为了提高工作效率,对一些常见View的特殊用法作一下总结。


一、进度条对话框

       坑:https://blog.csdn.net/nailsoul/article/details/38870827 (ProgressBar占据位置但是不显示的问题)

        最近我的同事孙大姐提个需求:将进度显示框的进度条放到文字上方。

       1.使用系统的ProgressDialog

          https://www.cnblogs.com/guop/p/5139937.html  (圆形进度条与水平进度条) (注意构造方法要传theme,否则有些手机可能看不到进度条。)

          看不到进度条的还有一种情况就是没有指定ProgressBar的一个属性:

     

          

   

          注意创建ProgressDialog时不要使用Builder来创建,即:

     new ProgressDialog.Builder(mContext).create();

          用这种方式创建的ProgressDialog会不显示进度条,只会显示纯文字。

          原生的进度显示框设置样式为SPINNER,默认进度条放在文字左方,所以无法满足孙大姐的需求。

       

        2.使用AlertDialog自定义View

           正确的用法:

     progressDialog = new AlertDialog.Builder(mContext).create();     View rootView = LayoutInflater.from(mContext).inflate(R.layout.mprogress_dialog, null);     pbBar = rootView.findViewById(R.id.pb_bar);     tvMsg = (TextView) rootView.findViewById(R.id.tvMsg);     progressDialog.setView(rootView);

           注意错误的用法:

     new ProgressDialog.Builder(mContext,ProgressDialog.THEME_DEVICE_DEFAULT_DARK).create();

          上面的ProgressDialog.Builder实际上还是父类AlertDialog的类,create出来的是AlertDialog,并非ProgressDialog,无法将AlertDialog强制转换成ProgressDialog。

           也就无法使用ProgressDialog的特有方法progressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER),因此,如果想通过Builder类创建的dialog来实现圆形进度条对话框,

           只有自定义view。

         3.继承的方式

            方式1:直接继承ProgressDialog

            研究ProgressDialog的源码可以发现其onCreate方法里:

      else{            View view = inflater.inflate(a.getResourceId(                    com.android.internal.R.styleable.AlertDialog_progressLayout,                    R.layout.progress_dialog), null);            mProgress = (ProgressBar) view.findViewById(R.id.progress);            mMessageView = (TextView) view.findViewById(R.id.message);            setView(view);      }

            注意上面的R是com.android.internal.R,如果将布局引用为自己应用的app不就行了。于是继承ProgressDialog准备复写onCreate方法:

            

            可以发现会报各种引用不到的问题,因为这些变量都是父类定义的private变量。

            对于变量mContext有public访问方法

            

            对于其他没有public访问方法的private变量,该如何获取呢?

            答案:反射   (代码附于文章最后)

            

            还有一项就是系统资源文件com.android.internal.R如何获取呢?

            答案:反射   (代码附于文章最后)

            com.android.internal.R是无法在java文件里import的

            

            将私有变量和方法用反射代替之后,代码如下:

