系統中默認的按鈕被按下的顏色和未點擊時的顏色不一樣,該種實現可以用Java代碼和XML實現。
Java代碼實現(通過StateListDrawable)
okBtn.setBackgroundDrawable(addStateDrawable(this, R.drawable.btn_normal, R.drawable.btn_ selected, R.drawable.btn_selected)); cancelBtn.setBackgroundDrawable(addStateDrawable(this, R.drawable.btn_normal, R.drawable. btn_selected, R.drawable.btn_selected)); private StateListDrawable addStateDrawable(Context context, int idNormal, int idPressed, int idFocused) { StateListDrawable sd = new StateListDrawable(); Drawable normal = idNormal == -1 ? null : context.getResources().getDrawable(idNormal) Drawable press(略);Drawable focus(略); //注意該處的順序,只要有一個狀態與之相配,背景就會被換掉 //所以不要把大範圍放在前面了,如果sd.addState(new[]{},normal)放在第一個的話,就沒有q 什麼效果了 sd.addState(new int[]{android.R.attr.state_enabled, android.R.attr.state_focused}, focus); sd.addState(new int[]{android.R.attr.state_pressed, android.R.attr.state_enabled}, pressed); sd.addState(new int[]{android.R.attr.state_focused}, focus); sd.addState(new int[]{android.R.attr.state_pressed}, pressed); sd.addState(new int[]{android.R.attr.state_enabled}, normal); sd.addState(new int[]{}, normal); return sd; }
xml方式實現時,可以先了解下對應xml的語法
<?xml version="1.0" encoding="utf-8"?> <selector xmlns:android="http://schemas.android.com/apk/res/android" android:constantSize=["true" | "false"] android:dither=["true" | "false"] android:variablePadding=["true" | "false"] > <item android:drawable="@[package:]drawable/drawable_resource" android:state_pressed=["true" | "false"] android:state_focused=["true" | "false"] android:state_selected=["true" | "false"] android:state_active=["true" | "false"] android:state_checkable=["true" | "false"] android:state_checked=["true" | "false"] android:state_enabled=["true" | "false"] android:state_window_focused=["true" | "false"] /> </selector>