Android Develop Tricks
设置AlertDialog的大小:
AlertDialog dialog = builder.setTitle("消息列表") .setView(layout) .create(); dialog.show(); //设置窗口的大小 dialog.getWindow().setLayout(300, 200);
dialog.show();一定要放在dialog.getWindow().setLayout(300, 200);的前面,否则不起作用。
另一种实现:
WindowManager.LayoutParams params = dialog.getWindow().getAttributes(); params.width = 300; params.height = 200; dialog.getWindow().setAttributes(params);
实际上setLayout就是对这个方法的封装:
final WindowManager.LayoutParams attrs = getAttributes(); attrs.width = width; attrs.height = height; if (mCallback != null) { mCallback.onWindowAttributesChanged(attrs); }
任意位置显示View:
通过WindowManager来实现添加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); //添加对话框 mWindowManager.addView(mDialogView, params);
任意View的触摸移动通用方法:
同样是重写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; } @Override public 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; } }
ImageView设置属性scaleType为FIT_START后去掉多余空白
imageView.setScaleType(ImageView.FIT_START); imageView.setAdjustViewBounds(true);