Effect of Europeans' textiles and metals were not as well made as Chinese.

Effect of Ming emperors disallowed foreign exploration.

2. Effect: China got isolated, they refused to let their people leave and then established certain spots where people could go, and no further.

Well, I have read this kind of question and this was a cause and effect. The story behind it is that the Ming Emperor suddenly halted further construction of ships then the Ming leaders banned ships with more than two masts. With that, there would be no further construction of ships.

After that, the Ming Emperor disallowed foreign exploration. As a result, the Europeans' textiles and metals were not as well made as Chinese. In overall, the Trade was controlled by Imperial Leaders.