.Build;
import android.os.Bundle;
import android.util.DisplayMetrics;
import android.view.Display;
import android.view.SurfaceHolder;
import android.view.SurfaceView;
import android.view.WindowManager;

public class MoveBalloon extends Activity {
    Bitmap balloon;
    Bitmap background;
    Bitmap _background;
    DrawBalloon myView;
    float x,y,sensorX, sensorY;
    SensorManager sm;
    Microphone mic;
    int width, height;




public class DrawBalloon extends SurfaceView implements Runnable {

    SurfaceHolder ourHolder ;
    Thread ourThread = null;
    boolean isRunning=true;

    public DrawBalloon(Context context) {
        super(context);
        ourHolder= getHolder();
    }

    public void pause() {
        isRunning=false;
        while(true){
            try{
                ourThread.join();
            } catch (InterruptedException e){
                e.printStackTrace();
            }
            break;
        }
        ourThread=null;
    }

    public void resume(){
        isRunning=true;
        ourThread = new Thread(this);
        ourThread.start();


    }
    @Override
    public void run (){
        while(isRunning){
            if(!ourHolder.getSurface().isValid())
                continue;
            Canvas canvas = ourHolder.lockCanvas();

            updateMic();
            canvas.drawBitmap(background,0,0,null);
            canvas.drawBitmap(balloon, sensorX, sensorY,null);
            ourHolder.unlockCanvasAndPost(canvas);
        }
    }
}



@Override
protected void onCreate(Bundle savedInstanceState) {
    // TODO Auto-generated method stub
    super.onCreate(savedInstanceState);
    /*sm= (SensorManager) getSystemService(Context.SENSOR_SERVICE);
    if(sm.getSensorList(Sensor.TYPE_ACCELEROMETER).size()!=0){
        Sensor s = sm.getSensorList(Sensor.TYPE_ACCELEROMETER).get(0);
        sm.registerListener(this,s ,SensorManager.SENSOR_DELAY_NORMAL);
    }*/
mic = new Microphone();
balloon = BitmapFactory.decodeResource(getResources(), R.drawable.images);
background = BitmapFactory.decodeResource(getResources(), R.drawable.ic_launcher);
sensorX=150;
sensorY=350;
//x=y=sensorX=sensorY=0;
getSize(width,height);
_background = getResizedBitmap(background,height,width);
myView= new DrawBalloon (this);
myView.resume();
setContentView(myView);
}



/*@Override
public void onAccuracyChanged(Sensor sensor, int accuracy) {
    // TODO Auto-generated method stub

}



@Override
public void onSensorChanged(SensorEvent event) {
    // TODO Auto-generated method stub
    try {
        Thread.sleep(20);
    } catch (InterruptedException e) {
        // TODO Auto-generated catch block
        e.printStackTrace();
    }
    sensorX=event.values[0];
    sensorY=event.values[1];

}

*/
public void updateMic(){
int level = mic.getLevel();

    sensorY-=level;
}

@Override
public void onBackPressed() {


    finish();


    }

public Bitmap getResizedBitmap(Bitmap bm, int newHeight, int newWidth) {
    int width = bm.getWidth();
    int height = bm.getHeight();
    float scaleWidth = ((float) newWidth) / width;
    float scaleHeight = ((float) newHeight) / height;

    // Create a matrix for the manipulation
    Matrix matrix = new Matrix();

    // Resize the bit map
    matrix.postScale(scaleWidth, scaleHeight);

    // Recreate the new Bitmap
    Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);
    return resizedBitmap;
}

public void getSize(int x, int y){
WindowManager w = this.getWindowManager();
Display d = w.getDefaultDisplay();
DisplayMetrics metrics = new DisplayMetrics();
d.getMetrics(metrics);
// since SDK_INT = 1;
int widthPixels = metrics.widthPixels;
int heightPixels = metrics.heightPixels;

if (Build.VERSION.SDK_INT >= 14 && Build.VERSION.SDK_INT < 17){
try {
    widthPixels = (Integer) Display.class.getMethod("getRawWidth").invoke(d);
    heightPixels = (Integer) Display.class.getMethod("getRawHeight").invoke(d);
} catch (Exception ignored) {
}
}
// includes window decorations (statusbar bar/menu bar)
if (Build.VERSION.SDK_INT >= 17){
try {
    Point realSize = new Point();
    Display.class.getMethod("getRealSize", Point.class).invoke(d, realSize);
    widthPixels = realSize.x;
    heightPixels = realSize.y;
} catch (Exception ignored) {
}
}

x=widthPixels;
y=heightPixels;
}
}

第 99 行是：

_background = getResizedBitmap(background,height,width);

第 158 行号是：

Bitmap resizedBitmap = Bitmap.createBitmap(bm, 0, 0, width, height, matrix, false);

有人可以帮助我吗？ 谢谢！

Answer 1

如果您想获取设备的屏幕尺寸，请按以下步骤操作

Display display = getWindowManager().getDefaultDisplay();
Point size = new Point();
display.getSize(size);
int width = size.x;
int height = size.y;

如果您在 API 中使用 < 13 then use

Display display = getWindowManager().getDefaultDisplay(); 
int width = display.getWidth();  // deprecated
int height = display.getHeight();

然后在

中使用这些值

_background = getResizedBitmap(background,height,width); 

参考 屏幕尺寸