android UI基础元件(上)

Textview

<TextView  android:id="@+id/text_view"  android:layout_width="match_parent"  android:layout_height="wrap_content"  android:gravity="center" //文字对齐方式 vertical  android:textSize="24sp"  android:textColor="#00ff00"  android:text="@string/this_is_view" />

-wrap_content 是元件多大他就多大 / match_parent 和父布局一样大

Button

<Button android:layout_width="wrap_content" android:layout_height="wrap_content" android:id="@+id/click_show" android:text="click_to_show" android:layout_gravity="center_vertical" android:textAllCaps="false" //文字不自动大写转换 />  Button button1=(Button)findViewById(R.id.button_1); button1.setOnClickListener(new View.OnClickListener() {     @Override     public void onClick(View view) {} //设置监听方式

EditText

editText=(EditText)findViewById(R.id.edit_text);<EditText    android:layout_width="match_parent"    android:layout_height="wrap_content"    android:id="@+id/edit_text"    android:hint="TYpe sth"     android:maxLines="1"     />      click_to_show.setOnClickListener(new View.OnClickListener() {        @Override            public void onClick(View view) {                switch (view.getId()){                    case R.id.click_show:                        String inputtext=editText.getText().toString()                           Toast.makeText(first.this,inputtext,Toast.LENGTH_LONG).show();}

ImageView

private ImageView imageView;
imageView=(ImageView) findViewById(R.id.image_view);
imageView.setImageResource(R.drawable.a2); //设置图片内容

ProgressBar

     click_to_show.setOnClickListener(new View.OnClickListener() {        @Override            public void onClick(View view) {                switch (view.getId()){                    case R.id.click_show:                        String inputtext=editText.getText().toString();                        Toast.makeText(first.this,inputtext,Toast.LENGTH_LONG).show();                        imageView.setImageResource(R.drawable.a2);                        if (progressBar.getVisibility() == View.GONE){                           //gone是不可见 invisible透明仍佔大小 visible 可见//                            要在VIEW使用则是找visiblitiy这个属性//                           progressBar.setVisibility(View.VISIBLE);                            int pro=progressBar.getProgress();                            pro=pro+10;                            progressBar.setProgress(pro);                        }//                        else{//                            progressBar.setVisibility(View.GONE);//                        }                        break;                        default:                            break;                }            }    });