@Overrideprotected void onCreate(Bundle savedInstanceState) {        LayoutInflater inflater = LayoutInflater.from(getContext());        TypedArray a = getContext().obtainStyledAttributes(null,                SystemResourceManager.getResourceStyleableIds("AlertDialog"),                SystemResourceManager.getResourceAttrId("alertDialogStyle")                , 0);        if ((int)ReflectManger.getField(ProgressDialog.class,this,"mProgressStyle")  == STYLE_HORIZONTAL) {        /* Use a separate handler to update the text views as they         * must be updated on the same thread that created them.         */            ReflectManger.setField(ProgressDialog.class,this,"mViewUpdateHandler",new Handler() {                @Override                public void handleMessage(Message msg) {                    super.handleMessage(msg);                /* Update the number and percent */                    int progress = ((ProgressBar)(ReflectManger.getField(ProgressDialog.class,this,"mProgress"))).getProgress();                    int max = ((ProgressBar)(ReflectManger.getField(ProgressDialog.class,this,"mProgress"))).getMax();                    if (ReflectManger.getField(ProgressDialog.class,this,"mProgressNumberFormat") != null) {                        String format = (String) ReflectManger.getField(ProgressDialog.class,this,"mProgressNumberFormat");                        ((TextView)ReflectManger.getField(ProgressDialog.class,this,"mProgressNumber")).setText(String.format(format, progress, max));                    } else {                        ((TextView)ReflectManger.getField(ProgressDialog.class,this,"mProgressNumber")).setText("");                    }                    if (ReflectManger.getField(ProgressDialog.class,this,"mProgressPercentFormat") != null) {                        double percent = (double) progress / (double) max;                        SpannableString tmp = new SpannableString(((NumberFormat)ReflectManger.getField(ProgressDialog.class,this,"mProgressPercentFormat")).format(percent));                        tmp.setSpan(new StyleSpan(android.graphics.Typeface.BOLD),                                0, tmp.length(), Spannable.SPAN_EXCLUSIVE_EXCLUSIVE);                        ((TextView)ReflectManger.getField(ProgressDialog.class,this,"mProgressPercent")).setText(tmp);                    } else {                        ((TextView)ReflectManger.getField(ProgressDialog.class,this,"mProgressPercent")).setText("");                    }                }            });            View view = inflater.inflate(a.getResourceId(                    SystemResourceManager.getResourceStyleableId("AlertDialog_horizontalProgressLayout"),                    SystemResourceManager.getResourceLayoutId("alert_dialog_progress")), null);            ReflectManger.setField(ProgressDialog.class,this,"mProgress",                     view.findViewById(SystemResourceManager.getResourceId("progress"))                    );            ReflectManger.setField(ProgressDialog.class,this,"mProgressNumber",                   view.findViewById(SystemResourceManager.getResourceId("progress_number"))            );            ReflectManger.setField(ProgressDialog.class,this,"mProgressPercent",                   view.findViewById(SystemResourceManager.getResourceId("progress_percent"))            );            setView(view);        } else {            View view = inflater.inflate(a.getResourceId(                    SystemResourceManager.getResourceStyleableId("AlertDialog_progressLayout"),                    R.layout.m_progress_dialog), null);            //注意布局中id的引用:android:id="@android:id/progress"            ReflectManger.setField(ProgressDialog.class,this,"mProgress",                     view.findViewById(android.R.id.progress)            );            ReflectManger.setField(ProgressDialog.class,this,"mMessageView",                     view.findViewById(R.id.message)            );            setView(view);        }        a.recycle();        if ((int)ReflectManger.getField(ProgressDialog.class,this,"mMax") > 0) {            setMax((int)ReflectManger.getField(ProgressDialog.class,this,"mMax") );        }        if ((int)ReflectManger.getField(ProgressDialog.class,this,"mProgressVal") > 0) {            setProgress((int)ReflectManger.getField(ProgressDialog.class,this,"mProgressVal") );        }        if ((int)ReflectManger.getField(ProgressDialog.class,this,"mSecondaryProgressVal") > 0) {            setSecondaryProgress((int)ReflectManger.getField(ProgressDialog.class,this,"mSecondaryProgressVal") );        }        if ((int)ReflectManger.getField(ProgressDialog.class,this,"mIncrementBy") > 0) {            incrementProgressBy((int)ReflectManger.getField(ProgressDialog.class,this,"mIncrementBy") );        }    if ((int)ReflectManger.getField(ProgressDialog.class,this,"mIncrementSecondaryBy") > 0) {        incrementSecondaryProgressBy((int)ReflectManger.getField(ProgressDialog.class,this,"mIncrementSecondaryBy") );    }    if ( ReflectManger.getField(ProgressDialog.class,this,"mProgressDrawable") != null) {        setProgressDrawable((Drawable) ReflectManger.getField(ProgressDialog.class,this,"mProgressDrawable"));    }    if ( ReflectManger.getField(ProgressDialog.class,this,"mIndeterminateDrawable") != null) {        setIndeterminateDrawable((Drawable) ReflectManger.getField(ProgressDialog.class,this,"mIndeterminateDrawable"));    }    if ( ReflectManger.getField(ProgressDialog.class,this,"mMessage") != null) {        setMessage((CharSequence) ReflectManger.getField(ProgressDialog.class,this,"mMessage"));    }    setIndeterminate((Boolean) ReflectManger.getField(ProgressDialog.class,this,"mIndeterminate"));    try {        ReflectManger.invokeMethod(ProgressDialog.class,this,"onProgressChanged",null,null);    } catch (NoSuchMethodException e) {        e.printStackTrace();    } catch (InvocationTargetException e) {        e.printStackTrace();    } catch (IllegalAccessException e) {        e.printStackTrace();    }    super.onCreate(savedInstanceState);}

