常用控件的使用方法

1.TextView:

match_parent：当前控件大小和父布局一样

wrap_parent:控件大小刚好包住内容

anroid:gravity="center" :居中

 

2.EditText:

anroid:hint="Type something here" //提示性文本

anroid:maxLines="2" //最大行数，文本向上滚动

 

3.ImageView:

anroid:src //picture's location

imageView.setImageResource(R.drawable.flower) //点击按钮切换图片

in android studio the image's format must .png

 

4.ProgressBar:

设置控件是否可见:

if(progressBar.getVisibility() == View.GONE){

                   progressBar.setVisibility(View.VISIBLE);

    }else{

                    progressBar.setVisibility(View.GONE);

                }

加减进度条:

                int progress = progressBar.getProgress();

                progress += 10;

                progressBar.setProgress(progress);

 

样式： style="?android:attr/progressBarStyleHorizontal"

 

5.AlertDialog：//弹出提示框

AlertDialog.Builder dialog =  new AlertDialog.Builder(MainActivity.this);

dialog.setTitle

dialog.setMessage

dialog.setCancelable  //是否能通过BACK退出对话 FALSE为不允许

//对话中按键监听事件

dialog.setPositiveButton("OK",new DialogInterface.OnClickListener() {

                    @Override

                    public void onClick(DialogInterface dialog, int which) {

                        imageView.setImageResource(R.drawable.a1);

                    }

                });

                dialog.setNegativeButton("Cancel",new DialogInterface.OnClickListener() {

                    @Override

                    public void onClick(DialogInterface dialog, int which) {

 

                    }

                });

 

6.Loading框

ProgressDialog.Builder dialog =  new ProgressDialog.Builder(MainActivity.this);

                dialog.setTitle("this is Dialog");

                dialog.setMessage("Loading...");

                dialog.setCancelable(false); //在代码中设置好控制取消，调用dismiss()

 dialog.show();