Android Develop Tricks-1

Android Develop Tricks-1
Android Develop Tricks:

AlertDialog dialog = builder. setTitle ("message List "). setView (layout ). create (); dialog. show (); // set the size of the window. getWindow (). setLayout (300,200 );

Dialog. show (); Be sure to put it in front of dialog. getWindow (). setLayout (300,200); otherwise, it does not work.

Another implementation:

WindowManager.LayoutParams params = dialog.getWindow().getAttributes();params.width = 300;params.height = 200;dialog.getWindow().setAttributes(params);

In fact, setLayout is the encapsulation of this method:

        final WindowManager.LayoutParams attrs = getAttributes();        attrs.width = width;        attrs.height = height;        if (mCallback != null) {            mCallback.onWindowAttributesChanged(attrs);        }

View displayed anywhere:

Use WindowManager to add a View:

MWindowManager = getWindowManager (); LayoutInflater inflater = (LayoutInflater) getSystemService (LAYOUT_INFLATER_SERVICE); mDialogView = inflater. inflate (R. layout. dialogview, null); WindowManager. layoutParams params = new WindowManager. layoutParams (); params. height = WindowManager. layoutParams. WRAP_CONTENT; params. width = WindowManager. layoutParams. WRAP_CONTENT; params. y ++ = 100; params. x + =-30; initDialogComponents (mDialogView); // Add dialog box mWindowManager. addView (mDialogView, params );

General method for moving the touch of any View: rewrite onTouchEent

package ui;import android.content.Context;import android.util.AttributeSet;import android.util.DisplayMetrics;import android.util.Log;import android.view.MotionEvent;import android.view.WindowManager;import android.view.animation.AlphaAnimation;import android.view.animation.Animation;import android.view.animation.AnimationSet;import android.view.animation.ScaleAnimation;import android.widget.Button;/** *  * @author chenxiruanhai *  * */public class MenuButton extends Button {private Context mContext;private WindowManager mWm;int lastX;int lastY;int screenWidth;int screenHeight;public MenuButton(Context context, AttributeSet attrs) {super(context, attrs);this.mContext = context;mWm = (WindowManager) mContext.getSystemService(Context.WINDOW_SERVICE);DisplayMetrics dm = mContext.getResources().getDisplayMetrics();screenWidth = dm.widthPixels;screenHeight = dm.heightPixels;}@Overridepublic boolean onTouchEvent(MotionEvent event) {super.onTouchEvent(event);measure(0, 0);switch (event.getAction()) {case MotionEvent.ACTION_DOWN:lastX = (int) event.getRawX();lastY = (int) event.getRawY();break;case MotionEvent.ACTION_MOVE:int dx = (int) event.getRawX() - lastX;int dy = (int) event.getRawY() - lastY;int left = this.getLeft() + dx;int top = this.getTop() + dy;int right = this.getRight() + dx;int bottom = this.getBottom() + dy;if (left < 0) {left = 0;right = left + this.getWidth();}if (right > screenWidth) {right = screenWidth;left = right - this.getWidth();}if (top < 0) {top = 0;bottom = top + this.getHeight();}if (bottom > screenHeight) {bottom = screenHeight;top = bottom - this.getHeight();}this.layout(left, top, right, bottom);lastX = (int) event.getRawX();lastY = (int) event.getRawY();lastX = (int) event.getRawX();lastY = (int) event.getRawY();break;case MotionEvent.ACTION_UP:{Animation alphaAnimation = new AlphaAnimation( 0.5f,1f); alphaAnimation.setDuration(1000); Animation scaleAnimation2 = new ScaleAnimation(1.0f, .5f,1.0f,.5f); scaleAnimation2.setDuration(500); AnimationSet animationSet = new AnimationSet(true); animationSet.addAnimation(alphaAnimation); animationSet.addAnimation(scaleAnimation); animationSet.addAnimation(scaleAnimation2); animationSet.setFillAfter(true);Animation currentAnima = getAnimation();if(null!=currentAnima) {currentAnima.cancel();animationSet.reset();} startAnimation(animationSet);}break;}return true;}}

Remove unnecessary space after setting the scaleType attribute to FIT_START in ImageView

imageView.setScaleType(ImageView.FIT_START);        imageView.setAdjustViewBounds(true);