         自定义布局m_progress_dialog.xml  如下:

    <FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"        android:layout_width="match_parent"        android:layout_height="wrap_content">            <LinearLayout android:id="@+id/body"            android:orientation="horizontal"            android:layout_width="match_parent"            android:layout_height="match_parent"            android:baselineAligned="false"            android:paddingStart="8dip"            android:paddingTop="10dip"            android:paddingEnd="8dip"            android:paddingBottom="10dip">                <ProgressBar android:id="@android:id/progress"                                android:layout_width="wrap_content"                android:layout_height="wrap_content"                android:max="10000"                android:layout_marginEnd="12dip" />                <TextView android:id="@+id/message"                android:layout_width="match_parent"                android:layout_height="wrap_content"                android:layout_gravity="center_vertical" />        </LinearLayout>     </FrameLayout>

          但是复写的onCreate方法中有个问题

         view.findViewById(R.id.message)

           结果返回null,但是这个id明明是存在的。但是view.findViewById(android.R.id.progress)怎么不是null呢?

           思考半天,看下面的代码:
           

  View view = inflater.inflate(a.getResourceId(                    SystemResourceManager.getResourceStyleableId("AlertDialog_progressLayout"),                    R.layout.m_progress_dialog), null);

           R.layout.m_progress_dialog只是一个备用布局,跟本就没有加载进去。

           将上面的代码稍作修改,将getResourceId方法的第一个值传入一个非法参数0(-1试了不行),这样R.layout.m_progress_dialog就加载了,果然一切正常。

View view = inflater.inflate(a.getResourceId(//                        SystemResourceManager.getResourceStyleableId("AlertDialog_progressLayout"),                        0,                        R.layout.m_progress_dialog), null);

           但是圆形进度条不会显示,上面已经说到了,构造方法要传theme,但是传了theme之后,上面代码又会报下面的错:

            android.content.res.Resources$NotFoundException: File res/drawable-xhdpi-v4/dialog_full_holo_light.9.png from xml type layout resource ID #0x1080295

            通过debug发现,如果Dialog构造方法加了主题,resId != R.layout.m_progress_dialog

            

            如果Dialog构造方法不加主题 ,


一-2、SeekBar

 自定义样式

https://blog.csdn.net/u010029983/article/details/45222257   (推荐)

https://blog.csdn.net/qq_38407076/article/details/83012684

改变游标图片大小:https://www.cnblogs.com/welhzh/p/3711694.html



            

二、快速创建一个输入框

  Builder builder = new Builder();    builder.setTitle(title)            .setMessage(message);    final EditText et = new EditText(builder.getContext());    et.setInputType(InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD);    builder.setView(et);

       注意动态设置edittext的inputType为密码输入框为:

    InputType.TYPE_CLASS_TEXT | InputType.TYPE_TEXT_VARIATION_PASSWORD

 

三、Spinner

 快速创建spinner


private void initAreaSpinner(Spinner spinner_area) {    ArrayAdapter<CharSequence> adapter;    adapter = ArrayAdapter.createFromResource(this, R.array.area, android.R.layout.simple_spinner_item);    spinner_area.setAdapter(adapter);    spinner_area.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {        @Override        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {            switch (position){                case 0:                    sdk.setBleAreaType(BleAreaType.HENAN);                    break;                case 1:                    sdk.setBleAreaType(BleAreaType.GUIZHOU);                    break;                case 2:                    sdk.setBleAreaType(BleAreaType.GUANGXI);                    break;            }        }        @Override        public void onNothingSelected(AdapterView<?> parent) {        }    });    spinner_area.setSelection(0);}

      


四、PopWindow

       https://github.com/pinguo-zhouwei/CustomPopwindow (超级方便好用的popwindow)

        



五、NavigationView

        1.修改NavigationView中的Item的Icon大小

            https://blog.csdn.net/zuolovefu/article/details/50175245

        2.Android NavigationView 中 menu item 字体大小设置

            https://blog.csdn.net/TLD_DLT/article/details/79865525


六、TabLayout

         1.修改字体大小

            https://blog.csdn.net/qq_33919497/article/details/78548198

         2.